FINAL
Mitigated Negative Declaration/Initial Study
Heart of the City Specific Plan Amendment
for Rancho Coronado
City of San Marcos, California
April 2014
Table of Contents
Heart of the City Specific Plan Amendment-Rancho Coronado i City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
TABLE OF CONTENTS
1.0 INTRODUCTION AND SUMMARY ......................................................................................... 1-1
2.0 CORRECTIONS AND ADDITIONS ........................................................................................... 2-1
2.1 REVISED AND SUPPLEMENTAL TEXT................................................................................ 2-1
3.0 RESPONSE TO WRITTEN COMMENTS ................................................................................... 3-1
4.0 MITIGATION MONITORING AND REPORTING PROGRAM ..................................................... 4-1
List of Tables
Table 3-1. Comment Letters ................................................................................................................... 3-1
Table 4-1. Mitigation Measures .............................................................................................................. 4-2
Table 4-2. Design Considerations for the Project ................................................................................. 4-14
Table of Contents
Heart of the City Specific Plan Amendment-Rancho Coronado ii City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
THIS PAGE INTENTIONALLY LEFT BLANK.
1.0 Introduction and Summary
Heart of the City Specific Plan Amendment-Rancho Coronado 1-1 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
1.0 INTRODUCTION AND SUMMARY
This Final Initial Study and Mitigated Negative Declaration (IS/MND) has been prepared in accordance
with the California Environmental Quality Act (CEQA) as amended (Public Resources Code Section 21000
et seq.) and the CEQA Guidelines (California Administrative Code Section 15000 et seq.).
CEQA Guidelines Section 15074(b) and (d) state:
“(b) Prior to approving a project, the decision-making body of the lead agency shall
consider the proposed negative declaration or mitigated negative declaration together
with any comments received during the public review process. The decision-making
body shall adopt the proposed negative declaration or mitigated negative declaration
only if it finds on the basis of the whole record before it (including the initial study and
any comments received), that there is no substantial evidence that the project will have
a significant effect on the environment and that the negative declaration or mitigated
negative declaration reflects the lead agency's independent judgment and analysis.”
“(d) When adopting a mitigated negative declaration, the lead agency shall also adopt a
program for reporting on or monitoring the changes which it has either required in the
project or made a condition of approval to mitigate or avoid significant environmental
effects.”
In accordance with this requirement, the Heart of the City Specific Plan Amendment (Rancho Coronado)
IS/MND is comprised of the following:
• Draft Initial Study and Mitigated Negative Declaration February 2014 (SCH No. 2014021007);
• This Final IS/MND document, April 2014, that incorporates the information required by §15074
(included in this document); and
• A Mitigation Monitoring and Reporting Program (included in this document).
Format of the Final IS/MND
This document is organized as follows:
Section 1.0 Introduction and Summary
This section describes CEQA requirements and content of this Final IS/MND.
Section 2.0 Corrections and Additions
This section provides a list of those revisions made to the Draft IS/MND text as a result
of comments received and/or errors and omissions discovered subsequent to release of
the Draft IS/MND for public review.
1.0 Introduction and Summary
Heart of the City Specific Plan Amendment-Rancho Coronado 1-2 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Section 3.0 Responses to Comment Letters Received on the Draft IS/MND
This section provides copies of the comment letters received and individual responses
to written comments.
Section 4.0 Mitigation Monitoring and Reporting Program
This section provides a program of monitoring or reporting to ensure that the
provisions or revisions are complied with during implementation of the project.
2.0 Corrections and Additions
Heart of the City Specific Plan Amendment-Rancho Coronado 2-1 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
2.0 CORRECTIONS AND ADDITIONS
This section contains revisions to information included in the Draft IS/MND (February 2014) based upon
additional or revised information required to prepare a response to a specific comment. Please see
copies of the letters and responses in Section 3.0, Responses and Comments of this Final IS/MND, as
applicable.
2.1 REVISED AND SUPPLEMENTAL TEXT
The following table summarizes the changes to the Draft IS/MND. These changes were based upon
public comments on the Draft IS/MND, incorporation of the Water and Sewer Study (Vallecitos Water
District 2014) and the Least Bell’s Vireo (LBV) Survey (Helix 2012) into the Final IS/MND, as well as
additional clean up items due to project refinements. The complete Water and Sewer Study is included
as Appendix N of the Final IS/MND and the LBV survey is included as Appendix O. None of the analysis
conclusions for water and sewer changed. Impacts remain less than significant.
Pages IS/MND Section Summary of Change
3 1.F – Project Entitlements Discretionary actions with associated reference numbers updated in
the document. Ministerial approval also identified.
8 II. Project Descriptions Information regarding boundary adjustment for sewer service.
11 Table 2 Clarified the requirements for pipeline improvements for the project.
40/41 IV-c – Cultural Resources Revisions to text and Table 7a to note mitigation requirement for
detention basin (0.2 acres).
51 V.b – Cultural Resources Added information on what tribes provided correspondence for the
project.
51 - 53 V.b – Cultural Resources Minor modification to cultural resources mitigation measures based
upon input from the Tribes and the San Diego County Archaeological
Society.
113 XVI.b – Traffic Added statement about assumptions for ramp meter flow rates.
120/121 XVI.b – Traffic Ramp meter delay analysis refined. Based upon the new analysis, the
project would not have a significant impact at the Twin Oaks Valley
Road / SR-78 Eastbound On-Ramp in the Horizon Year 2030
condition. Mitigation measures TR-3 would no longer be required.
124/125 XVII.b – Utilities and Service
Systems
Updated water demand calculation on Table 41 and associated text.
125 XVII.b – Utilities and Service
Systems
Modified water storage conclusion to note the project decreases
demand compared to what was assumed for the project site in the
2008 VWD Master Plan and no further storage upgrades are needed.
126 XVII.b – Utilities and Service
Systems
Added Table 42, which shows the wastewater flows for the project
site for the 2008 VWD Master Plan and the proposed project.
Refined wastewater collection system analysis text to note the
pipeline improvements required for the project.
128 XVII.d – Utilities and Service
Systems
Updated the water supply analysis to note the water demand for the
project and that the expected demand is less than what was
2.0 Corrections and Additions
Heart of the City Specific Plan Amendment-Rancho Coronado 2-2 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Pages IS/MND Section Summary of Change
anticipated per the VWD 2008 Master Plan.
138 VIII – Mitigated Negative
Declaration
Updated mitigation measures MM-BIO-1A to reflect the increase of
mitigation from 1.07 to 1.27 acres to reflect detention basin
mitigation requirements.
140-142 VIII – Mitigated Negative
Declaration
Updated cultural resources mitigation measures to reflect input from
the Tribes and San Diego County Archaeological Society.
144 A VIII – Mitigated Negative
Declaration
Mitigation measures MM-TR-3 no longer required due to refinement
of analysis.
Appendix N Appendices Added Water and Sewer Study (VWD 2014) to the Technical
Appendices.
Appendix O Appendices Added Least Bell’s Vireo report (Helix 2012) to the Technical
Appendices.
Ramp Meter Analysis Refinement
Based upon a refinement in the ramp meter assumptions and analysis, the project is no longer
identified as having an impact in Horizon Year 2030 at the Twin Oaks Valley Road / SR-78 Eastbound On-
Ramp and mitigation measure MM-TR-3 is no longer required. The ramp meter analysis has been
refined in the CEQA document and reads as follows (strike out for removed text/ underline for added
text).
Revised text – pages 120 and 121:
The results of the ramp metering analysis show that under Horizon Year conditions, the addition of
project-related traffic to the Twin Oaks Valley Road / SR-78 Eastbound On-Ramp during the p.m. peak
hour is forecast to result in a ramp meter delay that exceeds the policy threshold of 15 minutes. The
increase in ramp meter delay associated with project-related traffic is forecast to result in an increase in
delay that exceeds the significant impact threshold of 2 minutes according to the SANTEC/ITE TIS
Guidelines.
As previously discussed, the existing ramp meter flow rates were used for all future analysis scenarios.
This assumption provided a conservative analysis because there are planned capacity improvements on
eastbound SR-78 through the study area that would likely allow for adjustments in the future ramp
meter rate at the Twin Oaks Valley Road Eastbound On-Ramp.
The planned freeway improvements for eastbound SR-78 through the study area are listed below:
• One new auxiliary lane will be provided, extending from immediately upstream of the San
Marcos Boulevard On-Ramp and connecting with the existing auxiliary lane that is currently
provided from the San Marcos Boulevard eastbound on-ramp to the Twin Oaks Valley Road
eastbound off-ramp.
• A second eastbound auxiliary lane will be provided that will begin at the San Marcos Boulevard
eastbound on-ramp and will terminate at the Twin Oaks Valley Road eastbound off-ramp. The
2.0 Corrections and Additions
Heart of the City Specific Plan Amendment-Rancho Coronado 2-3 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
first auxiliary lane will be extended east though the Twin Oaks Valley Road interchange and will
terminate at the Woodland Parkway/Barham Drive eastbound off-ramp.
• The lengths of the San Marcos Boulevard and Twin Oaks Valley Road eastbound on-ramps
would be increased to provide longer acceleration and merging distances from the ramp meters
to the freeway ramp gore points.
• A new eastbound auxiliary lane will be provided from the reconfigured Barham Drive/Woodland
Parkway interchange that will extend east to connect with the existing auxiliary lane that
currently begins immediately east of the SPRINTER overcrossing.
The improvements listed above are planned to be completed prior to the year 2030 and are
included in the Horizon Year 2030 conditions analysis.
The existing ramp meter flow rate of 570 vehicles per hour during the p.m. peak period equates to
approximately 9.5 cycles per minute at the Twin Oaks Valley Road Eastbound On-Ramp. Based on
the existing p.m. ramp meter rate, the forecast ramp meter delay is 17 minutes under Horizon Year
2030 conditions with the proposed project. If the p.m. ramp meter flow rate were adjusted slightly
to 600 vehicles per hour, the forecast ramp meter delay under 2030 conditions with the project
would decrease to 13 minutes, which is equivalent to the forecast p.m. ramp meter delay without
the project. The adjustment to 600 vehicles per hour is equivalent to 10 cycles per minute, a
difference of only one-half cycle per minute.
This adjustment in the p.m. ramp meter rate should be feasible based on the expected
improvement in freeway operations when the planned improvements are completed. Therefore, it
is reasonable to expect that the planned improvements along eastbound SR-78 would reduce the
identified ramp meter impact to a level that is less than significant, and no mitigation measures
would be required.
deficient ramp meter delay under Horizon Year 2030 conditions. Therefore, the project results in a
significant impact at the Twin Oaks Valley Road / SR-78 Eastbound On-Ramp and mitigation
measures are required (Impact TR-3). There are two options to reduce this impact to below a level
of significance:
MM-TR-3 One of the following options shall be implemented at the intersection of Twin Oaks
Valley Road / SR-78 EB On-Ramp:
• Adjusting the ramp meter rate to accommodate the increase in demand at
the on-ramp; or
• Converting the existing HOV lane to a third SOV lane on the on-ramp to
increase on-ramp capacity.
Implementation of mitigation measure MM-TR-3, which will be required as a condition of project
approval will reduce the deficient ramp meter delay under the Horizon Year 2030 conditions at the
Twin Oaks Valley Road / SR-78 Eastbound On-Ramp during the p.m. peak hour to below a level of
significance.
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-1 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
3.0 RESPONSE TO WRITTEN COMMENTS
Section 3.0 contains responses to all comment letters received on the February 2014 Draft IS/MND. A
total of seven comment letters were received during the comment period, which closed March 7, 2014
(Table 3-1).
Table 3-1. Comment Letters
Number Letter Preparer Date
1 Office of Planning and Research – State Clearinghouse 3/7/14
2 United States Fish and Wildlife Service/California Department of Fish and Game 3/7/14
3 Native American Heritage Commission 3/4/14
4 Vallecitos Water District 2/25/14
5 San Diego Archeological Society 3/5/14
6 San Luis Rey Band of Mission Indians 3/5/14
7 U.S. Department of Homeland Security/FEMA 3/11/14
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-2 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
1-1
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-3 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-4 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
1-2
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-5 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
1-2
Cont.
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-6 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Letter 1
Office of Planning and Research / State Clearinghouse
1-1 This comment states that the State Clearinghouse submitted the MND to select state agencies
for review. The letter also confirms that the City complied with the State Clearinghouse review
requirements for draft environmental documents pursuant to the California Environmental
Quality Act. In closing, this comment does not raise any environmental issues so no further
response is warranted.
1-2 This attachment to the letter from OPR/State Clearinghouse is comments from the Native
American Heritage Commission (NAHC). The NAHC submitted these same comments directly to
the city. Please see comment letter
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-7 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
2-1
2-2
2-4
2-3
2-5
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-8 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
2-6
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-9 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Letter 2
United States Fish and Wildlife Service/California Department of Fish and Wildlife
2-1 This comment provides introductory remarks. This comment does not raise any specific issues
on the environmental document and no additional response is warranted.
2-2 This comment request tables showing changes to the habitat types within the HLP. The
following tables are provided based upon this comment:
Proposed Hardline Vegetation Changes
Vegetation Type
Removed from
Adopted Hardline Area
(acres)
Added to
Adopted Hardline Area
(acres)
Total
Difference
(acres)
Sensitive
Southern riparian forest 0.00 0.12 0.12
Coastal sage scrub 0.00 2.40 2.40
Southern mixed chaparral 0.00 0.00 0.00
Subtotal Sensitive 0.00 2.52 +2.52
Non-Sensitive
Eucalyptus woodland 0.20 1.00 0.80
Disturbed 0.40 0.20 -0.20
Subtotal Non-sensitive 0.60 1.20 +0.70
TOTAL 0.60 3.72 +3.12
Comparison of Vegetation Communities in the Approved HLP Preserve vs. Proposed HLP Preserve
Vegetation Community
Existing Preserve
(acres)
Proposed Preserve
(acres)
Change
(acres)
Southern riparian forest (61300) 0.58
0.701
0.121
Diegan coastal sage scrub (32500) 89.02
91.42
2.4
Southern mixed chaparral (37120) 11.5 11.5 0
Eucalyptus woodland (79000) 2.4 3.2 0.8
Disturbed habitat (11300) 3.63
3.43
(0.2)
Total 107.1 110.24 3.1
4
1Does not include acres that will also be restored within the riparian mitigation area within the HLP Preserve.
2Does not include 2.4 acres of sage scrub restoration required by the HLP.
32.4 acres will be restored to sage scrub as required by the HLP.
4Does not include additional acres conserved as part of wetland restoration onsite outside of the HLP Preserve.
2-3 The 2012 Least Bell’s Vireo (LBV) survey report is included as Appendix O of the Final IS/MND.
The results of the LBV survey were included in the Draft IS/MND in the Biological Resources
section.
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-10 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
2-4 The City does not see the need for a specific drought contingency plan. If the project has not
met success criteria as a result of drought conditions, the applicant would need to continue the
restoration effort unless otherwise agreed to by the resource agencies. If success criteria have
been met at the end of five years, the restoration would have been off of irrigation for a
minimum of two years, and any affects of a drought would already be accounted for in meeting
(or not meeting) success criteria. No changes were made to the Final IS/MND based upon this
comment.
2-5 This comment provides closing remarks and does not raise any additional comments on the
environmental document.
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-11 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
3-1
3-2
3-3
3-4
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-12 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
3-5
3-6
3-8
3-7
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-13 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-14 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Letter 3
Native American Heritage Commission
3-1 This comment notes the project subject to SB-18. The City sent out letters to the Native
American community to and has been consulting with interested Tribes and their input has
been incorporated into the cultural resources mitigation measures.
3-2 Based upon the cultural resources study prepared for the project (ASM 2014), there are no
cultural resources on the project site.
3-3 In order to account for the potential for encountering unidentified cultural resources, mitigation
was included in the MND requiring an archaeological and Native American monitor. Please see
mitigation measures. These measures are also provided here:
MM-CR-1 An archeological monitor and a Luiseño Native American monitor shall be
present during all earth moving and grading activities to assure that any
potential cultural resources, including tribal, found during project grading be
protected.
MM CR-2 Prior to beginning project construction, the Project Applicant shall retain a San
Diego County qualified archaeological monitor to monitor all ground-disturbing
activities in an effort to identify any unknown archaeological resources. Any
newly discovered cultural resource deposits shall be subject to cultural
resources evaluation which shall include archaeological documentation, analysis
and report generation.
MM-CR-3 At least 30 days prior to beginning project construction, the Project Applicant
shall enter into a Cultural Resource Treatment and Monitoring Agreement (also
known as a pre-excavation agreement) with a Luiseño Tribe. The Agreement
shall address the treatment of known cultural resources, the designation,
responsibilities, and participation of professional Native American Tribal
monitors during grading, excavation and ground disturbing activities; project
grading and development scheduling; terms of compensation for the monitors;
and treatment and final disposition of any cultural resources, sacred sites, and
human remains discovered on site.
MM-CR-4 Prior to beginning project construction, the Project Archaeologist shall file a
pre-grading report with the City to document the proposed methodology for
grading activity observation, which will be determined in consultation with the
Luiseño Tribe referenced in MM-CR-3. . Said methodology shall include the
requirement for a qualified archaeological monitor to be present and to have
the authority to stop and redirect grading activities. In accordance with the
agreement required in MM-CR-3, the archaeological monitor’s authority to stop
and redirect grading will be exercised in consultation with the Luiseño Native
American monitor in order to evaluate the significance of any archaeological
resources discovered on the property. Tribal and archaeological monitors shall
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-15 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
be allowed to monitor all grading, excavation, and groundbreaking activities,
and shall also have the authority to stop and redirect grading activities.
MM-CR-5 The landowner shall relinquish ownership of all cultural resources collected
during the grading monitoring program and from any previous archaeological
studies or excavations on the project site to the appropriate Tribe for proper
treatment and disposition per the Cultural Resource Treatment and Monitoring
Agreement referenced in MM-CR-3. All cultural materials that are deemed by
the Tribe to be associated with burial and/or funerary goods will be repatriated
to the Most Likely Descendant as determined by the Native American Heritage
Commission per California Public Resources Code Section 5097.98.
MM-CR-6 All sacred sites, should they be encountered within the project area, shall be
avoided and preserved as the preferred mitigation, if feasible.
MM-CR-7 If human remains are encountered, California Health and Safety Code Section
7050.5 states that no further disturbance shall occur until the San Diego County
Coroner has made the necessary findings as to origin. Further, pursuant to
California Public Resources Code Section 5097.98(b) remains shall be left in
place and free from disturbance until a final decision as to the treatment and
disposition has been made. Suspected Native American remains shall be
examined in the field and kept in a secure location at the site If the San Diego
County Coroner determines the remains to be Native American, the
Native American Heritage Commission (NAHC) must be contacted within
24 hours. The NAHC must them immediately notify the “most likely
descendant(s)” of receiving notification of the discovery. The most likely
descendants(s) shall then make recommendations within 48 hours, and engage
in consultation concerning treatment of remains as provided in Public
Resources Code 5097.98.3.
MM-CR-8 If inadvertent discoveries of subsurface archaeological/cultural resources are
discovered during grading, the Developer, the project archaeologist, and the
Luiseño Tribe under agreement with the landowner described in MM-CR-3 shall
assess the significance of such resources and shall meet and confer regarding
the mitigation for such resources. Pursuant to California Public Resources Code
Section 21083.2(b) avoidance is the preferred method of preservation for
archaeological resources. If the Developer, the project archaeologist and the
Tribe cannot agree on the significance of mitigation for such resources, these
issues will be presented to the Planning Director for decision. The Planning
Director shall make a determination based upon the provisions of the California
Environmental Quality Act with respect to archaeological resources and shall
take into account the religious beliefs, customs, and practices of the Tribe.
Notwithstanding any other rights available under law, the decision of the
Planning Director shall be appealable to the Planning Commission and/or City
Council.
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-16 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
3-4 There is no federal nexus with the project thus the National Environmental Policy Act and
Section 106 of the National Historic Preservation Act.
3-5 A cultural resources report was prepared for the project and no resources were identified on
the project site. Thus no site forms were prepared.
3-6 As part of the cultural resources report preparation, letters were sent to the appropriate Native
American contact for the project. Additionally, the City reached out the local Tribes as part of
the SB18 process.
3-7 Implementation of mitigation measures identified for the project (MM-CR-1 through MM-CR-8)
will be required as a condition of project approval. Additionally, a Mitigation, Monitoring and
Reporting Program (MMRP) will be adopted for the project. The mitigation requires
coordination with the culturally affiliated Native Americans if resources are identified during
project grading.
3-8 Mitigation Measure MM-CR-8 identifies the steps that shall be implemented in the event of
accidental discovery of any human remains on the site.
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-17 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
4-1
4-2
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-18 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
4-4
4-3
4-2
Cont.
4-5
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-19 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
4-6
4-5
Cont.
4-8
4-7
4-9
4-10
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-20 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-21 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Letter 4
Vallecitos Water District
4-1 This comment states that the conclusion regarding wastewater treatment requirements of the
applicable Regional Water Quality Control Board is acceptable. This comment does not raise any
additional issues with the environmental document; therefore, no additional response is
warranted.
4-2 The wastewater flow generation quantities have been updated in the Final IS/MND. Please see
Table 42. As note by this comment, this results in deficiencies in the District’s infrastructure.
The project will pay Wastewater Facility Fees per Ordinance No. 177 as well as Wastewater
Capital Facility Fees per Ordinance No. 176. These fee payments are identified in Table 1 as
design features for the project. Additionally, as noted in Table 1 of the Final IS/MND, the
project will upsize approximately 2,700 feet of an existing 8-inch wastewater collection pipe in
Craven Road. The improvement includes 700 feet of 10-inch pipeline and 2,000 feet of 12-inch
pipeline. This meets the recommendations indentified in VWD’s letter.
4-3 This comment addresses threshold “c” under the Utilities and Services Systems analysis section
of the IS/MND. It addresses stormwater facilities and is not applicable to VWD, as noted in this
comment. This comment does not raise any additional issues with the environmental
document; therefore no additional response is warranted.
4-4 Water demand quantities have been updated in Table 41 of the Final IS/MND to reflect the
Water and Sewer Study prepared by VWD (2014). The project will install a new 14-inch
diameter water main loop from the intersection of Twin Oaks Valley Road and South Village
Drive to the existing 14-inch water main, approximately 1,100 feet north of South Lake Pump
Station. This is also noted as a project design feature in Table 1 of the Final IS/MND. The project
will also relocate a 14-inch water main that traverses the development, as requested by this
comment.
4-5 Please see response 4-2. The project will pay the fees identified in this comment (Wastewater
Impact Fees and Capital Facility Fees) as well as upsize the segments within Craven Road, as
identified in this comment.
4-6 The City recognizes that the project is within VWD’s district boundary for water service but will
need to be annexed in to VWD’s service boundary for sewer service. This is an intra-district
annexation and will not require LAFCO approval or process. This requirement has been
identified in the project description of the Final IS/MND. Please see page 8 of the Final IS/MND.
4-7 This comment address VWD’s existing access and pipeline easements. As a condition of project
approval the project applicant will be required to dedicate new easements that are acceptable
to VWD.
4-8 As a condition of project approval, the project applicant will be required to coordinate with
VWD to ensure that relocation and construction of physical access to South Lake Pump Station,
South Lake, and the dam will be provided. The access shall be approved by VWD.
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-22 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
4-9 Design and construction of the ultimate VWD spillway will be required as a condition of project
approval. The following language is included as a condition of approval for the project and a
note shall be placed on the final map reflecting this condition:
Prior to recordation of the final map, the applicant, Aggregate Pacific
Southwest, Inc. shall post a security for the design, permitting, construction,
and inspection of the ultimate South Lake spillway. The applicant, Hanson
Aggregate Pacific Southwest, Inc, shall obtain State Division of Safety of Dam
(DSOD) and Vallecitos Water District (VWD) approval of the South Lake Dam
ultimate spillway construction documents prior to 25% of residential building
permit issuance. No additional building permits will be issued without said
spillway approval. Furthermore, the applicant, Hanson Aggregate Pacific
Southwest, Inc., shall construct the South Lake Dam ultimate spillway prior to
75% of residential building permit issuance. No additional building permits will
be issued without said spillway construction. Security will be returned to the
applicant once the ultimate spillway construction has been accepted by the
jurisdictional agencies.
In addition, the applicant, Hanson Aggregate Pacific Southwest, Inc., shall
process a boundary adjustment with APN 222-190-02 (VWD) which results in
the spillway being located on VWD property. Said boundary adjustment shall
be recorded prior to construction of the ultimate spillway.
4-10 The City understands that VWD will not approve proposed grading on their access, easements
and spillway area until certain requirements are met to VWD’s satisfaction. The City is including
VWD’s requirement as conditions of project approval for the applicant.
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-23 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
5-3
5-1
5-2
5-4
5-5
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-24 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
5-6
5-5
Cont.
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-25 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Letter 5
San Diego County Archeological Society
5-1 This comment provides introductory remarks and notes that the SDCAS reviewed the cultural
resources report and concurs with the recommendation for an archaeological and Native
American monitor.
5-2 This comment states that the SDCAS concurs with mitigation measures MM-CR-1, MM-CR-4,
MM-CR-6, MM-CR-7, and MM-CR-8 as written. It should be noted that based upon input from
local Tribes, there were some refinements to some of the mitigation measures. Tracked
changed version of the mitigation measures are included in the Final IS/MND. The final version
of the mitigation measures is presented here:
MM-CR-1 An archeological monitor and a Luiseño Native American monitor shall be
present during all earth moving and grading activities to assure that any
potential cultural resources, including tribal, found during project grading be
protected.
MM CR-2 Prior to beginning project construction, the Project Applicant shall retain a San
Diego County qualified archaeological monitor to monitor all ground-disturbing
activities in an effort to identify any unknown archaeological resources. Any
newly discovered cultural resource deposits shall be subject to cultural
resources evaluation, which shall include archaeological documentation,
analysis and report generation.
MM-CR-3 At least 30 days prior to beginning project construction, the Project Applicant
shall enter into a Cultural Resource Treatment and Monitoring Agreement (also
known as a pre-excavation agreement) with a Luiseño Tribe. The Agreement
shall address the treatment of known cultural resources, the designation,
responsibilities, and participation of professional Native American Tribal
monitors during grading, excavation and ground disturbing activities; project
grading and development scheduling; terms of compensation for the monitors;
and treatment and final disposition of any cultural resources, sacred sites, and
human remains discovered on site.
MM-CR-4 Prior to beginning project construction, the Project Archaeologist shall file a
pre-grading report with the City to document the proposed methodology for
grading activity observation, which will be determined in consultation with the
Luiseño Tribe referenced in MM-CR-3. . Said methodology shall include the
requirement for a qualified archaeological monitor to be present and to have
the authority to stop and redirect grading activities. In accordance with the
agreement required in MM-CR-3, the archaeological monitor’s authority to stop
and redirect grading will be exercised in consultation with the Luiseño Native
American monitor in order to evaluate the significance of any archaeological
resources discovered on the property. Tribal and archaeological monitors shall
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-26 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
be allowed to monitor all grading, excavation, and groundbreaking activities,
and shall also have the authority to stop and redirect grading activities.
MM-CR-5 The landowner shall relinquish ownership of all cultural resources collected
during the grading monitoring program and from any previous archaeological
studies or excavations on the project site to the appropriate Tribe for proper
treatment and disposition per the Cultural Resource Treatment and Monitoring
Agreement referenced in MM-CR-3. All cultural materials that are deemed by
the Tribe to be associated with burial and/or funerary goods will be repatriated
to the Most Likely Descendant as determined by the Native American Heritage
Commission per California Public Resources Code Section 5097.98.
In the event that curation of cultural resources is required, curation shall be
conducted by an approved facility and the curation shall be guided by California
State Historic Resource Commissions Guidelines for the Curation of
Archaeological Collections. The City of San Marcos shall provide the developer
final curation language and guidance on the project grading plans prior to
issuance of the grading permit, if applicable, during project construction.
MM-CR-6 All sacred sites, should they be encountered within the project area, shall be
avoided and preserved as the preferred mitigation, if feasible.
MM-CR-7 If human remains are encountered, California Health and Safety Code Section
7050.5 states that no further disturbance shall occur until the San Diego County
Coroner has made the necessary findings as to origin. Further, pursuant to
California Public Resources Code Section 5097.98(b) remains shall be left in
place and free from disturbance until a final decision as to the treatment and
disposition has been made. Suspected Native American remains shall be
examined in the field and kept in a secure location at the site If the San Diego
County Coroner determines the remains to be Native American, the Native
American Heritage Commission (NAHC) must be contacted within 24 hours. The
NAHC must them immediately notify the “most likely descendant(s)” of
receiving notification of the discovery. The most likely descendants(s) shall
then make recommendations within 48 hours, and engage in consultation
concerning treatment of remains as provided in Public Resources Code
5097.98, .3.
MM-CR-8 If inadvertent discoveries of subsurface archaeological/cultural resources are
discovered during grading, the Developer, the project archaeologist, and the
Luiseño Tribe under agreement with the landowner described in MM-CR-3 shall
assess the significance of such resources and shall meet and confer regarding
the mitigation for such resources. Pursuant to California Public Resources Code
Section 21083.2(b) avoidance is the preferred method of preservation for
archaeological resources. If the Developer, the project archaeologist and the
Tribe cannot agree on the significance of mitigation for such resources, these
issues will be presented to the Planning Director for decision. The Planning
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-27 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Director shall make a determination based upon the provisions of the California
Environmental Quality Act with respect to archaeological resources and shall
take into account the religious beliefs, customs, and practices of the Tribe.
Notwithstanding any other rights available under law, the decision of the
Planning Director shall be appealable to the Planning Commission and/or City
Council.
5-3 Mitigation measure MM-CR-2 was revised to reflect this comment. The measure concludes by
stating “Any newly discovered cultural resource deposits shall be subject to cultural resources
evaluation, which shall include archaeological documentation, analysis and report generation.“
5-4 The SDCAS did not have any comments on mitigation measure MM-CR-3. This comment does
not raise any environmental issues; therefore no additional response is provided.
5-5 The City has coordinated closely with local Tribes to generated mitigation language that was
acceptable to their group. The resulting mitigation measures, MM-CR-1 through MM-CR-8
reflect the requests of the Tribes. Mitigation measures CR-5 has been revised to note that In the
event that curation of cultural resources is required, curation shall be conducted by an
approved facility and the curation shall be guided by California State Historic Resource
Commissions Guidelines for the Curation of Archaeological Collections. The City of San Marcos
shall provide the developer final curation language and guidance on the project grading plans
prior to issuance of the grading permit, if applicable, during project construction.
5-6 This comment provides closing remarks and does not raise any issues on the environmental
document, therefore no additional response is provided.
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-28 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
6-1
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-29 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
6-1
Cont.
6-2
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-30 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
6-3
6-2
Cont.
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-31 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
6-5
6-3
Cont.
6-4
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-32 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
6-6
6-7
6-5
Cont.
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-33 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-34 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Letter 6
San Luis Rey Band of Mission Indians
6-1 This comment provides opening remarks and indicates that requests that revisions to the
cultural resource mitigation measures be made in the Final CEQA document. The specific
requests are detailed in subsequent comments. Please see responses, below.
6-2 The City recognizes that the Native American monitor and the archeological monitor will have
join authority to divert or halt ground disturbing operations should a cultural resource be
identified. Mitigation measure MM-CR-3 addresses the participation of a Native American Tribal
monitor during project construction. Implementation of mitigation measures MM-CR-3 will be
required as a condition of project approval.
6-3 This comment addresses repatriation of cultural resources to the Tribe. Mitigation measure
MM-CR-5 addresses repatriation.
6-4 Mitigation measures MM-CR-6 addresses sacred sites. Specifically, All sacred sites, should they
be encountered within the project area, shall be avoided and preserved as the preferred
mitigation, if feasible.
6-5 This comment addresses Tribal notification in the event that cultural resources are found during
project grading. Per mitigation measure MM-CR-3, a Native American Tribal monitor will be
required for the project.
6-6 No fill will be brought onto the project site. As noted in the project description for the project,
earthwork quantities will balance on site.
6-7 This comment provides closing remarks and does not raise any additional environmental issues.
Therefore, no further response is warranted.
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-35 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
7-1
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-36 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
7-1
Cont.
3.0 Response to Written Comments
Heart of the City Specific Plan Amendment-Rancho Coronado 3-37 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Letter 7
U.S. Department of Homeland Security/FEMA
7-1 The project site is not in a FEMA mapped floodplain or floodway. In fact, the panel for the site
has not even been printed. Therefore, the comments in this letter do not apply to the project or
project site and no additional responses are warranted.
4.0 Mitigation Monitoring and Reporting Program
Heart of the City Specific Plan Amendment-Rancho Coronado 4-1 City of San Marcos
Final Initial Study/Mitigated Negative Declaration March 2014
4.0 MITIGATION MONITORING AND REPORTING PROGRAM
4.1 INTRODUCTION AND SUMMARY
Pursuant to Section 21081.6 of the Public Resources Code and the California Environmental Quality Act
(CEQA) Guidelines Section 15097, public agencies are required to adopt a monitoring or reporting
program to assure that mitigation measures and revisions identified in the Mitigated Negative
Declaration (MND) are implemented. As stated in Section 21081.6 of the Public Resources Code:
“… the public agency shall adopt a reporting or monitoring program for the changes
made to the project or conditions of project approval, adopted in order to mitigate or
avoid significant effects on the environment.”
Pursuant to Section 21081(a) of the Public Resources Code, findings must be adopted by the decision
makers coincidental to certification of the MND. The Mitigation Monitoring and Reporting Program
(MMRP) must be adopted when making the findings (at the time of approval of the project).
As defined in the CEQA Guidelines, Section 15097, “reporting” is suited to projects that have readily
measureable or quantitative measures or which already involve regular review. “Monitoring” is suited
to projects with complex mitigation measures, such as wetland restoration or archaeological protection,
which may exceed the expertise of the local agency to oversee, are expected to be implemented over a
period of time, or require careful implementation to assure compliance. Both reporting and monitoring
would be applicable to the proposed project.
The Initial Study/ Mitigated Negative Declaration prepared for the Heart of the City Specific Plan
Amendment (Rancho Coronado) (SCH No. 2014021007) provided an analysis of the environmental
effects resulting from construction and operation of the project.
4.2 MITIGATION MATRIX
To sufficiently track and document the status of mitigation measures, a mitigation matrix has been
prepared and includes the following components:
• Impact
• Mitigation Measure
• Action
• Timing
• Responsibility
The mitigation matrix is included in Table 4-1. Additionally, the project will be required to adhere to the
design features presented in Table 4-2.
4.0 Mitigation Monitoring and Reporting Program
Heart of the City Specific Plan Amendment-Rancho Coronado 4-2 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Table 4-1. Mitigation Measures
Impact Mitigation Measure Action Timing Responsibility
BIOLOGICAL RESOURCES
The following project design
measure shall be carried
forward from the HLP
conditions to minimize
impacts to biological
resources and are identified
as mitigation measures for
the project. Implementation
of this mitigation measures
will be required as a
condition of project approval.
MM-BIO-A The clearing and grubbing of sensitive
habitats shall occur outside of the bird breeding season
(February 15 to August 31), unless a qualified biologist
demonstrates to the satisfaction of the City and the Wildlife
Agencies that all nesting is complete. The qualified biologist
would need to be federally permitted for coastal California
gnatcatcher if the habitat being cleared has potential to
support these species.
Avoid clearing or
grubbing activities during
the avian breeding
season or perform a pre-
construction survey to
ensure no nests are
present. Results of the
survey shall be submitted
to the Wildlife Agencies
and the Planning
Director.
Avoidance covers
the period of
February 15 to
August 31.
Preconstruction
surveys would be
within three days of
propose clearing
and grubbing.
Applicant, Project
Biologist
The following project design
measure shall be carried
forward from the HLP
conditions to minimize
impacts to biological
resources and are identified
as mitigation measures for
the project. Implementation
of this mitigation measures
will be required as a
condition of project approval.
MM-BIO-B Temporary perimeter fencing shall be
installed to separate the proposed development and the fuel
management zones from any CSS areas to the preserved
under the HLP. The removal of temporary fencing is only to
occur after all clearing and construction has been
completed.
Installation of temporary
fencing
Prior to project
grading
Applicant, Project
Biologist
The following project design
measure shall be carried
forward from the HLP
conditions to minimize
impacts to biological
resources and are identified
as mitigation measures for
the project. Implementation
of this mitigation measures
will be required as a
condition of project approval.
MM-BIO-C Lots adjacent to biological open space will
have permanent fencing and no gates between the
development and the open space; (a) landscaping will be
restricted to native and/or non-invasive plant species; and
(b) Best Management Practices (BMPs) during construction
in accordance with Nation Pollutant Discharge Elimination
Systems General Construction Permit requirements will be
implemented.
Installation of permanent
fencing between
development and open
space.
Implementation of BMPs
for water quality during
project construction.
Installation of
permanent fencing
prior to project
occupancy.
BMP
implementation is
during project
construction.
Applicant,
Contractor.
4.0 Mitigation Monitoring and Reporting Program
Heart of the City Specific Plan Amendment-Rancho Coronado 4-3 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Impact Mitigation Measure Action Timing Responsibility
The following project design
measure shall be carried
forward from the HLP
conditions to minimize
impacts to biological
resources and are identified
as mitigation measures for
the project. Implementation
of this mitigation measures
will be required as a
condition of project approval.
MM-BIO-D A biological monitor will be on-site when
habitat is being cleared, and/or construction activities are
occurring within 100 feet of a Biological Open Space
Easement boundary. Permanent signs must be placed every
100 feet along the fence bordering the preserve. The signs
must be corrosion resistant, no less than three feet above
the ground surface, have minimum dimensions of 6” x 9”,
and must state the following:
Sensitive Environmental Resources
Disturbance Beyond this point is Restricted
By Easement
Information:
Contact (Name of Conservancy)
Monitoring during
construction activities
and placement of
permanent signage along
boundary of
conservation area.
Signage shall be
placed prior to
project
construction.
Monitoring shall
occur during
project
construction.
Applicant, Project
Biologist
The following project design
measure shall be carried
forward from the HLP
conditions to minimize
impacts to biological
resources and are identified
as mitigation measures for
the project. Implementation
of this mitigation measures
will be required as a
condition of project approval.
MM-BIO-E A conservation easement shall be placed
over all on-site mitigation. Additionally, the applicant shall
insure that the biological open space is deeded to a nature
conservancy acceptable to the planning Division Director for
maintenance and monitoring purposes.
Recordation of a
conservation easement
over onsite mitigation
areas and deeding of
open space to a nature
conservancy.
Prior to issuance of
grading permit.
Owner/Applicant
and City.
The following project design
measure shall be carried
forward from the HLP
conditions to minimize
impacts to biological
resources and are identified
as mitigation measures for
the project. Implementation
of this mitigation measures
will be required as a
condition of project approval.
MM-BIO-F Manufactured slopes will be revegetated
with appropriate native species in consultation with the
Wildlife Agencies. The landscape plan and construction
documents will be approved by the City Engineer, Planning
Director, and Fire Marshal prior to issuance of building
permits.
Revegetation of
manufactured slopes
with native species.
Prior to issuance of
building permit.
Applicant, City
Engineer,
Planning Director
and Fire Marshal
and Wildlife
Agencies.
4.0 Mitigation Monitoring and Reporting Program
Heart of the City Specific Plan Amendment-Rancho Coronado 4-4 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Impact Mitigation Measure Action Timing Responsibility
The following project design
measure shall be carried
forward from the HLP
conditions to minimize
impacts to biological
resources and are identified
as mitigation measures for
the project. Implementation
of this mitigation measures
will be required as a
condition of project approval.
MM-BIO-G Any lands providing mitigation/
preservation for the project shall be held in perpetuity in
accordance with a habitat management plan to be approved
by the City and the Wildlife Agencies.
Preservation of land in
perpetuity.
Prior to issuance of
grading permit.
Owner/Applicant,
City and Wildlife
Agencies
Development of the project
will result in impact to
riparian habitats. This
represents a significant
impact.
MM-BIO-1A Impacts to 0.23 acre southern riparian
forest, 0.15 acre riparian woodland, 1.43 acres southern
willow scrub, 0.90 acre freshwater marsh, 0.33 acre mule fat
scrub, and 0.09 SWS/FWM habitat will be mitigated at a 3:1
ratio. Impacts to 0.85 acres disturbed wetland will be
mitigated at a 2:1 ratio. Impact to 0.02 acre streambed will
be mitigated at a 1:1 ratio as detailed in Table 7a for a total
of 8.89 acres of mitigation. Mitigation includes a
combination of onsite and offsite creation and enhancement
with 6.47 acres of creation and 0.30 acres of enhancement
occurring onsite and 1.27 acre creation mitigation credit
equivalents and 1.05 acres enhancement credits at the
North County Habitat Bank (NCHB).
Habitat creation both on
and offsite to meet the
required mitigation
amounts.
Prior to project
construction
Applicant, Project
Biologist
Impact to riparian habitats. MM-BIO-1B The preparation of a riparian restoration
plan will be required as a condition of the mitigation for
impacts to riparian vegetation communities. The plan will be
require review and approval by the City and include the
following.
• All final specifications and topographic-based
grading, planting, and irrigation plans (0.5-foot
contours and typical cross-sections) for the
creation/restoration sites. All wetland mitigation
areas shall be graded to the same elevation as
The preparation of a
riparian restoration plan
will be required as a
condition of the
mitigation for impacts to
riparian vegetation
communities.
Restoration plan
shall be prepared
and approved prior
to impact to
riparian habitats.
Applicant, Project
Biologist, City of
San Marcos
4.0 Mitigation Monitoring and Reporting Program
Heart of the City Specific Plan Amendment-Rancho Coronado 4-5 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Impact Mitigation Measure Action Timing Responsibility
adjacent existing jurisdictional wetlands areas,
and/or to within 1 foot of the groundwater table,
and shall be left in a rough grade state with micro
topographic relief (including channels for wetlands)
that mimics natural topography, as directed by the
City and Resource Agencies. All plantings shall be
installed in a way that mimics natural plant
distribution, and not in rows;
• Planting palettes (plant species, size, and
number/acre) and seed mix (plant species and
pounds/acre). Unless otherwise approved by the
City and Resource Agencies, only locally native
species (no cultivars) obtained from as close to the
project area as possible shall be used. The source
and proof of local nativeness of all plant material
and seed shall be provided;
• Container plant survival shall be 80 percent of the
initial plantings for the first year;
• A final implementation schedule that indicates
when all riparian/wetland impacts, as well as
riparian/wetland creation/restoration grading,
planting, and irrigation, will begin and end.
Necessary site preparation and planting shall be
completed during the concurrent or next planting
season (i.e., late fall to early spring). Any temporal
loss of habitat caused by delays in riparian/wetland
habitat creation/restoration shall be offset through
like habitat creation/restoration at a 0.5:1 ratio for
every 6 months of delay (i.e., 1:1 for 12 months
delay, 1.5:1 for 18 months delay, etc.). In the event
that the project applicant is wholly or partly
prevented from performing obligations under the
final plans (causing temporal losses due to delays)
because of unforeseeable circumstances or causes
beyond the reasonable control, and without the
fault of negligence of the project applicant,
4.0 Mitigation Monitoring and Reporting Program
Heart of the City Specific Plan Amendment-Rancho Coronado 4-6 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Impact Mitigation Measure Action Timing Responsibility
including but not limited to natural disasters (e.g.,
earthquakes, etc.), labor disputes, sudden actions
of the elements (e.g., further landslide activity), or
actions or inaction by federal or state agencies, or
other governments, the project applicant will be
excused by such unforeseeable cause(s);
• Five years of success criteria for wetland/riparian
creation/restoration areas, including separate
percent cover criteria for herbaceous understory,
shrub midstory, and tree overstory, and a total
percent absolute cover for all 3 layers at the end of
5 years; evidence of natural recruitment of multiple
species for all habitat types; 0 percent coverage for
Cal-IPC’s “Invasive Plant Inventory” species, and no
more than 10 percent coverage for other
exotic/weed species;
• A minimum of 5 years of maintenance and
monitoring of riparian/wetland creation/restoration
areas, unless success criteria are met earlier and all
artificial water supply has been off for at least 2
years
• A qualitative and quantitative vegetation
monitoring plan with a map of proposed sampling
locations. Photo points shall be used for qualitative
monitoring and stratified-random sampling shall be
used for all quantitative monitoring;
• Contingency measures in the event of
creation/restoration failure;
• ·Annual mitigation maintenance and monitoring
reports shall be submitted to the City and Resource
Agencies no later than December 1 of each year;
• A wetland delineation shall be done to confirm that
USACE and CDFW jurisdictional wetlands have been
successfully created/restored prior to final approval
of creation/restoration sites.
4.0 Mitigation Monitoring and Reporting Program
Heart of the City Specific Plan Amendment-Rancho Coronado 4-7 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Impact Mitigation Measure Action Timing Responsibility
Potential for impact to
species protected under the
Migratory Bird Treaty Act due
to project construction.
MM-BIO-2 Potential direct impacts to bird species
covered under the MBTA will be mitigated by restricting
brushing and grading to outside of the breeding season of
most bird species (general breeding season is February 15 to
August 31). Grubbing, grading, or clearing during the
breeding season of MBTA covered species could occur if it is
determined via a pre-construction survey that no nesting
birds (or birds displaying breeding or nesting behavior) are
present immediately prior to grubbing, grading, or clearing
and will require approval of the City that no breeding or
nesting avian species are present in the vicinity of the
grubbing, grading, or clearing. The City shall be notified of
any sensitive bird species identified during the pre-
construction surveys.
Avoidance of grubbing,
grading or clearing
during breeding season
or conduct a pre-
construction survey to
ensure there are no
breeding birds on site.
Avoidance of
grubbing, grading
or clearing between
the period of
February 15 to
August 31, or
conduct a pre-
construction survey
prior to
construction.
Applicant, Project
Biologist, City of
San Marcos
Potential for edge effects
from human activity adjacent
to biological open space lots.
MM-BIO-3 To reduce edge effects, on-site human
activity, and potential impacts related to the introduction of
exotic and domestic animals, the biological open space lots
shall be actively managed and monitored. The required
habitat management plan (as detailed in MM-BIO-1B) shall
ensure that access be restricted to developed areas.
Permanent fencing shall be provided for all backyards
abutting proposed project open space. In addition,
preserved habitat shall be posted with signs precluding
access due to habitat sensitivity and prohibiting dumping.
Residents shall be educated in access restrictions, control of
domestic animals, prevention of irrigation runoff, and
sensitivity of habitats on site.
Installation of permanent
fencing to restrict access
to developed areas.
Permanent fencing
prior to project
occupancy.
Residents shall be
notified of
restrictions upon
purchase of home.
Applicant, Project
Biologist
Potential for impact to
California gnatcatcher and
nesting raptors if grading or
clearing occurs during the
nesting season.
MM-BIO-4 If project grading (other than clearing and
grubbing of sensitive habitats) is necessary and adjacent to
preserved on-site habitat during the bird breeding season
(February 15 to August 31), a qualified biologist shall
conduct pre-construction surveys in the adjacent habitat for
the coastal California gnatcatcher\ and nesting raptors. The
survey shall begin not more than three days prior to the
beginning of grading activities. The Wildlife Agencies shall
Avoidance of grubbing,
grading or clearing
during breeding season
or conduct a pre-
construction survey to
ensure there are no
breeding birds on site.
Avoidance of
grubbing, grading
or clearing between
the period of
February 15 to
August 31, or
conduct a pre-
construction survey
Applicant, Project
Biologist, City of
San Marcos
4.0 Mitigation Monitoring and Reporting Program
Heart of the City Specific Plan Amendment-Rancho Coronado 4-8 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Impact Mitigation Measure Action Timing Responsibility
be notified if the gnatcatcher is observed nesting within 300
feet of proposed grading or if raptors are observed nesting
within 500 feet of proposed grading activities. No activities
which would result in noise levels exceeding 60 dBA hourly
Leq within this buffer shall be allowed. If grading activities
are not initiated prior to the breeding season, and any of
these species are present, and noise levels exceed this
threshold, noise barriers shall be erected to reduce noise
impacts to occupied habitat to below 60 dBA hourly Leq
and/or the activities shall be suspended. Impacts resulting
from noise for non-listed species other than raptors are not
considered significant, and mitigation is not warranted.
If birds are found on site,
noise levels shall be
curtailed to the level
noted in this mitigation
measures
prior to
construction.
Noise monitoring
during construction
if besting raptors or
CAGN are found
during the
preconstruction
surveys.
CULTURAL RESOURCES
Potential to encounter
unidentified cultural
resources during project
grading activities.
MM-CR-1 An archeological monitor and a Luiseño
Native American monitor shall be present during all earth
moving and grading activities to assure that any potential
cultural resources, including tribal, found during project
grading be protected.
Monitoring of
earthmoving and grading
activities.
During grading and
earthmoving
activity
Applicant,
Archaeological
Monitor, and
Tribal Monitor
MM CR-2 Prior to beginning project construction,
the Project Applicant shall retain a San Diego County
qualified archaeological monitor to monitor all ground-
disturbing activities in an effort to identify any unknown
archaeological resources. Any newly discovered cultural
resource deposits shall be subject to cultural resources
evaluation, which shall include archaeological
documentation, analysis and report generation.
Retention of an
archaeological monitor
to monitor ground
disturbing activities.
At least 30 days
prior to grading the
applicant shall
execute a Cultural
Resources and
Treatment
agreement with the
Applicant
MM-CR-3 At least 30 days prior to beginning project
construction, the Project Applicant shall enter into a Cultural
Resource Treatment and Monitoring Agreement (also known
as a pre-excavation agreement) with a Luiseño Tribe. The
Agreement shall address the treatment of known cultural
resources, the designation, responsibilities, and participation
of professional Native American Tribal monitors during
grading, excavation and ground disturbing activities; project
Development of a
Cultural Resources
Treatment and
Monitoring Agreement.
At least 30 days
prior to grading the
applicant shall
execute a Cultural
Resources and
Treatment
agreement with the
Applicant and
Rincon Band
4.0 Mitigation Monitoring and Reporting Program
Heart of the City Specific Plan Amendment-Rancho Coronado 4-9 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Impact Mitigation Measure Action Timing Responsibility
grading and development scheduling; terms of
compensation for the monitors; and treatment and final
disposition of any cultural resources, sacred sites, and
human remains discovered on site.
MM-CR-4 Prior to beginning project construction,
the Project Archaeologist shall file a pre-grading report with
the City to document the proposed methodology for grading
activity observation, which will be determined in
consultation with the Luiseño Tribe referenced in MM-CR-3. .
Said methodology shall include the requirement for a
qualified archaeological monitor to be present and to have
the authority to stop and redirect grading activities. In
accordance with the agreement required in MM-CR-3, the
archaeological monitor’s authority to stop and redirect
grading will be exercised in consultation with the Luiseño
Native American monitor in order to evaluate the
significance of any archaeological resources discovered on
the property. Tribal and archaeological monitors shall be
allowed to monitor all grading, excavation, and
groundbreaking activities, and shall also have the authority
to stop and redirect grading activities.
Filing of a pre-grading
report with the City.
Prior to project
construction.
Applicant
MM-CR-5 The landowner shall relinquish ownership
of all cultural resources collected during the grading
monitoring program and from any previous archaeological
studies or excavations on the project site to the appropriate
Tribe for proper treatment and disposition per the Cultural
Resource Treatment and Monitoring Agreement referenced
in MM-CR-3. All cultural materials that are deemed by the
Tribe to be associated with burial and/or funerary goods will
be repatriated to the Most Likely Descendant as determined
by the Native American Heritage Commission per California
Public Resources Code Section 5097.98.
In the event that curation of cultural resources is required,
curation shall be conducted by an approved facility and the
Landowner shall
relinquish any cultural
resources found on the
site to the appropriate
Tribe.
At the time
resources are
found.
Applicant
4.0 Mitigation Monitoring and Reporting Program
Heart of the City Specific Plan Amendment-Rancho Coronado 4-10 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Impact Mitigation Measure Action Timing Responsibility
curation shall be guided by California State Historic Resource
Commissions Guidelines for the Curation of Archaeological
Collections. The City of San Marcos shall provide the
developer final curation language and guidance on the
project grading plans prior to issuance of the grading permit,
if applicable, during project construction.
MM-CR-6 All sacred sites, should they be
encountered within the project area, shall be avoided and
preserved as the preferred mitigation, if feasible.
Avoidance and
preservation (if feasible)
of sacred sites
At the time of
encounter
Applicant
MM-CR-7 If human remains are encountered,
California Health and Safety Code Section 7050.5 states that
no further disturbance shall occur until the San Diego
County Coroner has made the necessary findings as to
origin. Further, pursuant to California Public Resources Code
Section 5097.98(b) remains shall be left in place and free
from disturbance until a final decision as to the treatment
and disposition has been made. Suspected Native American
remains shall be examined in the field and kept in a secure
location at the site If the San Diego County Coroner
determines the remains to be Native American, the Native
American Heritage Commission (NAHC) must be contacted
within 24 hours. The NAHC must them immediately notify
the “most likely descendant(s)” of receiving notification of
the discovery. The most likely descendants(s) shall then
make recommendations within 48 hours, and engage in
consultation concerning treatment of remains as provided in
Public Resources Code 5097.98,
Halting of construction
and contact NAHC.
At the time human
remains are
encountered
Applicant
MM-CR-8 If inadvertent discoveries of subsurface
archaeological/cultural resources are discovered during
grading, the Developer, the project archaeologist, and the
Luiseño Tribe under agreement with the landowner
described in MM-CR-3 shall assess the significance of such
resources and shall meet and confer regarding the
mitigation for such resources. Pursuant to California Public
Resources Code Section 21083.2(b) avoidance is the
Halt construction and
assess significance or
resources.
At the time
inadvertent
discoveries are
encountered
Applicant
4.0 Mitigation Monitoring and Reporting Program
Heart of the City Specific Plan Amendment-Rancho Coronado 4-11 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Impact Mitigation Measure Action Timing Responsibility
preferred method of preservation for archaeological
resources. If the Developer, the project archaeologist and
the Tribe cannot agree on the significance of mitigation for
such resources, these issues will be presented to the
Planning Director for decision. The Planning Director shall
make a determination based upon the provisions of the
California Environmental Quality Act with respect to
archaeological resources and shall take into account the
religious beliefs, customs, and practices of the Tribe.
Notwithstanding any other rights available under law, the
decision of the Planning Director shall be appealable to the
Planning Commission and/or City Council
HAZARDS/HAZARDOUS MATERIALS
Potential for impact due to
naturally-occurring arsenic on
the project site.
MM-HAZ-1
Prior to grading activities, the project applicant shall prepare
and implement a soils management plan that addresses
handling of soils containing naturally-occurring arsenic
during grading. The management plan shall be submitted to
the City Engineer for review and approval prior to the
issuance of a grading permit.
Prepare a Soils
Management Plan and
submit to the City.
Prior to grading Applicant and
City.
The project proposes
development adjacent to
natural areas which will be
preserved as open space. This
creates and areas where
development will be adjacent
to wildland areas that have a
high fire risk. This represents
a significant impact.
MM-HAZ-2 Prior to issuance of building permits, a fire
protection plan shall be prepared for the project and
submitted to the Planning Director and Fire Marshal for
review and approval. The fire protection plan shall include
fire fuel clearing and fire fuel management zones to provide
a minimum 150-foot buffer between proposed structures
and natural habitat. The fire protection plan shall identify
the responsible parties for the ongoing fire fuel maintenance
and the mechanism to ensure compliance with fire clearing
requirements. Implementation of the fire protection plan
shall be required prior project occupancy.
Preparation of fire
protection plan.
Prior to issuance of
building permit
Applicant and
City (Planning
Director and Fire
Marshal)
4.0 Mitigation Monitoring and Reporting Program
Heart of the City Specific Plan Amendment-Rancho Coronado 4-12 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Impact Mitigation Measure Action Timing Responsibility
NOISE
Onsite noise impacts due to
traffic for select homes.
MM-N-1 Sound barriers ranging from five to ten
feet shall be constructed to reduce future onsite noise levels
to be consistent with the Noise Element of the San Marcos
General Plan (60 dBA CNEL for single family and 65 dBA for
multifamily). Locations and heights of the proposed barriers
are presented in Figure 7, Noise Mitigation Measures.
Barriers could include berms, wall, glass or a combination of
these to meet the required noise attenuation.
Construction of noise
attenuation features
Prior to occupancy
of homes along the
west side of Las
Posas Road within
the project area.
Applicant
Potential for elevated interior
sound levels for select
homes.
MM-N-2 A final noise assessment shall be prepared
prior to the issuance of the first building permit. This final
report would identify the interior noise requirements based
upon architectural and building plans to meet the City’s
established interior noise limit of 45 dBA CNEL.
Conduct final noise
assessment and mitigate
noise conditions to
acceptable levels if an
exceedance is identified
Prior to issuance of
first building
permit.
Applicant
Potential for elevated
exterior noise levels on the
non-residential mixed use
portion of the project site.
MM-N-3 If outdoor usable areas are proposed in
the non-residential mixed use areas of the project, the
design shall consider shielding form the buildings, increased
setbacks from the roadways or conduct a site specific noise
study to determine compliance. An interior noise
assessment is required to mitigate the exterior noise levels
to an interior level of 50 dBA CNEL. This report should be
conducted prior to the issuance of building permits and
would finalize the noise requirements based upon actual
building design specifications.
Conduct final noise
assessment and mitigate
noise conditions to
acceptable levels if an
exceedance is identified
Prior to issuance of
first building
permit.
Applicant
Potential for noise impacts
during rock crushing.
MM-N-4 If rock crushing is proposed, upon starting
of crushing operations, noise measurements of the rock
crushing facility shall be required to ensure compliance with
the City’s thresholds. If noise levels are found to be above
the established thresholds of 60 dBA at any existing single
family residential use, 65 dBA for any multifamily use or 70
dBA at a commercial use then additional mitigation in the
form of berms or temporary walls will need to be
incorporated into the rock crusher design to reduce the
noise levels to below the City’s thresholds.
Take noise
measurements if two
crushers will be operated
simultaneously. If noise
levels exceed thresholds,
implement noise
reduction measure to
meet noise standards.
During rock
crushing phase.
Applicant
4.0 Mitigation Monitoring and Reporting Program
Heart of the City Specific Plan Amendment-Rancho Coronado 4-13 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Impact Mitigation Measure Action Timing Responsibility
TRAFFIC AND CIRCULATION
The addition of project-
related traffic results in a
significant impact at the
intersection of Twin Oaks
Valley Road / SR-78
Eastbound Ramps Grand
Avenue/ SR-78 EB Ramps –
Via Vera Cruz in the Horizon
Year 2030 Peak Hour
Intersection Condition. This
represents a significant
impact.
MM-TR-1 The project applicant shall make a fair
share contribution towards the following improvements at
the Twin Oaks Valley Road/SR-78 Eastbound Ramps:
• Construct an additional dedicated right-turn lane at
eastbound (off-ramp) approach of intersection.
• Restripe eastbound approach to include one left-
turn lane, one shared left-turn/through/right-turn
lane, and two right-turn lanes.
Payment of a fair share
contribution for future
improvements at this
intersection.
Prior to issuance of
building permits.
Applicant
The addition of project-
related traffic results in a
significant impact at the
intersection of Twin Oaks
Valley Road/Discover Street-
Barham Drive in the Horizon
Year 2030 Peak Hour
Intersection Condition. This
represents a significant
impact.
MM-TR-2 The project applicant shall make a fair
share contribution towards the widening of the northbound
approach of the Twin Oaks Valley Road/Discover Street-
Barham Drive intersection to construct a dedicated right-
turn lane.
Payment of a fair share
contribution for future
improvements at the
northbound approach of
the Twin Oaks Valley
Road/Discover Street-
Barham Drive
intersection
Prior to issuance of
building permits.
Applicant
4.0 Mitigation Monitoring and Reporting Program
Heart of the City Specific Plan Amendment-Rancho Coronado 4-14 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
Table 4-2. Design Considerations for the Project
Air Quality
• The project shall implement dust control measures. These measures include watering of active grading
sites and unpaved roads a minimum of twice daily, replacement of ground cover as quickly as possible,
reducing speeds on unpaved roads/surfaces to 15 miles per hour or less, and reducing dust during
unloading and loading operations.
• Low-VOC coatings shall be used for all buildings, as required under SDAPCD Rule 67.0.
Biological Resources
• No invasive plant species shall be in the landscaping plans, and no species on the Cal-IPC “Invasive Plant
Inventory” list shall be included in the erosion control plan.
• All exterior lighting adjacent to preserved habitat including street lighting for Street A shall be limited to
low pressure sodium sources of the lowest illumination allowed for human safety, selectively placed,
shielded, and directed away from preserved habitat to the maximum extent practicable.
• Inspection of all plant material for Argentine ants prior to use on the site.
• The monitoring biologist shall periodically monitor adjacent habitats for excessive amounts of dust, and
recommend remedial measures to address dust control if necessary.
Geology/Soils
• The project shall implement Best Management Practices (BMPs) to minimize sedimentation or other soil
impacts during project construction. BMPs could includes some or all of these strategies: erosion bale,
silt fencing, storm drain inlet protection, outlet protection, stabilized construction entrance, brush
barrier, sandbag barrier, waste disposal and proper siting of equipment fueling.
Noise – Grading/Construction
• All equipment construction equipment shall be properly fitted with mufflers.
• All equipment staging and maintenance shall be conducted as far away from existing residences as
possible.
• All construction equipment staging and maintenance should be conducted as far away for the existing
residence as possible.
• Haul truck speed limit of 15 miles per hour shall be posted along the on-site haul route and include
signage limiting the use of engine “jake” brakes.
Noise – Blasting
• The general contractor or property owner/developer shall give reasonable notice in writing at the time
of issuance of a building permit, grading permit or encroachment license to all residences or businesses
within 600 feet of any potential blast location. The notice shall be in a form approved by the Building
Director. Any resident or business receiving such notice may request of the Building Director that a
notice of impending blasting be given by the blaster at the time of the 12 hour advance notice given to
the Building Director. The general contractor or property owner/developer shall make all reasonable
efforts to contact any and all parties requesting the second notice.
• The blaster shall file a written certification with the Building Director certifying that the general notice
required by Section 17.60.060(b) has been given. The certificate shall include addresses and date(s) of
notification. A copy shall be retained on file at the Building Division.
• Inspections of all structures within 300 feet of the blast site shall be made before blasting operations.
The persons inspecting shall obtain the permission of the building owner to conduct an inspection. The
inspections shall be done by a registered structural engineer employed by the blaster or project
4.0 Mitigation Monitoring and Reporting Program
Heart of the City Specific Plan Amendment-Rancho Coronado 4-15 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
contractor. The inspection shall be only for the purpose of determining the existence of any visible or
reasonably recognizable pre-existing defects or damages in any structure. Inspection refusal shall be at
the discretion of the property owner.
• Blasting shall only be permitted between the hours of 9:00 a.m. and 4:00 p.m. during any weekday,
Monday through Friday, exclusive of City recognized holidays unless special circumstances warrant
another time or day and special approval is granted by the Building Director and Fire Chief.
Public Services – Fire
• Roadways serving the project shall have a minimum improved paved width of 24 feet with an additional
8 feet to each side for parking. Any deviations from this or any other roadway features such as cul-de-
sacs and gates must meet the design criteria of the San Marcos Fire Department.
• Any automatic gates are required to have a Knox rapid entry system and emergency vehicle strobe
detector.
• Fire hydrants with an adequate water supply must be installed at locations approved by the San Marcos
Fire Department. Hydrant spacing shall be 300 feet apart.
• Residential structures shall be fire sprinklered per California Building Code 2010 edition and city
ordinance.
• Homes and mixed use buildings will be required to be designed using state fire marshal standards for
fire resistive construction features using the California Building Code 2013 edition Chapter 7, design to
be reviewed by City Building Department.
• A 150-foot wildland fuel modification is required from all sides of all structures.
Utilities and Service Systems
• Upsize 2,700 feet of existing 8-inch wastewater collection pipe in Craven Road. This segment is located
between Santa Barbara Drive and a point approximately 575 feet south of Discovery Street. The
improvement includes 700 feet of 10-inch pipeline and 2,000 feet of 12-inch pipeline.
• Installation of a new 14-inch diameter water main loop from the intersection of Twin Oaks Valley Road
and South Village Drive to the existing 14-inch water main, approximately 1,100 feet north of South Lake
Pump Station.
• Payment of Water Capital Facility Fees per Vallecitos Water District Ordinance No. 175.
• Payment of Wastewater Capital Facility Fees per Vallecitos Water District Ordinance No. 176.
• Payment of Wastewater Density Impact Fees per Vallecitos Water District Ordinance No. 177.
Water Quality
During construction, measures would be implemented as part of the project to control erosion, sedimentation,
and pollution that could impact water resources on and off site. Prior to the commencement of grading, a Notice
of Intent must be filed with the Regional Water Quality Board for a National Pollutant Discharge Elimination
System (NPDES) General Construction Storm Water Permit. Specific permit requirements include
implementation of an approved Storm Water Pollution Prevention Plan, which requires best management
practices for erosion and sediment control related to construction activities. Standard measures that may apply
to the proposed project include:
• Surface drainage will be designed to collect and move runoff into adequately sized drainage structures
before being discharged into natural stream channels.
• Erosion control measures associated with the project will include techniques for both long- and short-
term erosion hazards. These include such measures as the short-term use of gravel bags, matting,
mulches, berms, hay bales, or similar devices along all pertinent graded areas to minimize sediment
transport.
• Native vegetation will be preserved whenever feasible, and all disturbed areas will be stabilized as soon
as possible after completion of grading.
4.0 Mitigation Monitoring and Reporting Program
Heart of the City Specific Plan Amendment-Rancho Coronado 4-16 City of San Marcos
Final Initial Study/Mitigated Negative Declaration April 2014
• Use of energy dissipating structures (e.g., detention ponds, riprap, or drop structures) will be used at
storm drain outlets, drainage crossings, and/or downstream of all culverts, pipe outlets, and brow
ditches to reduce velocity and prevent erosion.
• A maintenance plan for temporary erosion control facilities will be established. This typically involves
inspection, cleaning, and repair operations being conducted after runoff-producing rainfall.
• Removal and disposal of ground water (if any) encountered during construction activities will be
coordinated with the RWQCB to ensure proper disposal methods and locations under a General
Dewatering Permit if required. This may involve specific measures such as removing excess sediment
(through the use of desilting basins, etc.) and limiting discharge velocity.
• Specified fueling and maintenance procedures will be designated to preclude the discharge of hazardous
materials used during construction (e.g., fuels, lubricants, and solvents). Such designations will include
specific measures to preclude spill including proper handling and disposal techniques.
Per the project’s Water Quality Improvement Plan, the following Source Control BMPs are proposed:
• Mark all inlets with the words “No Dumping! Flows to Bay” or similar language.
• Landscaping is designed to minimize irrigation and runoff and to minimize the use of fertilizers and
pesticides that can contribute to stormwater pollution
• Landscaping in the bio-retention areas shall use California drought tolerant native grasses
• Plaza, sidewalks and parking lots shall be swept regularly to prevent the accumulation of litter and
debris.
The project is required to comply with the latest NPDES permit (Order No. R9-2013-0001) and latest City of San
Marcos Storm Water Standards Manual guidelines. The WQIP shall be approved by the City prior to issuance of
any grading permit and shall address Low Impact Development standards and hydromodification.
Heart of the City Specific Plan Amendment (Rancho Coronado) i City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
TABLE OF CONTENTS
I. INTRODUCTION ..................................................................................................................... 1
II. PROJECT DESCRIPTION ........................................................................................................... 4
III. ENVIRONMENTAL CHECKLIST ............................................................................................... 12
A. BACKGROUND ................................................................................................................... 14
B. ENVIRONMENTAL FACTORS POTENTIALLY AFFECTED ...................................................... 15
C. DETERMINATION .............................................................................................................. 15
IV. ENVIRONMENTAL ANALYSIS ................................................................................................. 24
I. AESTHETICS ....................................................................................................................... 24
II. AGRICULTURE AND FOREST RESOURCES .......................................................................... 26
III. AIR QUALITY ...................................................................................................................... 27
IV. BIOLOGICAL RESOURCES ................................................................................................... 38
V. CULTURAL RESOURCES ..................................................................................................... 50
VI. GEOLOGY AND SOILS ......................................................................................................... 54
VII. GREENHOUSE GAS EMISSIONS .......................................................................................... 56
VIII. HAZARDS AND HAZARDOUS MATERIALS .......................................................................... 61
IX. HYDROLOGY AND WATER QUALITY .................................................................................. 65
XI. MINERAL RESOURCES ....................................................................................................... 65
XII. NOISE ................................................................................................................................ 74
XIII. POPULATION AND HOUSING ............................................................................................ 90
XIV. PUBLIC SERVICES ............................................................................................................... 91
XV. RECREATION...................................................................................................................... 93
XVI. TRANSPORTATION/TRAFFIC.............................................................................................. 94
XVII. UTILITIES AND SERVICE SYSTEMS .................................................................................... 123
V MANDATORY FINDINGS OF SIGNIFICANCE .......................................................................... 130
VI. PERSONS AND ORGANIZATIONS CONSULTED ...................................................................... 133
VII. REFERENCES ...................................................................................................................... 134
VIII. MITIGATED NEGATIVE DECLARATION ................................................................................. 136
IX. FINDINGS ........................................................................................................................... 137
Heart of the City Specific Plan Amendment (Rancho Coronado) ii City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
LIST OF APPENDICES (Appendices included on CD in back of document)
Appendix A.1 Tentative Map
Appendix A.2 Amended Heart of the City Specific Plan
Appendix A.3 Draft Rancho Coronado Residential Design Guidelines
Appendix B Air Quality Report
Appendix C Biological Technical Report
Appendix D Cultural Resources Report
Appendix E Geotechnical Report
Appendix F Global Climate Change Report
Appendix G Draft Phase I Environmental Site Assessment
Appendix H Additional Soil Characterization Report
Appendix I Water Quality Improvement Plans
Appendix J Breach Study and Inundation Map
Appendix K Noise Report
Appendix L Police, Fire and School Letters
Appendix M Traffic Analysis
Appendix N Water and Sewer Study
Appendix O Least Bell’s Vireo Survey Report
LIST OF FIGURES
Figure 1. Project Location and Vicinity .............................................................................................. 5
Figure 2. Proposed Project ................................................................................................................. 6
Figure 3. Rancho Coronado Residential Development Areas ............................................................ 7
Figure 4. Proposed Spillway Channel Cross Section .......................................................................... 8
Figure 5. Ambient Noise Monitoring Locations ............................................................................... 76
Figure 6. Modeled Receptor Locations ............................................................................................ 77
Figure 7. Noise Mitigation Measures – Barrier Height and Locations ............................................. 79
Figure 8. Rock Crusher Noise Contour ............................................................................................. 89
Heart of the City Specific Plan Amendment (Rancho Coronado) iii City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
LIST OF TABLES
Table 1. Rancho Coronado Residential Development Standards ..................................................... 7
Table 2. Design Considerations for the Project .............................................................................. 10
Table 3. Attainment Status of Criteria Pollutants in San Diego Air Basin ....................................... 28
Table 4. Screening-Level Criteria for Air Quality Impacts ............................................................... 29
Table 5a. Construction Emissions – Proposed Project ..................................................................... 31
Table 5b. Operational Emissions – Proposed Project ....................................................................... 34
Table 6. CO Hot Spot Evaluation – Predicted CO Concentrations, ppm ......................................... 36
Table 7a. Mitigation Requirements for Rancho Coronado (acres) ................................................... 41
Table 7b. Summary of Impact to Vegetation Communities ............................................................. 46
Table 8. USACE and CDFW Jurisdictional Impacts .......................................................................... 49
Table 9a. Summary of Estimated Operational GHG Emission – Business as Usual Scenario ........... 58
Table 9b. Summary of Estimated Operational GHG Emission – With GHG Reduction
Measures Scenario ............................................................................................................ 59
Table 10. Measured Ambient Noise Levels ...................................................................................... 75
Table 11. Future Traffic Parameters ................................................................................................. 75
Table 12. Future Exterior Noise Levels ............................................................................................. 78
Table 13. Vibration Levels from Construction Activities (Residential Receptors) ............................ 81
Table 14. Existing Roadway Noise Levels ......................................................................................... 83
Table 15. Existing + Project Roadway Noise Levels .......................................................................... 84
Table 16. Existing vs. Existing + Project Roadway Noise Levels ........................................................ 84
Table 17. Existing + Project + 2030 Cumulative Roadway Noise Levels ........................................... 85
Table 18. Existing vs. Existing + Project + 2030 Cumulative Roadway Noise Levels ........................ 86
Table 19. Construction Noise Levels ................................................................................................. 88
Table 20. Rock Crushing Noise Levels ............................................................................................... 89
Table 21. Existing Peak Hour Intersection Conditions ...................................................................... 95
Table 22. Existing Daily Roadway Segment Conditions .................................................................... 95
Table 23. Proposed Project Trip Generation .................................................................................... 96
Table 24. Existing Plus Project Peak Hour Intersection Conditions .................................................. 97
Table 25. Existing Plus Project Daily Roadway Segment Conditions ................................................ 98
Table 26. Year 2016 Cumulative Peak Hour Intersection Conditions - Without and With
Project ............................................................................................................................... 99
Table 27. Year 2016 Cumulative Daily Roadway Segment Conditions - Without and With
Project ............................................................................................................................. 100
Table 28. Year 2020 Cumulative Peak Hour Intersection Conditions Without and With
Project ............................................................................................................................. 102
Table 29. Year 2020 Cumulative Daily Roadway Segment Conditions - Without and With
Project ............................................................................................................................. 103
Table 30. Horizon Year 2030 Peak Hour Intersection Conditions - Without and With
Project ............................................................................................................................. 104
Table 31. Horizon Year 2030 Daily Roadway Segment Conditions - Without and With
Project ............................................................................................................................. 106
Table 32. Caltrans ILV Analysis ....................................................................................................... 108
Table 33. Peak Hour Freeway Segment Analysis Existing / Existing Plus Project Conditions ......... 108
Table 34. Peak Hour Freeway Segment Analysis Year 2016 Cumulative Conditions ..................... 110
Table 35. Peak Hour Freeway Segment Analysis Year 2020 Cumulative Conditions ..................... 112
Table 36. Peak Hour Freeway Segment Analysis Horizon Year 2030 Conditions ........................... 113
Heart of the City Specific Plan Amendment (Rancho Coronado) iv City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
LIST OF TABLES (Continued)
Table 37. Peak Hour Freeway Ramp Metering Analysis ................................................................. 115
Table 38. Peak Hour Intersection Queuing Analysis Twin Oaks Valley Road / SR-78 Eastbound
Ramps (Existing / Existing Plus Project Conditions) ........................................................ 117
Table 39. Peak Hour Intersection Queuing Analysis Twin Oaks Valley Road / SR-78 Eastbound
Ramps (Year 2016 / Year 2020 Cumulative Conditions) ................................................. 118
Table 40. Peak Hour Intersection Queuing Analysis Twin Oaks Valley Road / SR-78 Eastbound
Ramps (Horizon Year 2030 Conditions) .......................................................................... 119
Table 41. Rancho Coronado Estimated Water Demand ................................................................. 125
Table 42. Rancho Coronado Estimated Wastewater Flows ........................................................... 125
Heart of the City Specific Plan Amendment (Rancho Coronado) 1 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
I. INTRODUCTION
A. PURPOSE
This document is an Initial Study (IS) for preliminary evaluation of environmental impacts resulting from
implementation of the Heart of the City Specific Plan Amendment for the Rancho Coronado project. For
the purposes of this document, this proposed development as described in Section II, Project
Description, will be called the “proposed project.”
B. CALIFORNIA ENVIRONMENTAL QUALITY ACT REQUIREMENTS
As defined by Section 15063 of the State of California Environmental Quality Act (CEQA) Guidelines, an
IS is prepared to provide the Lead Agency with information to use in deciding to prepare either an
Environmental Impact Report (EIR) or a Negative Declaration (ND) as the most appropriate
environmental documentation for the proposed discretionary action. The City of San Marcos (City) is
designated the Lead Agency, in accordance with Section 15050 of the CEQA Guidelines. The Lead Agency
is the public agency with the principal responsibility for approving a project that may have significant
effects upon the environment.
Through this IS, the City has determined that although the project could have a significant effect on the
environment, mitigation has been included to bring all potential impacts to less than significant levels.
This determination was made based upon technical analysis, factual data, and other supporting
documentation. Therefore, a Mitigated Negative Declaration (MND) is being proposed. The IS/MND will
be circulated for a period of 30 days for public and agency review. Comments received on the document
will be considered by the City before it acts on the proposed project.
This IS has been prepared in conformance with CEQA of 1970, as amended (Public Resources Code,
Section 21000 et. seq.) and Section 15070 of the State Guidelines for Implementation of CEQA of 1970,
as amended (California Code of Regulations, Title 14, Chapter 3, Section 15000, et seq.).
C. INTENDED USES OF INITIAL STUDY/MITIGATED NEGATIVE DECLARATION
This IS, along with the attached MND, is an informational document intended to inform City decision-
makers, other responsible or interested agencies, and the public of potential environmental effects of
the proposed project. The environmental review process has been established to enable public agencies
to evaluate environmental consequences and to examine and implement methods of eliminating or
reducing any potentially adverse impacts.
D. CONTENTS OF DOCUMENT
This IS/MND is organized to facilitate a basic understanding of the existing setting and environmental
implications of the proposed project as follows:
I. INTRODUCTION identifies the City contact persons involved in the process, scope of
environmental review, environmental procedures, and incorporation by reference documents.
Heart of the City Specific Plan Amendment (Rancho Coronado) 2 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
II. PROJECT DESCRIPTION describes the proposed project. A description of proposed discretionary
approvals and permits required for project implementation is also included.
III. ENVIRONMENTAL CHECKLIST FORM presents the results of the environmental evaluation for the
proposed project and those issue areas that would have a significant impact, potentially significant
impact, a less than significant impact with mitigation incorporation, or no impact.
IV. ENVIRONMENTAL ANALYSIS evaluates each response provided in the environmental checklist
form. Each response checked is discussed and supported with sufficient data and analysis. As
appropriate, each response discussion describes and identifies specific impacts anticipated with
project implementation. In this section, mitigation measures are also recommended, as appropriate,
to reduce adverse impacts to levels of “less than significant” where possible.
V. MANDATORY FINDINGS presents Mandatory Findings of Significance in accordance with Section
15065 of the CEQA Guidelines.
VI. PERSONS AND ORGANIZATIONS CONSULTED identifies those persons consulted and involved in
preparation of this IS.
VII. REFERENCES lists bibliographical materials used in preparation of this document.
VII. MITIGATED NEGATIVE DECLARATION
E. SCOPE OF ENVIRONMENTAL ANALYSIS
For evaluation of environmental impacts, each question from the Environmental Checklist Form is stated
and responses are provided according to the analysis undertaken as part of the Initial Study. All
responses take into account the whole action involved, including off-site as well as on-site, cumulative
as well as project-level, indirect as well as direct, and construction as well as operational impacts.
Project impacts and effects will be evaluated and quantified, when appropriate. To each question, there
are four possible responses, including:
1. No Impact: A “No Impact” response is adequately supported if the referenced information
sources show that the impact simply does not apply to the proposed project.
2. Less Than Significant Impact: Development associated with project implementation will have
the potential to impact the environment. These impacts, however, will be less than the levels of
thresholds that are considered significant and no additional analysis is required.
3. Less Than Significant With Mitigation Incorporated: This applies where incorporation of
mitigation measures has reduced an effect from “Potentially Significant Impact” to a “Less Than
Significant Impact.” The Lead Agency must describe the mitigation measures and explain how
the measures reduce the effect to a less than significant level.
4. Potentially Significant Impact: Future implementation will have impacts that are considered
significant and additional analysis and possibly an EIR are required to identify mitigation
measures that could reduce these impacts to less than significant levels.
Heart of the City Specific Plan Amendment (Rancho Coronado) 3 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
F. PERMITS AND ENTITLEMENTS FOR PROJECT APPROVAL
Agency Discretionary Action
City of San Marcos • Adoption of Specific Plan (SP 13-006)
• Tentative Subdivision Map (TSM 13-004)
• Adoption of Mitigated Negative Declaration
(ND-14-001)
• Adoption of Mitigation Monitoring and
Reporting Program Project Approval
California Department of Fish and Game Section 1600 Streambed Alteration Agreement
Regional Water Quality Control Board Section 401 Water Quality Certification
U.S. Army Corps of Engineers Section 404 Permit
Additionally, the following ministerial approvals will be required for the project: Grading Permit,
Landscaping Permit, and Building Permit.
Heart of the City Specific Plan Amendment (Rancho Coronado) 4 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
II. PROJECT DESCRIPTION
A. PROJECT LOCATION AND SETTING
The project is located within the southwestern portion of the Heart of the City Specific Plan (HOCSP).
The 248-acre project site property is bounded by Twin Oaks Valley Road on the east, the Discovery Hills
residential community on the north, and undeveloped land on the west and south in the
Barham/Discovery Hills neighborhood (Figure 1).
The project site sits within the boundaries of the former Hanson mining site. The eastern and northern
portions of the former Hanson mining site are disturbed from past aggregate mining activities and the
remainder of the site contains undeveloped native habitat. All upland habitat impacts associated with
the mining and the current residential project have been previously analyzed within the approved
Habitat Loss Permit (HLP; HLP 03-08) approved by the City on December 23, 2003 and approved by the
Wildlife Agencies on January 23, 2004. The project development is proposed in areas that are disturbed
from previous mining and cleared following the initial HLP approval.
B. PROJECT DESCRIPTION
The project proposes a Specific Plan Amendment (SPA) to the HOCSP. The project area covers 248 acres
within the HOCSP. The project would develop residential, non-residential mixed use, and active park
uses consistent with the General Plan. The project also preserves open space. Figure 2 shows the
planning areas of the HOCSP that are part of the proposed project (circled in red). The proposed
Tentative Map, Specific Plan Amendment, and Rancho Coronado Residential Design Guidelines are
included as Appendices A.1, A.2, and A.3.
Residential – The project would allow for up to 346 high-efficiency single family homes on
approximately 58 acres. Product types include front-loaded and alley-loaded single family detached, as
well as alley-loaded paired (duplex) and alley-loaded courtyard homes. Residential development is
proposed four areas (Area A, B, C and D), as detailed in Figure 3. The developments standards for each
of the residential areas are presented in Table 1.
Mixed Use (Non-Residential) – The project includes 22.24 acres of MU-4 (non residential mixed use) in
the southern portion of the project site, adjacent to Twin Oaks Valley Road. Allowable uses under this
designation include commercial, office professional, and office and business park uses. These uses may
be mixed vertically (on separate floors of a building) or horizontally (on a single site or adjacent parcel).
While specific development is not proposed within this area at this time, the environmental analysis
assume 90 percent of the MU-4 area would be developed with business park uses and the remaining 10
percent would be retail with a total of 240,000 s.f. developed on the 22.24 acres.
Park – Grading of 38.43 acres is proposed as a future active use City park. Anticipated uses include
active park uses, lighted ball fields, and associated parking.1
1 A park plan is not analyzed at this time, however, traffic generated by a future park, as well as air quality and noise associated
with the traffic, is considered in this analysis. At the time a park plan is proposed in the future, the project would be subject to
additional CEQA review.
Heart of the City Specific Plan Amendment (Rancho Coronado) 5 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Figure 1. Project Location and Vicinity
Heart of the City Specific Plan Amendment (Rancho Coronado) 6 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Figure 2. Proposed Project
Heart of the City Specific Plan Amendment (Rancho Coronado) 7 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Figure 3. Rancho Coronado Residential Development Areas
Table 1. Rancho Coronado Residential Development Standards
Residential Area A B C D
Configuration Front-loaded Single
Family Dwelling
Alley-loaded Single
Family Dwelling
Alley-loaded
Paired
Alley-loaded
Courtyard
Max. Dwelling Units 72 units 54 units 72 units 148 units
Minimum Lot Area(1)
3,910 SF 2,880 SF 2,440 SF 1,840 SF
Minimum Front Setback
from Sidewalk
10 feet 10 feet 10 feet 10 feet
Minimum Front Setback
from Paseo
N/A N/A 10 feet(3)
7.5 feet(4)
Minimum Side Setback
from Sidewalks
10 feet 10 feet 10 feet 10 feet
Minimum Side Setback
from Property Line
5 feet 5 feet 5 feet 5 feet
Minimum Front Garage
Setback from Sidewalk
16 feet/18 feet(2)
N/A N/A N/A
Minimum Rear Setback
from Property Line
16 feet/18 feet(2)
N/A N/A N/A
Minimum Rear Setback
from Back of Alley Curb
15 feet 3 feet 3 feet 3 feet
Height Limit 35 feet 35 feet 35 feet 35 feet
Notes:
(1) The Lot Area is measured from back of sidewalk and from back of private alley curb, where applicable.
(2) The front yard setback is 16 feet for the garage façade and 18 feet for the garage door
(3) Setback measured from edge of Paseo
(4) Setback measured from centerline of Paseo
Heart of the City Specific Plan Amendment (Rancho Coronado) 8 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Preserved Open Space – The project includes approximately 129.29 acres of preserved open space. This
includes preserved upland habitat in accordance with the approved Habitat Loss Permit, as well as
riparian areas that will be created and/or enhanced and then added to the open space easement.
Spillway Conveyance Channel – The project includes the construction of a temporary channel extension
in the southern portion of the project site to convey the spillway drainage. See Figure 4 for a cross
section of the channel and the general location within the project site. The channel would be 5 feet wide
and 5 feet deep with a 2:1 bank. The channel would be lined with half-ton rip rap on one inch of gravel
over a sand filter bank. The channel would be approximately 900 feet in length. At the time the non-
residential mixed use portion of the site is developed, a refined design to handle spillway overflow will
be developed. That final design would be subject to additional CEQA review.
Figure 4. Proposed Spillway Channel Cross Section
Roadway and Pedestrian Improvements – The proposed project includes the extension of North Village
Drive “Street B”(600 lineal feet) west of Twin Oaks Valley and Street “A” (Backbone Road, 4,400 lineal
feet) which will connect Santa Barbara Drive to the north with Twin Oaks Valley Road to the east. These
two public streets will be constructed with curb, gutter, sidewalk-trail, and landscaping. Curb to curb
widths will vary from 30 to 38 feet. The proposed private roadways range from 38 to 25 feet in paved
width, with additional width for curb, gutter, sidewalks or walking paths. A trail linkage from South Lake
Park to the project site will also be included.
Utilities – The project site is within the Vallecitos Water District (VWD) boundary and is eligible for water
service. The project site is not within VWD’s sewer district boundaries and the entire project site must
be annexed to be eligible for sewer service. This is an intra-district annexation and does not require
Local Agency Formation Commission (LAFCO) approval or process.
Heart of the City Specific Plan Amendment (Rancho Coronado) 9 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
The project includes the necessary utility improvements to support the proposed development and
includes approximately 15,360 linear feet of water lines and 14,000 linear feet of sewer lines. The
project would connect to existing Vallecitos Water District (VWD) infrastructure for water and sewer
services.
Offsite sewer extensions within Santa Barbara Drive and Twin Oaks Valley Road would also be required.
The project will also be required to upsize approximately 2,700 feet of an existing 8-inch wastewater
collection pipe in Craven Road. This segment is located between Santa Barbara Drive and a spot
approximately 575 feet south of Discovery Street. The improvement includes 700 feet of 10-inch
pipeline and 2,000 feet of 12-inch pipeline. The project will also relocate an existing 14-inch Vallecitos
Water District water main. Finally, any existing gas, electric, or communication lines (dry utilities) will be
abandoned or relocated. New dry utility lines will be constructed to serve the project.
An existing VWD access road to South Lake Dam and the existing VWD pump station in the southern
portion of the project will be relocated within the project site in a manner that is acceptable to VWD.
Water Quality Management – The project includes a comprehensive water quality management
approach. The project proposes self-treating areas, nine bio retention basins covering over 2.5 acres and
additional best management practices (BMPs) for onsite public roads. The use of construction-related
and source control BMPs which will further minimize the addition of pollutants and debris into the
drainage system. The project includes approximately 11,198 linear feet of storm drains.
Grading – Grading for the project includes 2,608,200 cubic yards (cy) of cut and 2,853,800 cy of fill and
will balance onsite assuming a 15 to 18 percent bulking factor. This includes the 1,800 cy needed to
excavate for the spillway conveyance. No offsite export or import will be required for the project. Due to
underlying bedrock conditions blasting will be required as part of the project construction. Additionally a
rock crusher may be required for the project as well.
Project Phasing - Project phasing will include an overall grading phase commencing in 2014. The grading
phase would include blasting and rock crushing. Phase 1 construction will start in 2015 and is
anticipated to be completed by late 2016 or early 2017. Phase 1 includes Residential Areas A and B (126
dwelling units), Backbone Road (Street “A”) from Santa Barbara Drive to North Village Drive, and North
Village Drive (Street “B”) extended west to the Backbone Road.
Phase 2 construction is anticipated to start in 2017 and be complete by 2020. Phase 2 includes
construction of 220 dwelling units in Residential Areas C and D; construction of the non-residential
mixed-use portion of the project, which will include 90 percent business park and 10 percent retail;
construction of a 38.43 acre active park; construction of Backbone Road from North Village Drive to
South Village Drive; construction of South Village Drive extended west to Backbone Road; installation of
a new signal for access to the mixed use site, and construction of the access road for the mixed use site.
Finally, the project includes design considerations and will adhere to applicable regulatory
requirements, as identified in Table 2.
Heart of the City Specific Plan Amendment (Rancho Coronado) 10 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 2. Design Considerations for the Project
Air Quality
• The project shall implement dust control measures. These measures include watering of active grading
sites and unpaved roads a minimum of twice daily, replacement of ground cover as quickly as possible,
reducing speeds on unpaved roads/surfaces to 15 miles per hour or less, and reducing dust during
unloading and loading operations.
• Low-VOC coatings shall be used for all buildings, as required under SDAPCD Rule 67.0.
Biological Resources
• No invasive plant species shall be in the landscaping plans, and no species on the Cal-IPC “Invasive Plant
Inventory” list shall be included in the erosion control plan.
• All exterior lighting adjacent to preserved habitat including street lighting for Street A shall be limited to
low pressure sodium sources of the lowest illumination allowed for human safety, selectively placed,
shielded, and directed away from preserved habitat to the maximum extent practicable.
• Inspection of all plant material for Argentine ants prior to use on the site.
• The monitoring biologist shall periodically monitor adjacent habitats for excessive amounts of dust, and
recommend remedial measures to address dust control if necessary.
Geology/Soils
• The project shall implement Best Management Practices (BMPs) to minimize sedimentation or other soil
impacts during project construction. BMPs could includes some or all of these strategies: erosion bale,
silt fencing, storm drain inlet protection, outlet protection, stabilized construction entrance, brush
barrier, sandbag barrier, waste disposal and proper siting of equipment fueling.
Noise – Grading/Construction
• All equipment construction equipment shall be properly fitted with mufflers.
• All equipment staging and maintenance shall be conducted as far away from existing residences as
possible.
• All construction equipment staging and maintenance should be conducted as far away for the existing
residence as possible.
• Haul truck speed limit of 15 miles per hour shall be posted along the on-site haul route and include
signage limiting the use of engine “jake” brakes.
Noise – Blasting
• The general contractor or property owner/developer shall give reasonable notice in writing at the time
of issuance of a building permit, grading permit or encroachment license to all residences or businesses
within 600 feet of any potential blast location. The notice shall be in a form approved by the Building
Director. Any resident or business receiving such notice may request of the Building Director that a
notice of impending blasting be given by the blaster at the time of the 12 hour advance notice given to
the Building Director. The general contractor or property owner/developer shall make all reasonable
efforts to contact any and all parties requesting the second notice.
• The blaster shall file a written certification with the Building Director certifying that the general notice
required by Section 17.60.060(b) has been given. The certificate shall include addresses and date(s) of
notification. A copy shall be retained on file at the Building Division.
• Inspections of all structures within 300 feet of the blast site shall be made before blasting operations.
The persons inspecting shall obtain the permission of the building owner to conduct an inspection. The
inspections shall be done by a registered structural engineer employed by the blaster or project
contractor. The inspection shall be only for the purpose of determining the existence of any visible or
reasonably recognizable pre-existing defects or damages in any structure. Inspection refusal shall be at
the discretion of the property owner.
• Blasting shall only be permitted between the hours of 9:00 a.m. and 4:00 p.m. during any weekday,
Monday through Friday, exclusive of City recognized holidays unless special circumstances warrant
another time or day and special approval is granted by the Building Director and Fire Chief.
Heart of the City Specific Plan Amendment (Rancho Coronado) 11 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Public Services – Fire
• Roadways serving the project shall have a minimum improved paved width of 24 feet with an additional
8 feet to each side for parking. Any deviations from this or any other roadway features such as cul-de-
sacs and gates must meet the design criteria of the San Marcos Fire Department.
• Any automatic gates are required to have a Knox rapid entry system and emergency vehicle strobe
detector.
• Fire hydrants with an adequate water supply must be installed at locations approved by the San Marcos
Fire Department. Hydrant spacing shall be 300 feet apart.
• Residential structures shall be fire sprinklered per California Building Code 2010 edition and city
ordinance.
• Homes and mixed use buildings will be required to be designed using state fire marshal standards for
fire resistive construction features using the California Building Code 2013 edition Chapter 7, design to
be reviewed by City Building Department.
• A 150-foot wildland fuel modification is required from all sides of all structures.
Utilities and Service Systems
• Upsize an existing 2,700 feet of existing 8-inch wastewater collection pipe in Craven Road. This segment
is located between Santa Barbara Drive and a point approximately 575 feet south of Discovery Street.
The improvement includes 700 feet of 10-inch pipeline and 2,000 feet of 12-inch pipeline.
• Installation of a new 14-inch diameter water main loop from the intersection of Twin Oaks Valley Road
and South Village Drive to the existing 14-inch water main, approximately 1,100 feet north of South Lake
Pump Station.
• Payment of Water Capital Facility Fees per Vallecitos Water District Ordinance No. 175.
• Payment of Wastewater Capital Facility Fees per Vallecitos Water District Ordinance No. 176.
• Payment of Wastewater Density Impact Fees per Vallecitos Water District Ordinance No. 177.
Water Quality
During construction, measures would be implemented as part of the project to control erosion, sedimentation,
and pollution that could impact water resources on and off site. Prior to the commencement of grading, a Notice
of Intent must be filed with the Regional Water Quality Board for a National Pollutant Discharge Elimination
System (NPDES) General Construction Storm Water Permit. Specific permit requirements include
implementation of an approved Storm Water Pollution Prevention Plan, which requires best management
practices for erosion and sediment control related to construction activities. Standard measures that may apply
to the proposed project include:
• Surface drainage will be designed to collect and move runoff into adequately sized drainage structures
before being discharged into natural stream channels.
• Erosion control measures associated with the project will include techniques for both long- and short-
term erosion hazards. These include such measures as the short-term use of gravel bags, matting,
mulches, berms, hay bales, or similar devices along all pertinent graded areas to minimize sediment
transport.
• Native vegetation will be preserved whenever feasible, and all disturbed areas will be stabilized as soon
as possible after completion of grading.
• Use of energy dissipating structures (e.g., detention ponds, riprap, or drop structures) will be used at
storm drain outlets, drainage crossings, and/or downstream of all culverts, pipe outlets, and brow
ditches to reduce velocity and prevent erosion.
• A maintenance plan for temporary erosion control facilities will be established. This typically involves
inspection, cleaning, and repair operations being conducted after runoff-producing rainfall.
• Removal and disposal of ground water (if any) encountered during construction activities will be
coordinated with the RWQCB to ensure proper disposal methods and locations under a General
Dewatering Permit if required. This may involve specific measures such as removing excess sediment
(through the use of desilting basins, etc.) and limiting discharge velocity.
Heart of the City Specific Plan Amendment (Rancho Coronado) 12 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
• Specified fueling and maintenance procedures will be designated to preclude the discharge of
hazardous materials used during construction (e.g., fuels, lubricants, and solvents). Such designations
will include specific measures to preclude spill including proper handling and disposal techniques.
Per the project’s Water Quality Improvement Plan, the following Source Control BMPs are proposed:
• Mark all inlets with the words “No Dumping! Flows to Bay” or similar language.
• Landscaping is designed to minimize irrigation and runoff and to minimize the use of fertilizers and
pesticides that can contribute to stormwater pollution
• Landscaping in the bio-retention areas shall use California drought tolerant native grasses
• Plaza, sidewalks and parking lots shall be swept regularly to prevent the accumulation of litter and
debris.
The project is required to comply with the latest NPDES permit (Order No. R9-2013-0001) and latest City of San
Marcos Storm Water Standards Manual guidelines. The WQIP shall be approved by the City prior to issuance of
any grading permit and shall address Low Impact Development standards and hydromodification.
C. DISCRETIONARY ACTIONS
The proposed project requires the following discretionary action by the City of San Marcos:
• Amendment to the Specific Plan (SP 13-006) — An amendment of the Heart of the City Specific
Plan required to reflect the proposed project.
• Approval of Tentative Subdivision Map (TSM 13-004) — Approval of the Tentative Subdivision
map to create the individual residential lots.
D. PRIOR LAND USE PERMITTING
This section provides a background of past land use permitting on the project site.
The Hanson Operation in the Heart of the City (HOC) Specific Plan (GPA 87-09; SP 87-29) was adopted by
the City Council on January 12, 1988 and encompasses approximately 1,570 acres for the development
of California State University San Marcos (CSUSM), residential and commercial uses.
The City also approved a modification to CUP 113-86 (87 Mod), which expressly authorized mining on
835 acres within the HOC Specific Plan and required that the permittee submit a reclamation plan,
tentative subdivision map, and grading plan prior to each quarry phase. Following approval of the
modified CUP, the City entered into a Development Agreement with Hanson’s predecessors for an
approximately 960 acre area within the HOC Specific Plan identified as “Rancho Coronado” Specific Plan.
The Rancho Coronado Specific Plan encompassed the 835 acre area covered by CUP 113-86 (87 Mod)
and stated that the excavation of rock was a condition precedent to development of the Rancho
Coronado Specific Plan.
In 1992, consistent with the requirements of the prior approvals, Hanson’s predecessors submitted a
reclamation plan covering approximately 544 acres of the originally approved mining site and describing
the overall mining activities anticipated to occur in the Rancho Coronado Specific Plan. Hanson has
Heart of the City Specific Plan Amendment (Rancho Coronado) 13 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
conducted its operations consistent with the submitted reclamation plan, however, actual mining and
reclamation has been limited to 109 acres of the approved 544-acre Reclamation area.
On June 8, 1993, the City adopted a resolution, which expressly acknowledged that mining operations
on the Project Site were in compliance with CUP 113-86 (87 Mod) including the approval of a
Reclamation Plan for the Project Site.
On August 20, 2001, the City approved a Tentative Subdivision Map and Grading Plan covering
approximately 186 acres of the Heart of the City Specific Plan. These tentative maps, which were
identified as phases “M2” and M3”, were in accordance with CUP 111-85 (87 Mod) and the 1992
Reclamation Plan acknowledged by the City in Resolution 93-4244.
On December 23, 2003 as part of the obligations under TSM 418 covering Villages l, M1, M2 and M3,
Hanson obtained approval of a Habitat Loss Permit (HLP 03-08), which permits impacts to 40.5 acres of
coastal sage scrub pursuant to the California Endangered Species Act.
On December 2, 2011, the Reclamation Plan submitted by Hanson was approved for construction and a
grading permit was issued on December 7, 2011. The grading work took place between February and
April 2012 and resulted in the establishment of stabilized 2:1 slopes or less.
E. PREVIOUS CEQA REVIEW AND ENVIRONMENTAL PERMITTING
In 1987 a Mitigated Negative Declaration (ND 276-086) was prepared in conjunction with the original
Conditional Use Permit (CUP 113-86) covering the project site. Then, in 1988 a comprehensive Final EIR
(EIR 09-87) was certified by the City Council addressing the “Heart of the City” Specific Plan and an
associated amendment to the site’s original Conditional Use Permit CUP 113-86 (87 Mod). Most
recently, in 2001, Negative Declaration (ND 01-566) was certified by the City in conjunction with its
approval of TSM 418.
A Negative Declaration for the South Lake Park Master Plan (ND 08-781), south of the project site, was
certified by the City Council on April 14, 2009, and addressed impacts associated with the South Lake
Park Master Plan including a spillway realignment.
A General Industrial Permit (GIP) was issued by the State Water Resources Control Board on April 22,
1992 for the Hanson Operation closed in 2008. However, the coverage under the GIP is still valid during
the implementation of the Reclamation Closure Plan. Prior to construction of any new project activities,
a separate General Construction Permit (GCP) will be required to ensure State Water Resources Control
Board compliance for any potential project stormwater discharge.
These environmental documents are referenced as a basis for analysis and are public documents
available for reference at the City Development Services Department.
An EIR was certified as part of the General Plan Update that changed the land uses of the subject site.
Heart of the City Specific Plan Amendment (Rancho Coronado) 14 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
III. ENVIRONMENTAL CHECKLIST
A. BACKGROUND
1. Project Title: Heart of the City Specific Plan Amendment (Rancho Coronado)
2. Lead Agency Name and Address: City of San Marcos, 1 Civic Center Drive, San Marcos, CA
92069
3. Contact Person and Phone Number: Garth Koller, Project Planner, (760) 744-1050 ext. 3231,
4. Project Location: The project site sits within the boundaries of the former Hanson mining site.
The eastern and northern portions of the former Hanson mining site are disturbed from past
aggregate mining activities and the remainder of the site contains undeveloped native habitat.
The project is proposed in areas that are disturbed from previous mining.
5. Project Sponsor’s Name and Address:
Lehigh Hanson West Region
PO Box 639069
San Diego, CA 92613-9069
6. General Plan and Zoning Designations: The project site is currently zoned Specific Plan, as it falls
under the western portion of the Heart of the City Specific Plan. Under the current Specific Plan,
development within the project area could include low/medium density residential, a variety of
commercial/office professional/business park uses, open space and a park. The project will still
retain a Specific Plan designation after approval of the project.
7. Description of Project: Please see Section II for project description.
8. Surrounding land uses and setting: The project site property is bounded by Twin Oaks Valley
Road on the east, the Discovery Hills residential community on the north, and undeveloped land
on the west and south in the Barham/Discovery Hills neighborhood.
9. Other public agencies whose approval is required:
• California Department of Fish and Game (Section 1602 Permit)
• Regional Water Quality Control Board (Section 401 Certification)
• U.S .Army Corp of Engineers (Section 404 Permit)
• SWRCB (General Construction Permit, General Industrial Permit)
Heart of the City Specific Plan Amendment (Rancho Coronado) 15 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
B. ENVIRONMENTAL FACTORS POTENTIALLY AFFECTED
The environmental factors checked below would be potentially affected by this project, involving at
least one impact that is a “Mitigated to Below a Level of Significance,” as indicated by the checklist
on the following pages. All impacts identified for the project will be mitigated to below a level of
significance.
Aesthetics Agricultural and Forest Resources Air Quality
Biological Resources Cultural Resources Geology/Soils
Greenhouse Gas Hazards/Hazardous Materials Hydrology/Water Quality
Land Use/Planning Mineral Resources Noise
Population/Housing Public Services Recreation
Transportation/Traffic
Systems Utilities/ Services Systems
Mandatory Findings of Significance
C. DETERMINATION
On the basis of this initial evaluation:
I find that the proposed project COULD NOT have a significant effect on the environment, and a
NEGATIVE DECLARATION will be prepared.
I find that although the proposed project could have a significant effect on the environment,
there will not be a significant effect in this case because revisions in the project have been made
by or agreed to by the project proponent. A MITIGATED NEGATIVE DECLARATION will be
prepared.
I find that the proposed project MAY have a significant effect on the environment, and an
ENVIRONMENTAL IMPACT REPORT is required.
I find that the proposed project MAY have a “potentially significant impact” or “potentially
significant unless mitigated” impact on the environment, but at least one effect: 1) has been
adequately analyzed in an earlier document pursuant to applicable legal standards, and 2) has
been addressed by mitigation measures based on the earlier analysis as described on attached
sheets. An ENVIRONMENTAL IMPACT REPORT is required, but it must analyze only the effects
that remain to be addressed.
I find that although the proposed project could have a significant effect on the environment,
because all potentially significant effects (a) have been analyzed adequately in an earlier EIR or
NEGATIVE DECLARATION pursuant to applicable standards, and (b) have been avoided or
mitigated pursuant to that earlier EIR or NEGATIVE DECLARATION, including revisions or
mitigation measures that are imposed upon the proposed project, nothing further is required.
Date: March 19, 2014
Heart of the City Specific Plan Amendment (Rancho Coronado) 16 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Issues
Potentially
Significant
Impact
Less Than
Significant
With
Mitigation
Incorporated
Less Than
Significant
Impact
No
Impact
I. AESTHETICS. Would the proposal:
a) Have a substantial adverse effect on a scenic vista? X
b) Substantially damage scenic resources, including, but
not limited to, trees, rock outcroppings, and historic
buildings within a state scenic highway?
X
c) Substantially degrade the existing visual character or
quality of the site and its surroundings? X
d) Create a new source of substantial light or glare,
which would adversely affect day or nighttime views
in the area?
X
II. AGRICULTURAL AND FOREST RESOURCES. In determining whether impacts to agricultural resources are
significant environmental effects, lead agencies may refer to the California Agricultural Land Evaluation and
Site Assessment Model (1997) prepared by the California Department of Conservation as an optional
model to use in assessing impacts on agriculture and farmland. In determining whether impacts to forest
resources, including timberland, are significant environmental effects, lead agencies may refer to
information compiled by the California Department of Forestry and Fire Protection regarding the state’s
inventory of forest land, including the Forest Legacy Assessment Project and the carbon measurement
methodology provided in Forest Protocols adopted by the California Air resources Board. Would the
project:
a) Convert Prime Farmland, Unique Farmland, or
Farmland of Statewide Importance (Farmland), as
shown on the maps prepared pursuant to the
Farmland Mapping and Monitoring Program of the
California Resources Agency, to non-agricultural use?
X
b) Conflict with existing zoning for agricultural use, or a
Williamson Act contract? X
c) Conflict with existing zoning for, or cause rezoning of,
forest land (as defined in Public Resources Code
section 12220(g)), timberland (as defined in Public
Resources Code section 4526), or timberland zoned
Timberland Production (as defined by Government
Code section 51104(g))?
X
d) Result in the loss of forest land or conversion of
forest land to non-forest use? X
e) Involve other changes in the existing environment
which, due to their location or nature, could result in
conversion of Farmland, to non-agricultural use or
conversion of forest land to non-forest use?
X
III. AIR QUALITY. Where available, the significance criteria established by the applicable air quality
management or air pollution control district may be relied upon to make the following determinations.
Would the project:
a) Conflict with or obstruct implementation of the
applicable air quality plan? X
b) Violate any air quality standard or contribute
substantially to an existing or projected air quality
violation?
X
Heart of the City Specific Plan Amendment (Rancho Coronado) 17 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Issues
Potentially
Significant
Impact
Less Than
Significant
With
Mitigation
Incorporated
Less Than
Significant
Impact
No
Impact
c) Result in a cumulatively considerable net increase of
any criteria pollutant for which the project region is
non-attainment under an applicable federal or state
ambient air quality standard (including releasing
emissions, which exceed quantitative thresholds for
ozone precursors)?
X
d) Expose sensitive receptors to substantial pollutant
concentrations? X
e) Create objectionable odors affecting a substantial
number of people? X
IV. BIOLOGICAL RESOURCES. Would the project:
a) Have a substantial adverse effect, either directly or
through habitat modifications, on any species
identified as a candidate, sensitive, or special status
species in local or regional plans, policies, or
regulations, or by the California Department of Fish
and Game or U.S. Fish and Wildlife Service?
X
b) Have a substantial adverse effect on any riparian
habitat or other sensitive natural community
identified in local or regional plans, policies,
regulations, or by the California Department of Fish
and Game or U.S. Fish and Wildlife Service?
X
c) Have a substantial adverse effect on federally
protected wetlands as defined by Section 404 of the
Clean Water Act (including, but not limited to, marsh,
vernal pool, coastal, etc.) through direct removal,
filling, hydrological interruption, or other means?
X
d) Interfere substantially with the movement of any
native resident or migratory fish or wildlife species or
with established native resident or migratory wildlife
corridors, or impede the use of native wildlife nursery
sites?
X
e) Conflict with any local policies or ordinances
protecting biological resources, such as a tree
preservation policy or ordinance?
X
f) Conflict with the provisions of an adopted Habitat
Conservation Plan, Natural Community Conservation
Plan, or other approved local, regional or state
habitat conservation plan?
X
V. CULTURAL RESOURCES. Would the project:
a) Cause a substantial adverse change in the significance
of a historical resource as defined in §15064.5? X
b) Cause a substantial adverse change in the significance
of an archaeological resource pursuant to § 15064.5? X
c) Directly or indirectly destroy a unique paleontological
resource or site or unique geologic feature? X
Heart of the City Specific Plan Amendment (Rancho Coronado) 18 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Issues
Potentially
Significant
Impact
Less Than
Significant
With
Mitigation
Incorporated
Less Than
Significant
Impact
No
Impact
d) Disturb any human remains, including those interred
outside of formal cemeteries? X
VI. GEOLOGY AND SOILS. Would the project:
a) Expose people or structures to potential substantial
adverse effects, including the risk of loss, injury, or
death involving:
X
i) Rupture of a known earthquake fault, as delineated
on the most recent Alquist-Priolo Earthquake Fault
Zoning map, issued by the State Geologist for the
area or based on other substantial evidence of a
known fault? Refer to Division of Mines and Geology
Special Publication 42.
X
ii) Strong seismic ground shaking? X
iii) Seismic-related ground failure, including liquefaction? X
iv) Landslides? X
b) Result in substantial soil erosion or the loss of
topsoil?
X
c) Be located on a geologic unit or soil that is unstable,
or that would become unstable as a result of the
project, and potentially result in on- or off-site
landslide, lateral spreading, subsidence, liquefaction
or collapse?
X
d) Be located on expansive soil, as defined in Table 18-1-
B of the Uniform Building Code (1994), creating
substantial risks to life or property?
X
e) Have soils incapable of adequately supporting the use
of septic tanks or alternative wastewater disposal
systems where sewers are not available for the
disposal of wastewater?
X
VII. GREENHOUSE GAS EMISSIONS. Would the project:
a) Generate greenhouse gas emissions, either directly or
indirectly, that may have a significant impact on the
environment?
X
b) Conflict with any applicable plan, policy or regulation
of an agency adopted for the purpose of reducing the
emissions of greenhouse gases?
X
VIII. HAZARDS AND HAZARDOUS MATERIALS. Would the project:
a) Create a significant hazard to the public or the
environment through the routine transport, use or
disposal of hazardous materials?
X
b) Create a significant hazard to the public or the
environment through reasonable foreseeable upset
and accident conditions involving the release of
hazardous materials into the environment?
X
Heart of the City Specific Plan Amendment (Rancho Coronado) 19 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Issues
Potentially
Significant
Impact
Less Than
Significant
With
Mitigation
Incorporated
Less Than
Significant
Impact
No
Impact
c) Emit hazardous emissions or handle hazardous or
acutely hazardous materials, substances, or waste
within one-quarter mile of an existing or proposed
school?
X
d) Be located on a site which is included on a list of
hazardous materials sites compiled pursuant to
Government code Section 65962.5 and, as a result,
would it create a significant hazard to the public or
the environment?
X
e) For a project located within an airport land use plan
or, where such a plan has not been adopted, within
two miles or a public airport or public use airport,
would the project result in a safety hazard for people
residing or working in the project area?
X
f) For a project within the vicinity of a private airstrip,
would the project result in a safety hazard for people
residing or working in the project area?
X
g) Impair implementation of or physically interfere with
an adopted emergency response plan or emergency
evacuation plan?
X
h) Expose people or structures to a significant risk of
loss, injury or death involving wildland fires, including
where wildlands are adjacent to urbanized areas or
where residences are intermixed with wildlands?
X
IX. HYDROLOGY AND WATER QUALITY. Would the project:
a) Violate any water quality standards or waste
discharge requirements? X
b) Substantially deplete groundwater supplies or
interfere substantially with groundwater recharge,
such that there would be a net deficit in aquifer
volume or a lowering of the local groundwater table
level (e.g., the production rate of pre-existing nearby
wells would drop to a level which would not support
existing land uses or planned uses for which permits
have been granted)?
X
c) Substantially alter the existing drainage pattern of
the site or area, including through the alteration of
the course of a stream or river, in a manner which
would result in substantial erosion or siltation on- or
off-site?
X
d) Substantially alter the existing drainage pattern of
the site or area, including through the alteration of
the course of a stream or river, or substantially
increase the rate or amount of surface runoff in a
manner, which would result in flooding on- or off-
site?
X
Heart of the City Specific Plan Amendment (Rancho Coronado) 20 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Issues
Potentially
Significant
Impact
Less Than
Significant
With
Mitigation
Incorporated
Less Than
Significant
Impact
No
Impact
e) Create a significant adverse environmental impact to
drainage patterns due to changes in runoff flow rates
or volumes?
X
f) Substantially alter the existing drainage pattern of
the site or area, including through the alteration of
the course of a stream or river, or substantially
increase the rate or amount of surface runoff in a
manner, which would result in flooding on-or off-
site?
X
g) Create or contribute runoff water which would
exceed the capacity of existing or planned storm
water drainage systems or provide substantial
additional sources of polluted runoff?
X
h) Result in increased impervious surfaces and
associated increased runoff? X
i) Result in significant alteration of receiving water
quality during or following construction? X
j) Result in an increase in pollutant discharges to
receiving waters? Consider water quality parameters
such as temperature, dissolved oxygen, turbidity and
other typical storm water pollutants (e.g. heavy
metals, pathogens, petroleum derivatives, synthetic
organics, sediment, nutrients, oxygen-demanding
substances, and trash).
X
k) Be tributary to an already impaired water body as
listed on the Clean Water Act Section 303(d) list. If so,
can it result in an increase in any pollutant for which
the water body is already impaired?
X
l) Be tributary to environmentally sensitive areas (e.g.
MSCP, RARE, Areas of Special Biological Significance,
etc.)? If so, can it exacerbate already existing
sensitive conditions?
X
m) Have a potentially significant environmental impact
on surface water quality, to either marine, fresh or
wetland waters?
X
n) Otherwise substantially degrade water quality? X
o) Place housing within a 100-year flood hazard area as
mapped on a federal Flood Hazard Boundary or Flood
Insurance Rate Map or other flood hazard delineation
map?
X
p) Place within a 100-year flood hazard area structures
which would impede or redirect flood flows? X
q) Expose people or structures to a significant risk of
loss, injury or death involving flooding, including
flooding as a result of the failure of a levee or dam?
X
r) Inundation by seiche, tsunami, or mudflow? X
Heart of the City Specific Plan Amendment (Rancho Coronado) 21 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Issues
Potentially
Significant
Impact
Less Than
Significant
With
Mitigation
Incorporated
Less Than
Significant
Impact
No
Impact
X. LAND USE AND PLANNING. Would the project:
a) Physically divide an established community? X
b) Conflict with any applicable land use plan, policy, or
regulation of an agency with jurisdiction over the
project (including, but not limited to the general plan,
specific plan, local coastal program, or zoning
ordinance) adopted for the purpose of avoiding or
mitigating an environmental effect?
X
c) Conflict with any applicable habitat conservation plan
or natural community conservation plan? X
XI. MINERAL RESOURCES. Would the project:
a) Result in the loss of availability of a known mineral
resource that would be a value to the region and the
residents of the state?
X
b) Result in the loss of availability of a locally important
mineral resource recovery site delineated on a local
general plan, specific plan or other land use plan?
X
XII. NOISE. Would the project result in:
a) Exposure of persons to or generation of noise levels
in excess of standards established in the local general
plan or noise ordinance, or applicable standards of
other agencies?
X
b) Exposure of persons to or generation of excessive
groundborne vibration or groundborne noise levels? X
c) A substantial permanent increase in ambient noise
levels in the project vicinity above levels existing
without the project?
X
d) A substantial temporary or periodic increase in
ambient noise levels in the project vicinity above
levels existing without the project?
X
e) For a project located within an airport land use plan
or, where such a plan has not been adopted, within
two miles of a public airport or public use airport,
would the project expose people residing or working
in the project area to excessive noise levels?
X
f) For a project within the vicinity of a private airstrip,
would the project expose people residing or working
in the project area to excessive noise levels?
X
XIII. POPULATION AND HOUSING. Would the project:
a) Induce substantial population growth in an area,
either directly (for example, by proposing new homes
and businesses) or indirectly (for example, through
extension of roads or other infrastructure)?
X
b) Displace substantial numbers of existing housing,
necessitating the construction of replacement
housing elsewhere?
X
Heart of the City Specific Plan Amendment (Rancho Coronado) 22 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Issues
Potentially
Significant
Impact
Less Than
Significant
With
Mitigation
Incorporated
Less Than
Significant
Impact
No
Impact
c) Displace substantial numbers of people, necessitating
the construction of replacement housing elsewhere? X
XIV. PUBLIC SERVICES. Would the project result in substantial adverse physical impacts associated with the
provision of new or physically altered governmental facilities, need for new or physically altered
governmental facilities, the construction of which could cause significant environmental impacts, in order
to maintain acceptable service ratios, response times or other performance objectives for any of the public
services:
a) Fire protection? X
b) Police protection? X
c) Schools? X
d) Parks? X
e) Other public facilities? X
XV. RECREATION.
a) Would the project increase the use of existing
neighborhood and regional parks or other
recreational facilities, such that substantial physical
deterioration of the facility would occur or be
accelerated?
X
b) Does the project include recreational facilities or
require the construction or expansion of recreational
facilities, which might have an adverse physical effect
on the environment?
X
XVI. TRANSPORTATION/TRAFFIC. Would the project:
a) Cause an increase in traffic, which is substantial in
relation to the existing traffic load and capacity of the
street system (i.e., result in a substantial increase in
either the number of vehicle trips, the volume to
capacity ratio on roads, or congestion at
intersections)?
X
b) Exceed, either individually or cumulatively, a level of
service standard established by the county
congestion management agency for designated roads
or highways?
X
c) Result in a change in air traffic patterns, including
either an increase in traffic levels or a change in
location that results in substantial safety risks?
X
d) Substantially increase hazards due to a design feature
(e.g., sharp curves or dangerous intersections) or
incompatible uses (e.g., farm equipment)?
X
e) Result in inadequate emergency access? X
f) Result in inadequate parking capacity? X
g) Conflict with adopted policies, plans, or programs
supporting alternative transportation (e.g., bus
turnouts, bicycle racks)?
X
Heart of the City Specific Plan Amendment (Rancho Coronado) 23 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Issues
Potentially
Significant
Impact
Less Than
Significant
With
Mitigation
Incorporated
Less Than
Significant
Impact
No
Impact
XVII. UTILITIES AND SERVICE SYSTEMS. Would the project:
a) Exceed wastewater treatment requirements of the
applicable Regional Water Quality Control Board? X
b) Require or result in the construction of new water or
wastewater treatment facilities or expansion of
existing facilities, the construction of which could
cause significant environmental effects?
X
c) Require or result in the construction of new storm
water drainage facilities or expansion of existing
facilities, the construction of which could cause
significant environmental effects?
X
d) Have sufficient water supplies available to serve the
project from existing entitlements and resources or
are new or expanded entitlements needed?
X
e) Result in a determination by the wastewater
treatment provider, which serves or may serve the
project that it has adequate capacity to serve the
project’s projected demand in addition to the
provider’s existing commitments?
X
f) Be served by a landfill with sufficient permitted
capacity to accommodate the project’s solid waste
disposal needs?
X
g) Comply with federal, state, and local statutes and
regulations related to solid waste? X
XVIII. MANDATORY FINDINGS OF SIGNIFICANCE.
a) Does the project have the potential to degrade the
quality of the environment, substantially reduce the
habitat of a fish or wildlife species, cause a fish or
wildlife population to drop below self-sustaining
levels, threaten to eliminate a plant or animal
community, reduce the number or restrict the range
of a rare or endangered plant or animal or eliminate
important examples of the major periods of California
history or prehistory?
X
b) Does the project have impacts that are individually
limited, but cumulatively considerable?
("Cumulatively considerable" means that the
incremental effects of a project are considerable
when viewed in connection with the effects of past
projects, the effects of other current projects, and
the effects of probable future projects.)
X
c) Does the project have environmental effects, which
will cause substantial adverse effects on human
beings, either directly or indirectly?
X
Heart of the City Specific Plan Amendment (Rancho Coronado) 24 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
IV. ENVIRONMENTAL ANALYSIS
This section provides an evaluation of the impact categories and questions contained in the
Environmental Checklist.
I. AESTHETICS
a) Have a substantial adverse effect on a scenic vista? Less than Significant Impact.
The project site is located between Mount Whitney and Double Peak Mountain in a valley of land
with disturbed habitat and soil disturbed by the closed Hanson Operation as well as natural open
space areas. The project site is located within the Barham/Discovery community plan area in the City
of San Marcos. Portions of these community plan areas contain scenic corridors are listed in the San
Marcos General Plan.
Topographically, the site consists of cut slope and fill areas resulting from previous site grading
activities as well as natural open space areas. The project site is located within an overall hillside and
valley terrain. Existing elevations range from a high of approximately 875 feet above mean sea level
(msl) in the southeastern portion of the site to a low of approximately 720 feet msl in the northern
portion of the project site.
Proposed development would occur within in areas that have already been disturbed from past
mining activities. Proposed residential development in Areas A, B, C and D and the future non-
residential mixed-use development (business park) would appear as an extension of existing
development north and east of the project site.
The project will preserve approximately 129 acres of open space areas which provides a visual
amenity from both onsite and offsite. These habitat preservation areas include large areas of coastal
sage scrub which will connect to existing preserve areas to the south of the project site. The
preservation of over half of the project site as open space areas will contribute to scenic vistas in the
area. Project impacts would be less than significant.
b) Substantially damage scenic resources, including, but not limited to, trees, rock outcroppings,
and historic buildings within a State Scenic Highway? No Impact
The project site is located approximately 1.2 miles south of State Route 78 (SR-78). A portion of
SR-78 is recognized as a Scenic Highway by Caltrans; however, that portion is not in the project
vicinity. The portion identified as a Scenic Highway is approximately 50 miles east of the project site
near Anza Borrego (Caltrans 2013). Thus the project would not impact a State scenic highway.
At a local level, SR-78 is designated by the City as a view corridor. The highway corridor provides
view of the Merriam Mountains, Mount Whitney, Double Peak, CSUSM and Palomar Community
College. The proposed development would not impact views to these peaks from SR-78 since it is
situated at a lower elevation.
The City has a Ridgeline Protection and Management Overlay Zone (RPMOZ) which is designed to
protect natural viewsheds and unique natural resources, and to minimize physical impacts to select
primary and secondary ridgelines. These protected primary and secondary ridgelines are shown on
Heart of the City Specific Plan Amendment (Rancho Coronado) 25 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Figure 4-5 of the Conservation and Open Space Element of the City’s General Plan. Development is
not proposed on areas identified as primary or secondary ridgeline.
The project site is vacant and does not support any historic buildings. Cultural resources reports for
the project have not identified any historic buildings on the project site. Therefore the project would
not damage any historic buildings.
In addition, the project site does not support any significant trees, rock outcroppings or historic
buildings as identified or protected by the City’s General Plan. Therefore no impact is identified.
c) Substantially degrade the existing visual character or quality of the site and its surroundings?
Less than Significant Impact
The existing visual character of the area is that of single-family homes to the north, multi-family
homes to the east, and South Lake to the south, location of a future park. The site has varying
topography, with steep slopes in several areas. Natural vegetation on the project site includes a
combination of upland and wetland habitats.
Portion of the project site currently supports stabilized slopes created as a function of the Hanson
Operation closure plan and natural habitat that has grown on areas previously disturbed by the
mining operations. Northwest views to the City and the SR-78 corridor are an existing visual amenity
from the project site.
Visual changes to the site would include grading activities to provide access to the project site, as
well as development of a single-family residential, non-residential mixed use (business park), and an
active recreation park. The originally approved tentative map for the subject site would have
allowed for the construction of residential units in the area where the non-residential mixed use and
public amenities are now proposed. The visual character of this area of Heart of the City is
residential with single-family homes to the north and multi-family residential homes to the east. The
development of residential, non-residential mixed use (business park/retail), and an active park is
consistent with the residential character of this area which is defined by other slopes in the area
with heights up to 80 feet as permitted through the Heart of the City Specific Plan.
Future residential development on the project site (Areas A, B, C and D) will be guided by the
Rancho Coronado Residential Design Guidelines (Appendix A.3 of this document) which detail the
requirements for architecture and landscaping for the future residential areas. A multi-theme
Mediterranean style is proposed for the future residences with a requirement for articulation of
massing to make the homes appear smaller, convey a sense of human scale, and to avoid a
monotonous appearance. A comprehensive landscape plan will further add to the visual interest of
the project and also provide screening from offsite areas.
Future development within the non-residential mixed use development area will be guided by the
requirements of the Heart of the City Specific Plan which requires the smooth masonry, brick, tile,
and tinted or lightly reflective glass. Highly reflective dark glass is not permitted.
Finally, the project will preserve approximately 129 acres of open space areas which provides a
visual amenity from both onsite and offsite. These habitat preservation areas include large areas of
coastal sage scrub which will connect to existing preserve areas to the south of the project site.
Heart of the City Specific Plan Amendment (Rancho Coronado) 26 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
As such, the proposed project would not significantly change the visual character or quality of the
site and surroundings, and therefore impacts are determined to be less than significant.
d) Create a new source of substantial light or glare, which would adversely affect day or
nighttime views in the area? Less than Significant Impact
Development of the proposed project would add lighting to an area that is currently undeveloped
and does not have lighting.
Lighting proposed under the project would be guided by standards set by the City of San Marcos,
which requires downward-directed LED lighting, with the exception of specialized streetscape
lighting or architectural detail lighting. These requirements aid in the preservation of dark-sky
conditions, which are needed by the local observatories. Development under the project would also
be required to comply with the City’s lighting standards, and the location, type, and direction of the
lighting would be reviewed during Improvement Plan review to ensure compliance with City
requirements. Thus impacts related to substantial light pollution are determined to be less than
significant.
The active park will have sports fields that may include lighting. At this time there is not a specific
development plan for the park area. It is anticipated that the use of lighting for night games would
be limited and would be subject to timing limits so as to not disturb adjacent residential uses. At the
time a park plan is developed, the park plan would be subject to additional environmental review,
which would include a review of the proposed lighting to determine any impacts related to night
lighting. Therefore, impacts are less than significant.
The project does not propose features that would be characterized as creating a new source of glare
that would adversely affect daytime or nighttime views. Chapter 3 of the Rancho Coronado
Residential Design Guidelines (Appendix A.3 of this document) details the materials and colors to be
used in the future residential development areas. The homes would incorporate earth-toned roof
tiles and stucco surface that will be in soft earth tones. These roof and wall colors and materials are
not significant sources of glare. Section 3.3.3 of the Heart of the City Specific Plan (Appendix A.2 of
this document) details the required materials for future business park development. Required
materials include smooth masonry, brick, tile, and tinted or lightly reflective glass. Highly reflective
dark glass is not permitted.
Since project will use lighting in an unobtrusive manner and will be required to comply with the
lighting standards set for by the City and the proposed materials to be used in the homes and future
mixed-use non-residential area are not glare-inducing, impacts related to lighting and glare would
be less than significant.
II. AGRICULTURE RESOURCES
a) Convert Prime Farmland, Unique Farmland, or Farmland of Statewide Importance (Farmland),
as shown on the maps prepared pursuant to the Farmland Mapping and Monitoring Program
of the California Resources Agency, to non-agricultural use? No Impact
The project site does not fall under areas mapped as prime farmland, unique farmland or farmland
of statewide importance, as determined by the Farmland Mapping and Monitoring Program, as
Heart of the City Specific Plan Amendment (Rancho Coronado) 27 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
shown in San Marcos General Plan (Figure 4-4, Agricultural Areas). Therefore, the project would not
result in the conversion of such lands and no impact is identified for this issue area.
b) Conflict with existing zoning for agricultural use, or a Williamson Act contract? No Impact.
The project site is not located within a Williamson Act contract area, as shown in the San Marcos
General Plan (Figure 4-4, Agricultural Areas). Further, the project site is not zoned for agricultural
use. The project site is currently zoned Specific Plan, and that zoning designation will be retained
with implementation of the proposed project. Therefore, no impact is identified for this issue area.
c) Conflict with existing zoning for, or cause rezoning of, forest land (as defined in Public
Resources Code section 12220(g)), timberland (as defined in Public Resources Code section
4526), or timberland zoned Timberland Production (as defined by Government Code section
51104(g))? No Impact
The proposed project is not located in an area that is zoned for forest land, timber land or for timber
production. The project site is zoned Specific Plan and will retain that designation with
implementation of the proposed project. Therefore, no impact is identified.
d) Result in the loss of forest land or conversion of forest land to non-forest use? No Impact
The project site does not support forests, nor is there any forest land adjacent to the project site.
The project development will be adjacent to existing residential development on the north, Twin
Oaks Valley Road to the east and future park space and preserved open space (which is not
forestland) to the west and south. Therefore, the proposed project will not result in the loss of
forest land or the conversion of forest land to non-forest use. No impact is identified for this issue
area.
e) Involve other changes in the existing environment which, due to their location or nature,
could result in conversion of Farmland, to non-agricultural use or conversion of forest land to
non-forest use?? No Impact
The project does not involve other changes in the existing environment which, due to their location
or nature could result in conversion of Farmland to non-agricultural use or conversion of forest land
to non-forest use. The project site does not support any agricultural or timber uses, nor is it adjacent
to such uses. Therefore, no impact is identified for this issue area.
III. AIR QUALITY
An air conformity analysis was prepared for the project by Scientific Resources Associates (2014a)
and is included as Appendix B.
a) Conflict with or obstruct implementation of the applicable air quality plan? Less Than
Significant Impact
Projects that are consistent with existing General Plan documents, which are used to develop air
emissions budgets for the purpose of air quality planning and attainment demonstrations, would be
consistent with the San Diego Air Basin’s (SDAB) air quality plans, including the Regional Air Quality
Heart of the City Specific Plan Amendment (Rancho Coronado) 28 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Strategy (RAQS) and the State Implementation Plan (SIP). Both of these air quality plans contain
strategies for the region to attain and maintain the ambient air quality standards. Provided a
project proposes the same or less development as accounted for in the General Plan document, and
provided the project is in compliance with applicable Rules and Regulations adopted by the San
Diego Air Pollution Control District (SDAPCD) through their air quality planning process, the project
would not conflict with or obstruct implementation of the RAQS or SIP.
The project involves construction of 346 single- and paired single-family residential units in four
residential areas, along with development of a 24.1-acre mixed-use development. While specific
development is not proposed within this area at this time, the environmental analysis assume 90
percent of the non-residential mixed use area would be developed with business park uses and the
remaining 10 percent would be retail with a total of 240,000 s.f. developed on the 24.1 acres. The
project will serve existing and future housing needs within the City of San Marcos, and is consistent
with the City’s Heart of the City Specific Plan.
The project will comply with all applicable rules and regulations that have been adopted as part of
the SIP. Because the project is consistent with the goals of the RAQS and SIP, the project would not
conflict with or obstruct implementation of the RAQS and SIP, and impacts would be less than
significant.
In summary, implementation of the project would not conflict with or obstruct implementation of
applicable air quality plans and a less than significant impact is identified.
b) Violate any air quality standard or contribute substantially to an existing or projected air
quality violation? Less Than Significant Impact
Table 3 shows the state and federal attainment status for criteria pollutants in the San Diego Air
Basin (SDAB). As shown in Table 3, the SDAB is a nonattainment area for the state and federal O3
standards, and for the state PM10 and PM2.5 standards.
Table 3. Attainment Status of Criteria Pollutants in San Diego Air Basin
Pollutant State Federal
1-hour Ozone (O3) Serious Nonattainment Revoked June 2005
8-hour O3 Nonattainment Marginal Nonattainment
Particulate Matter−10 microns (PM10) Nonattainment Unclassified
Particulate Matter−2.5 microns (PM2.5) Nonattainment Unclassified/Attainment
Carbon Monoxide (CO) Attainment Maintenance
Nitrogen Dioxide (NO2) Attainment Unclassified/Attainment
Sulfur Dioxide (SO2) Attainment Attainment
Lead Attainment Unclassified/Attainment
All others Unclassified/Attainment N/A
Source: California Air Resources Board: http://www.arb.ca.gov/desig/adm/adm.htm. April 2013.
The SCAQMD establishes significance criteria for air quality emissions. The aggregate project-related
maximum levels are shown in Table 4. Any project with daily construction- or operation-related
emissions that exceed any of the following thresholds should be considered as having an individually
and cumulatively significant air quality impact.
Heart of the City Specific Plan Amendment (Rancho Coronado) 29 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 4. Screening-Level Criteria for Air Quality Impacts
Pollutant Total Emissions
Construction Emissions Lb. per Day
Respirable Particulate Matter (PM10) 100
Fine Particulate Matter (PM2.5) 100
Oxides of Nitrogen (NOx) 250
Oxides of Sulfur (SOx) 250
Carbon Monoxide (CO) 550
Volatile Organic Compounds (VOCs)1
137
Operational Emissions Lb. Per Hour Lb. per Day Tons per Year
Respirable Particulate Matter (PM10) --- 100 15
Fine Particulate Matter (PM2.5) --- 100 15
Oxides of Nitrogen (NOx) 25 250 40
Oxides of Sulfur (SOx) 25 250 40
Carbon Monoxide (CO) 100 550 100
Lead and Lead Compounds --- 3.2 0.6
Volatile Organic Compounds (VOC)2
--- 137 15
To determine whether a project would result in emissions that would violate any air quality
standard or contribute substantially to an existing or projected air quality violation; project
emissions may be evaluated based on the quantitative emission thresholds established by the San
Diego APCD.
As part of its air quality permitting process, the APCD has established thresholds in Rule 20.2 for the
preparation of Air Quality Impact Assessments (AQIA). For CEQA purposes, these screening criteria
can be used as numeric methods to demonstrate that a project’s total emissions would not result in
a significant impact to air quality. Since APCD does not have AQIA thresholds for emissions of VOCs,
the use of the threshold for VOCs from the City of San Diego’s Significance Thresholds (City of San
Diego 2007) is appropriate. The screening thresholds are presented in Table 4.
The thresholds listed in Table 4 represent screening-level thresholds that can be used to evaluate
whether project-related emissions could cause a significant impact on air quality. Emissions below
the screening-level thresholds would not cause a significant impact. In the event that emissions
exceed these thresholds, modeling would be required to demonstrate that the project’s total air
quality impacts result in ground-level concentrations that are below the State and Federal Ambient
Air Quality Standards, including appropriate background levels. For nonattainment pollutants
(ozone, with ozone precursors NOx and VOCs, and PM10), if emissions exceed the thresholds shown
in Table 4, the project could have the potential to result in a cumulatively considerable net increase
in these pollutants and thus could have a significant impact on the ambient air quality.
Construction Emissions
Construction activities, including soil disturbance dust emissions and combustion pollutants from
on-site construction equipment and from off-site trucks hauling dirt, cement or building materials,
will create a temporary addition of pollutants to the local airshed. The proposed project will involve
grading activities. Grading for the project includes 2,608,200 cubic yards (cy) of cut and 2,853,800 of
fill and will balance onsite. The grading quantities assume a 15 to 18 percent bulking factor. No
Heart of the City Specific Plan Amendment (Rancho Coronado) 30 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
offsite export or import will be required for the project. Due to underlying bedrock conditions,
blasting will be required as part of the project construction. The following equipment will be used on
site for construction:
• Tractor/backhoe
• Dozer-D9
• Hydraulic Crane
• Loader/Grader
• Side Boom
• Water Truck
• Rock Crusher (potential)
• Concrete Truck
• Concrete Pump
• Dump/Haul Trucks
• Paver/Blade
• Roller/Compactor
• Scraper
• Drill Rig (for borings in rock prior to blasting)
Project phasing will include an overall grading phase commencing in 2014. The grading phase would
include blasting and rock crushing. Phase 1 construction will start in 2015 and is anticipated to be
completed by late 2016 or early 2017. Phase 1 includes Residential Area A and B (126 dwelling
units), Backbone Road from Santa Barbara Drive to North Village Drive, and North Village Drive
extended west to Backbone Road.
Phase 2 construction is anticipated to start in 2017 and be complete by 2020. Phase 2 includes
construction of 220 dwelling units in Residential Areas C and D; construction of the 24.1-acre mixed-
use portion of the project, which will include 90 percent business park and 10 percent retail;
construction of a 38-acre active park; construction of Backbone Road from North Village Drive to
South Village Drive; construction of South Village Drive extended west to Backbone Road;
installation of a new signal for access to the mixed use site, and construction of the access road for
the mixed use site.
Fugitive dust emissions associated with blasting were estimated based on the U.S. EPA’s emission
factor for blasting for coal mining to remove overburden, which is a similar process.
Table 5a presents the model results for the construction of the project. Construction projects within
the City of San Marcos would be required to implement fugitive dust control measures during
grading, which would include watering the site a minimum of twice daily to control dust, as well as
reducing speeds on unpaved surfaces to 15 mph or less, replacing ground cover in disturbed areas
quickly, and reducing dust during loading/unloading of dirt and other materials. Also, projects
would utilize low-VOC paints that would not exceed 100 grams of VOC per liter for interior surface
and 150 grams of VOC per liter for exterior surfaces, in accordance with the requirements of APCD
Rule 67.0 for architectural coatings. These two requirements have been identified as project design
features for the project in Table 2. Thus Table 5a presents an estimate of the maximum daily
construction emissions, assuming that these construction project design features will be employed.
Heart of the City Specific Plan Amendment (Rancho Coronado) 31 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 5a. Construction Emissions – Proposed Project
Construction Project/Phase VOC NOx CO SO2 PM10 PM2.5
Site Grading
Grading – Area C & D
Fugitive Dust – Blasting - - - - 30.79 9.23
Explosives Emissions - 8.50 33.50 - - -
Fugitive Dust - Rock Crushing - - - - 7.12 2.14
Fugitive Dust - Earthmoving - - - - 3.17 1.41
Off-Road Diesel 12.98 148.08 82.44 0.14 6.71 6.21
Hauling Truck Trips 14.82 39.10 217.83 0.04 0.32 0.19
Worker Trips 0.15 0.17 1.88 0.004 0.31 0.09
Total 27.95 195.85 335.65 0.18 48.42 19.27
Significance Threshold 137 250 550 250 100 100
Above Threshold? No No No No No No
Grading – Area B
Fugitive Dust - Earthmoving - - - - 3.46 1.44
Off-Road Diesel 11.67 136.15 75.78 0.12 6.02 5.54
Hauling Truck Trips 14.65 38.67 215.41 0.04 0.32 0.19
Worker Trips 0.13 0.15 1.63 0.003 0.27 0.07
Total 26.45 174.97 292.82 0.16 10.07 7.24
Significance Threshold 137 250 550 250 100 100
Above Threshold? No No No No No No
Grading – Area A
Fugitive Dust - Earthmoving - - - - 3.05 1.40
Off-Road Diesel 11.67 136.15 75.78 0.12 6.02 5.54
Hauling Truck Trips 14.45 38.14 212.48 0.04 0.31 0.19
Worker Trips 0.13 0.15 1.63 0.003 0.27 0.07
Total 26.25 174.44 289.89 0.16 9.65 7.20
Significance Threshold 137 250 550 250 100 100
Above Threshold? No No No No No No
Grading – Area M-3
Fugitive Dust – Blasting - - - - 30.79 9.23
Explosives Emissions - 8.50 33.50 - - -
Fugitive Dust - Rock Crushing - - - - 7.12 2.14
Fugitive Dust - Earthmoving - - - - 3.18 1.41
Off-Road Diesel 13.70 153.34 86.29 0.14 7.09 6.59
Hauling Truck Trips 14.78 39.00 217.29 0.04 0.32 0.19
Worker Trips 0.15 0.17 1.88 0.004 0.31 0.09
Total 28.63 201.01 338.96 0.18 48.81 19.65
Significance Threshold 137 250 550 250 100 100
Above Threshold No No No No No No
Heart of the City Specific Plan Amendment (Rancho Coronado) 32 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Construction Project/Phase VOC NOx CO SO2 PM10 PM2.5
Grading – Backbone Roadway
Fugitive Dust – Blasting - - - - 30.79 9.23
Explosives Emissions - 8.50 33.50 - - -
Fugitive Dust - Rock Crushing - - - - 7.12 2.14
Fugitive Dust - Earthmoving - - - - 3.28 1.42
Off-Road Diesel 12.96 147.76 82.32 0.14 6.70 6.20
Hauling Truck Trips 14.72 38.85 216.44 0.04 0.32 0.19
Worker Trips 0.15 0.17 1.88 0.004 0.31 0.09
Total 27.83 195.28 334.14 0.18 48.52 19.27
Significance Threshold 137 250 550 250 100 100
Above Threshold No No No No No No
Grading - Channel
Fugitive Dust – Blasting - - - - 30.79 9.23
Explosives Emissions - 8.50 33.50 - - -
Fugitive Dust - Rock Crushing - - - - 7.12 2.14
Fugitive Dust - Earthmoving - - - - 3.38 1.43
Off-Road Diesel 11.64 135.86 75.67 0.12 6.01 5.53
Hauling Truck Trips 14.03 37.02 206.22 0.03 0.30 0.18
Worker Trips 0.13 0.15 1.63 0.003 0.27 0.07
Total 25.80 181.53 317.02 0.15 47.87 18.58
Significance Threshold 137 250 550 250 100 100
Above Threshold No No No No No No
Maximum Simultaneous
Construction Emissions, Grading 28.63 201.01 338.96 0.18 48.81 19.65
Significance Threshold 137 250 550 250 100 100
Above Threshold? No No No No No No
Phase 1 Construction
Building Construction
Building Construction Off-Road
Diesel 3.66 30.03 18.74 0.03 2.11 1.99
Building Construction Vendor Trips 2.57 12.33 13.73 0.03 0.95 0.40
Building Construction Worker Trips 4.43 1.36 14.88 0.03 2.49 0.67
Total 10.66 43.72 47.35 0.09 5.55 3.06
Significance Threshold 137 250 550 250 100 100
Above Threshold? No No No No No No
Paving
Asphalt Offgassing 0.28 - - - - -
Paving Off-Road Diesel 5.30 52.39 28.79 0.051 2.93 2.76
Paving On-Road Diesel 0.23 1.09 1.21 0.002 0.08 0.04
Paving Worker Trips 0.37 0.11 1.24 0.003 0.21 0.06
Total 6.18 53.59 31.24 0.06 3.22 2.86
Significance Threshold 137 250 550 250 100 100
Above Threshold? No No No No No No
Heart of the City Specific Plan Amendment (Rancho Coronado) 33 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Construction Project/Phase VOC NOx CO SO2 PM10 PM2.5
Architectural Coatings Use
Architectural Coating Offgassing 24.31 - - - - -
Off-Road Diesel 0.41 2.57 1.90 0.003 0.22 0.22
Architectural Coatings Worker Trips 0.88 0.27 2.97 0.006 0.50 0.13
Total 25.60 2.84 4.87 0.01 0.72 0.35
Significance Threshold 137 250 550 250 100 100
Above Threshold? No No No No No No
Maximum Simultaneous
Construction Emissions, Phase 1 36.26 97.31 78.59 0.14 8.78 5.92
Significance Threshold 137 250 550 250 100 100
Above Threshold? No No No No No No
Phase 2 Construction
Building Construction
Building Construction Off-Road
Diesel 3.10 26.41 18.13 0.03 1.78 1.67
Building Construction Vendor Trips 2.96 13.81 17.02 0.04 1.28 0.50
Building Construction Worker Trips 5.26 1.54 16.67 0.04 3.41 0.92
Total 11.32 41.76 51.82 0.11 6.47 3.09
Significance Threshold 137 250 550 250 100 100
Above Threshold? No No No No No No
Paving
Asphalt Offgassing 0.28 - - - - -
Paving Off-Road Diesel 4.43 43.19 27.94 0.051 2.37 2.23
Paving On-Road Diesel 0.18 0.85 1.04 0.002 0.08 0.03
Paving Worker Trips 0.32 0.09 1.01 0.003 0.21 0.06
Total 5.21 44.13 29.99 0.06 2.66 2.32
Significance Threshold 137 250 550 250 100 100
Above Threshold? No No No No No No
Architectural Coatings Use
Architectural Coating Offgassing 22.14 - - - - -
Off-Road Diesel 0.33 2.19 1.87 0.002 0.17 0.17
Architectural Coatings Worker Trips 1.05 0.31 3.32 0.009 0.68 0.18
Total 23.52 2.50 5.19 0.01 0.85 0.35
Significance Threshold 137 250 550 250 100 100
Above Threshold? No No No No No No
Maximum Simultaneous
Construction Emissions, Phase 2 40.05 88.38 87.00 0.18 9.98 5.76
Significance Threshold 137 250 550 250 100 100
Above Threshold? No No No No No No
Heart of the City Specific Plan Amendment (Rancho Coronado) 34 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
As shown in Table 5a, maximum daily emissions of all criteria pollutants would be below the
significance thresholds for all criteria pollutants. The mitigation measures assumed are as follows:
Operational Emissions
Operational impacts associated with the Rancho Coronado Specific Plan would include emissions
associated with vehicular traffic, as well as area sources such as energy use, consumer products use,
and architectural coatings use for maintenance purposes. Emissions associated with project
operations were estimated using the CalEEMod Model, based on the project’s overall trip
generation of 8,926 ADT (RBF Consulting 2014). For the purpose of estimating emissions, it was
assumed that each residence would have a fireplace, and that the fireplaces would be natural gas-
fired only.
Table 5b provides a summary of the estimated operational emissions for the Rancho Coronado
Specific Plan project.
Table 5b. Operational Emissions – Proposed Project
VOC NOx CO SOx PM10 PM2.5
Summer Day, Lbs/day
Area Sources 64.24 0.33 28.71 0.001 0.62 0.62
Energy Use 0.50 4.38 2.68 0.03 0.35 0.35
Vehicular Emissions 60.41 45.61 225.74 0.63 42.66 11.85
TOTAL 125.15 50.33 257.13 0.66 43.63 12.81
Significance Screening Criteria 137 250 550 250 100 55
Above Screening Criteria? No No No No No No
Winter Day, Lbs/day
Area Sources 64.24 0.33 28.71 0.001 0.62 0.62
Energy Use 0.50 4.38 2.68 0.03 0.35 0.35
Vehicular Emissions 72.04 48.44 242.49 0.60 42.67 11.85
TOTAL 136.78 53.15 273.87 0.62 43.63 12.81
Significance Screening Criteria 137 250 550 250 100 55
Above Screening Criteria? No No No No No No
Operational emissions associated with the Rancho Coronado Specific Plan would be below the
significance criteria for operations. Air quality impacts would therefore be less than significant.
CO Hot Spot Analysis
Operational emissions associated with the Rancho Coronado Specific Plan would be below the
significance criteria for operations. Air quality impacts would therefore be less than significant.
Projects that involve traffic impacts may have the potential for CO “hot spots” to occur (i.e., high
concentrations of CO at intersections). The Traffic Impact Analysis Report (RBF Consulting 2014)
indicated that project-related traffic would result in a significant impact at the following
intersections:
Heart of the City Specific Plan Amendment (Rancho Coronado) 35 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
2016 Conditions
• Twin Oaks Valley Road and SR-78 Eastbound Ramps
2020 Conditions
• Twin Oaks Valley Road and SR-78 Eastbound Ramps
2030 Conditions
• Twin Oaks Valley Road and SR-78 Eastbound Ramps
• Twin Oaks Valley Road and Discovery Street/Barham Drive
To verify that the project would not cause or contribute to a violation of the CO standard, a
screening evaluation of the potential for CO “hot spots” was conducted. The Traffic Impact Analysis
evaluated whether or not there would be a decrease in the level of service at the roadways and/or
intersections affected by the Project. The potential for CO “hot spots” was evaluated based on the
results of the Traffic Impact Analysis. The Caltrans ITS Transportation Project-Level Carbon
Monoxide Protocol (Caltrans 1998) should be followed to determine whether a CO “hot spot” is
likely to form due to Project-generated traffic. In accordance with the Protocol, CO “hot spots” are
typically evaluated when (a) the level of service (LOS) of an intersection or roadway decreases to a
LOS E or worse; (b) signalization and/or channelization is added to an intersection; and (c) sensitive
receptors such as residences, commercial developments, schools, hospitals, etc. are located in the
vicinity of the affected intersection or roadway segment.
To evaluate the potential for CO “hot spots,” the procedures in the Caltrans ITS Transportation
Project-Level Carbon Monoxide Protocol were used. As recommended in the Protocol, CALINE4
modeling was conducted for the intersections identified above for the scenario without Project
traffic, and the Project scenarios. Modeling was conducted based on the guidance in Appendix B of
the Protocol to calculate maximum predicted 1-hour CO concentrations. Predicted 1-hour CO
concentrations were then scaled to evaluate maximum predicted 8-hour CO concentrations using
the recommended scaling factor of 0.7 for urban locations.
Inputs to the CALINE4 model were obtained from the Traffic Impact Analysis Report for the Rancho
Coronado Specific Plan (RBF Consulting 2014). As recommended in the Protocol, receptors were
located at locations that were approximately 3 meters from the mixing zone, and at a height of 1.8
meters. Average approach and departure speeds were assumed to be 1 mph to account for
congestion at the intersection and provide a worst case estimate of emissions. Emission factors for
those speeds were estimated from the EMFAC2007 emissions model (ARB 2007) for 2011 for
Existing plus Project conditions, 2020 for Phase II implementation, and 2030 for Phase III
implementation.
In accordance with the Caltrans ITS Transportation Project-Level Carbon Monoxide Protocol, it is
also necessary to estimate future background CO concentrations in the project vicinity to determine
the potential impact plus background and evaluate the potential for CO “hot spots” due to the
project. As a conservative estimate of background CO concentrations, the existing maximum 1-hour
background concentration of CO that was measured at the Escondido monitoring station for the
period 20010 to 2012 of 4.4 ppm was used to represent future maximum background 1-hour CO
Heart of the City Specific Plan Amendment (Rancho Coronado) 36 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
concentrations. This is a conservative assumption, as the monitoring station is located in a
congested area in Escondido. The existing maximum 8-hour background concentration of CO that
was measured at the Escondido monitoring station during the period from 2010 to 2012 of 3.61
ppm was also used to provide a conservative estimate of the maximum 8-hour background
concentrations in the project vicinity. CO concentrations in the future may be lower as inspection
and maintenance programs and more stringent emission controls are placed on vehicles.
The CALINE4 model outputs are provided in Appendix A of the air quality report (Appendix B of this
document). Table 6 presents a summary of the predicted CO concentrations (impact plus
background) for the intersections evaluated. As shown in Table 6, the predicted CO concentrations
would be substantially below the 1-hour and 8-hour NAAQS and CAAQS for CO. Therefore, no
exceedances of the CO standard are predicted, and the project would not cause or contribute to a
violation of this air quality standard.
Table 6. CO Hot Spot Evaluation – Predicted CO Concentrations, ppm
Near Term - 2016
Intersection Existing plus Project
Maximum 1-hour Concentration Plus Background, ppm
CAAQS = 20 ppm; NAAQS = 35 ppm; Background 4.4 ppm
am pm
Twin Oaks Valley Rd./SR-78 EB Ramps 5.3 5.3
Maximum 8-hour Concentration Plus Background, ppm
CAAQS = 9.0 ppm; NAAQS = 9 ppm; Background 3.24 ppm
Twin Oaks Valley Rd./SR-78 EB Ramps 4.24
2020
Maximum 1-hour Concentration Plus Background, ppm
CAAQS = 20 ppm; NAAQS = 35 ppm; Background 4.6 ppm
am pm
Twin Oaks Valley Rd./SR-78 EB Ramps 5.1 5.1
Maximum 8-hour Concentration Plus Background, ppm
CAAQS = 9.0 ppm; NAAQS = 9 ppm; Background 3.54 ppm
Twin Oaks Valley Rd./SR-78 EB Ramps 4.10
2030
Maximum 1-hour Concentration Plus Background, ppm
CAAQS = 20 ppm; NAAQS = 35 ppm; Background 4.4 ppm
am pm
Twin Oaks Valley Rd./SR-78 EB Ramps 4.9 4.9
Twin Oaks Valley Rd./Barham Dr./Discovery St. 4.9 5.0
Maximum 8-hour Concentration Plus Background, ppm
CAAQS = 9.0 ppm; NAAQS = 9 ppm; Background 3.24 ppm
Twin Oaks Valley Rd./SR-78 EB Ramps 3.96
Twin Oaks Valley Rd./Barham Dr./Discovery St. 4.03
Heart of the City Specific Plan Amendment (Rancho Coronado) 37 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
c) Result in a cumulatively considerable net increase of any criteria pollutant for which the
project region is non-attainment under an applicable federal or state ambient air quality
standard (including releasing emissions which exceed quantitative thresholds for ozone
precursors)? Less Than Significant Impact
The San Diego Air Basin is a nonattainment area for the state and federal O3 standards, and for the
state PM10 and PM2.5 standards. Evaluating whether the project could result in a cumulatively
considerable impact on air quality relies on both the project’s consistency with the RAQS and SIP,
which address attainment of the O3 standards, and the potential for the project to result in a
cumulatively considerable impact due to particulate emissions.
As part of the RAQS and SIP planning process, the SDAPCD develops an emission inventory, based on
projections from the San Diego Association of Governments (SANDAG), of growth in the region as
well as on information maintained by the SDAPCD on stationary source emissions within the SDAB.
The SDAPCD then uses the emission inventory to conduct airshed modeling, which provides a
demonstration that the SDAB will attain and maintain the O3 standards. Provided a project’s
emissions are consistent with the projections within the RAQS and SIP, the project would not result
in a cumulatively considerable impact on O3 within the SDAB.
With regard to emissions of O3 precursors NOx and VOCs during construction, the SIP includes
emissions associated with construction in its emissions budget and therefore within its attainment
demonstration. The O3 precursor emissions associated with project construction are well below the
screening level thresholds and are well within the construction emissions budget contained in the
SIP, which includes a demonstration that the SDAB will attain and maintain the O3 standards. Thus
because the project will be consistent with the SIP and therefore consistent with the attainment
demonstration for O3 attainment contained within the SIP, the project would not result in a
cumulatively considerable impact that would cause or contribute to a violation of the O3 standard.
Because the Proposed Project would result in emissions below the significance thresholds for all
nonattainment pollutants, the project would not result in additional emissions of O3 precursors
above that projected in the attainment demonstration for O3. The project will therefore not result
in a cumulatively considerable impact on O3 levels within the SDAB.
No simultaneous major construction projects are anticipated within 100 meters of the project site.
Furthermore, particulate emissions for both construction and operations are below the significance
thresholds. Therefore, no cumulatively considerable PM10 impact would result from construction or
operation of the project. Impacts would be less than significant.
d) Expose sensitive receptors to substantial pollutant concentrations? Less Than Significant
Impact
Sensitive receptors are defined as schools, hospitals, resident care facilities, or day-care centers, as
well as residential receptors in the project vicinity. The threshold concerns whether the project
could expose sensitive receptors to substantial pollutant concentrations, either of criteria pollutants,
or of toxic air contaminants (TACs).
If a project has the potential to result in emissions of any TAC which result in a cancer risk of greater
than 10 in 1 million or substantial non-cancer risk, the project would be deemed to have a
Heart of the City Specific Plan Amendment (Rancho Coronado) 38 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
potentially significant impact. Residential uses are not land uses that would emit substantial
amounts of toxic air contaminants. The truck traffic that would be associated with the construction
activities would be confined to onsite trips to redistribute excavated material and minor on-road
trips to deliver construction materials. Toxic air contaminant impacts would be less than significant.
e) Create objectionable odors affecting a substantial number of people? Less Than Significant
Impact
Project construction could result in minor amounts of odor compounds associated with diesel heavy
equipment exhaust. These compounds would be emitted in various amounts and at various
locations during construction. Odors are highest near the source and would quickly dissipate offsite;
any odors associated with construction would be temporary. Due to the temporary nature of
construction odors and the anticipated dissipation of odors offsite, impacts during construction
would be less than significant.
The project proposes residential and non-residential mixed use development (e.g., office, business
park, retail) and would not include land uses that would be sources of nuisance odors. Thus the
potential for odor impacts associated with the project is less than significant.
IV. BIOLOGICAL RESOURCES
A Biological Technical Report was prepared for the project by Helix Environmental (2014). The
complete report is included as Appendix C of this document. The report provides a description of
biological surveys performed to date, summarizes biological resources present, assesses proposed
impacts to sensitive biological resources, and proposes compensatory mitigation measures for
project impacts.
Biological Resources Background/Habitat Loss Permit
The project site sits within the boundaries of the former Hanson mining site. The eastern and
northern portions of the former Hanson mining site are disturbed from past aggregate mining
activities and the remainder of the site contains undeveloped native habitat. All upland habitat
impacts associated with the mining and the current residential project have been previously
analyzed within the approved Habitat Loss Permit (HLP; HLP 03-08) approved by the City on
December 23, 2003 and approved by the Wildlife Agencies on January 23, 2004.
The project development is proposed in areas that are disturbed from previous mining and cleared
following the initial HLP approval, although some natural jurisdictional areas still remain and will be
impacted. This is analyzed under the biological resources thresholds, below.
The project will be relocating the primary drainage to the west of the existing location, creating a
widened channel bottom and manufactured earthen slopes along both sides that will be restored to
riparian and sage scrub habitat. Overall riparian habitat will be increased over the long term
following restoration. Any impacts to jurisdictional areas will be reviewed and permitted separately
though agency wetland permits.
The HLP authorizes loss of 40.5 acres of coastal sage scrub (CSS) including 0.7 acres of offsite
impacts, 4.5 acres of native grassland (NG), 11.5 acres of eucalyptus woodland, 23.9 acres of
Heart of the City Specific Plan Amendment (Rancho Coronado) 39 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
disturbed habitat, 0.6 acre of ornamental, and 49.5 acres of developed land. Under the HLP the
project was conditioned to preserve 81.0 acres of CSS onsite.
The following project design measures shall be carried forward from the HLP conditions to minimize
impacts to biological resources and are identified as mitigation measures for the project.
Implementation of these mitigation measures will be required as a condition of project approval.
MM-BIO-A The clearing and grubbing of sensitive habitats shall occur outside of the bird
breeding season (February 15 to August 31), unless a qualified biologist
demonstrates to the satisfaction of the City and the Wildlife Agencies that all
nesting is complete. The qualified biologist would need to be federally permitted
for coastal California gnatcatcher if the habitat being cleared has potential to
support these species.
MM-BIO-B Temporary perimeter fencing shall be installed to separate the proposed
development and the fuel management zones from any CSS areas to the preserved
under the HLP. The removal of temporary fencing is only to occur after all clearing
and construction has been completed.
MM-BIO-C Lots adjacent to biological open space will have permanent fencing and no gates
between the development and the open space; (a) landscaping will be restricted to
native and/or non-invasive plant species; and (b) Best Management Practices
(BMPs) during construction in accordance with Nation Pollutant Discharge
Elimination Systems General Construction Permit requirements will be
implemented.
MM-BIO-D A biological monitor will be on-site when habitat is being cleared, and/or
construction activities are occurring within 100 feet of a Biological Open Space
Easement boundary. Permanent signs must be placed every 100 feet along the
fence bordering the preserve. The signs must be corrosion resistant, no less than
three feet above the ground surface, have minimum dimensions of 6” x 9”, and
must state the following:
Sensitive Environmental Resources
Disturbance Beyond this point is Restricted
By Easement
Information:
Contact (Name of Conservancy)
MM-BIO-E A conservation easement shall be placed over all on-site mitigation. Additionally,
the applicant shall insure that the biological open space is deeded to a nature
conservancy acceptable to the planning Division Director for maintenance and
monitoring purposes.
MM-BIO-F Manufactured slopes will be revegetated with appropriate native species in
consultation with the Wildlife Agencies. The landscape plan and construction
documents will be approved by the City Engineer, Planning Director, and Fire
Marshal prior to issuance of building permits.
Heart of the City Specific Plan Amendment (Rancho Coronado) 40 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
MM-BIO-G Any lands providing mitigation/preservation for the project shall be held in
perpetuity in accordance with a habitat management plan to be approved by the
City and the Wildlife Agencies.
a) Have a substantial adverse effect, either directly or through habitat modifications, on any
species identified as a candidate, sensitive, or special status species in local or regional plans,
policies, or regulations, or by the California Department of Fish and Game or U.S. Fish and
Wildlife Service? Less Than Significant with Mitigation Incorporated
Sensitive Plant Species Observed on the Project Site
Focused surveys for sensitive plants within the study area were performed RECON in 2001 and were
verified as part of the HLP process. Sensitive plant surveys were conducted on foot and focused on
those areas supporting native vegetation communities rather than the highly disturbed mining
areas, which supported little vegetation of any kind. Any rare plants that were observed were
mapped on aerial photographs. Two sensitive plant, Wart-stemmed ceanothus and summer holly
was observed during surveys conducted in 2001. See Figure 5 of the Biological Technical Report
(Appendix C of this document) for the location of sensitive species.
Sensitive Animal Species Observed on the Project Site
A total of 34 animal species (including one listed species) were observed/detected within the project
boundaries and include: 46 birds, and 1 mammal species. The only listed species observed is the
coastal California gnatcatcher. Three animal species observed on site are considered sensitive:
coastal California gnatcatcher, yellow warbler, and yellow-breasted chat. The results of most recent
focused surveys for the least Bell’s vireo were negative. See Figure 5 of the Biological Technical
Report (Appendix C of this document) for the location of sensitive species.
Analysis of Direct Impacts to Sensitive Species
No direct take of habitat occupied by the California gnatcatcher will result from project
implementation. Additionally, no impacts to wart-stemmed ceanothus and summer holly would
occur. Impacts would occur to riparian habitat occupied by the yellow warbler and yellow-breasted
chat. These impacts are considered significant (Impact BIO-1). Implementation of mitigation
measures MM-BIO-1A and BIO-1B, which will be required as condition of project approval would
reduce this impact to below a level of significance, as it would creation, enhance and preserve
riparian habitats both on and offsite, which would provide habitat for the yellow warbler and
yellow-breasted chat.
MM-BIO-1A Impacts to 0.23 acre southern riparian forest, 0.15 acre riparian woodland,
1.43 acres southern willow scrub, 0.90 acre freshwater marsh, 0.33 acre mule fat
scrub, and 0.09 SWS/FWM habitat will be mitigated at a 3:1 ratio. Impacts to
0.85 acres disturbed wetland will be mitigated at a 2:1 ratio. Impact to 0.02 acre
streambed will be mitigated at a 1:1 ratio as detailed in Table 7a for a total of
8.89 acres of mitigation. Mitigation includes a combination of onsite and offsite
creation and enhancement with 6.47 acres of creation and 0.30 acres of
enhancement occurring onsite and 1.07 1.27 acres creation mitigation credit
equivalents and 1.05 acres enhancement credits at the North County Habitat Bank.
Heart of the City Specific Plan Amendment (Rancho Coronado) 41 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 7a. Mitigation Requirements for Rancho Coronado (acres)
Vegetation Community Existing Impacts
Required
Mitigation Onsite
Mitigation
Offsite
Mitigation Total Ratio† Area
Riparian woodland (62000) 0.15 0.15 3:1 0.45
6.47
Creation
0.30
Enhancement
1.07
1.27
Creation1
1.05
Enhancement
7.54
7.74
Creation
1.35
Enhancement
Southern riparian forest (61300) 1.72 0.23 3:1 0.69
Southern willow scrub (63320) 1.43 1.43 3:1 4.29
Southern willow scrub/ Freshwater Marsh
(63320/52400) 0.09 0.09 3:1 0.27
Mule fat scrub (63310) 0.33 0.33 3:1 0.99
Freshwater marsh (52400) 0.90 0.16 3:1 0.48
Disturbed wetland (11200) 0.85 0.85 2:1 1.70
Open water (13100) 1.56 0.0 N/A 0
Streambed 0.02 0.02 1:1 0.02
Detention basin (12000) 0.2 0.2 1:1 0.20
7.25 3.46 8.89
9.09 6.77 2.12
8.89
9.09
Notes:
*All areas are presented in acre(s) rounded to the nearest 0.01 **
Riparian habitat creation will be comprised of one or more of the other riparian vegetation communities present on site 10.37 creation credits which is equivalent to 1.071.27 acres of mitigation credit
Heart of the City Specific Plan Amendment (Rancho Coronado) 42 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
MM-BIO-1B The preparation of a riparian restoration plan will be required as a condition of the
mitigation for impacts to riparian vegetation communities. The plan will be require
review and approval by the City and include the following.
• All final specifications and topographic-based grading, planting, and
irrigation plans (0.5-foot contours and typical cross-sections) for the
creation/restoration sites. All wetland mitigation areas shall be graded to
the same elevation as adjacent existing jurisdictional wetlands areas, and/or
to within 1 foot of the groundwater table, and shall be left in a rough grade
state with micro topographic relief (including channels for wetlands) that
mimics natural topography, as directed by the City and Resource Agencies.
All plantings shall be installed in a way that mimics natural plant
distribution, and not in rows;
• Planting palettes (plant species, size, and number/acre) and seed mix (plant
species and pounds/acre). Unless otherwise approved by the City and
Resource Agencies, only locally native species (no cultivars) obtained from
as close to the project area as possible shall be used. The source and proof
of local nativeness of all plant material and seed shall be provided;
• Container plant survival shall be 80 percent of the initial plantings for the
first year;
• A final implementation schedule that indicates when all riparian/wetland
impacts, as well as riparian/wetland creation/restoration grading, planting,
and irrigation, will begin and end. Necessary site preparation and planting
shall be completed during the concurrent or next planting season (i.e., late
fall to early spring). Any temporal loss of habitat caused by delays in
riparian/wetland habitat creation/restoration shall be offset through like
habitat creation/restoration at a 0.5:1 ratio for every 6 months of delay
(i.e., 1:1 for 12 months delay, 1.5:1 for 18 months delay, etc.). In the event
that the project applicant is wholly or partly prevented from performing
obligations under the final plans (causing temporal losses due to delays)
because of unforeseeable circumstances or causes beyond the reasonable
control, and without the fault of negligence of the project applicant,
including but not limited to natural disasters (e.g., earthquakes, etc.), labor
disputes, sudden actions of the elements (e.g., further landslide activity), or
actions or inaction by federal or state agencies, or other governments, the
project applicant will be excused by such unforeseeable cause(s);
• Five years of success criteria for wetland/riparian creation/restoration
areas, including separate percent cover criteria for herbaceous understory,
shrub midstory, and tree overstory, and a total percent absolute cover for
all 3 layers at the end of 5 years; evidence of natural recruitment of multiple
species for all habitat types; 0 percent coverage for Cal-IPC’s “Invasive Plant
Inventory” species, and no more than 10 percent coverage for other
exotic/weed species;
Heart of the City Specific Plan Amendment (Rancho Coronado) 43 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
• A minimum of 5 years of maintenance and monitoring of riparian/wetland
creation/restoration areas, unless success criteria are met earlier and all
artificial water supply has been off for at least 2 years
• A qualitative and quantitative vegetation monitoring plan with a map of
proposed sampling locations. Photo points shall be used for qualitative
monitoring and stratified-random sampling shall be used for all quantitative
monitoring;
• Contingency measures in the event of creation/restoration failure;
• Annual mitigation maintenance and monitoring reports shall be submitted
to the City and Resource Agencies no later than December 1 of each year;
• A wetland delineation shall be done to confirm that USACE and CDFW
jurisdictional wetlands have been successfully created/restored prior to
final approval of creation/restoration sites.
Implementation of mitigation measures MM-BIO-1A and MM-BIO-1B will reduce impacts to
sensitive riparian habitats to below a level of significance.
Migratory Bird Treaty Act (MBTA) Species
Additionally the project has the potential to impact avian species protected under the Migratory
Bird Treaty Act (MBTA) if habitat clearing occurs during the breeding season. This represents a
significant impact (Impact BIO-2). Implementation of mitigation measures MM-BIO-2, which will be
required as a condition of project approval, will reduce this impact to below a level of significance.
MM-BIO-2 Potential direct impacts to bird species covered under the MBTA will be mitigated
by restricting brushing and grading to outside of the breeding season of most bird
species (general breeding season is February 15 to August 31). Grubbing, grading,
or clearing during the breeding season of MBTA covered species could occur if it is
determined via a pre-construction survey that no nesting birds (or birds displaying
breeding or nesting behavior) are present immediately prior to grubbing, grading, or
clearing and will require approval of the City that no breeding or nesting avian
species are present in the vicinity of the grubbing, grading, or clearing. The City
shall be notified of any sensitive bird species identified during the pre-construction
surveys.
Analysis of Indirect Impacts to Sensitive Species
Indirect impacts that may be caused by implementation of the proposed project are associated with
edge effects. Edge effects occur when disturbance, development, or grading traverse an
undeveloped area with substantial native lands surrounding the impact area. Edge effects include
human activity, invasive plant species, nuisance animal species, animal behavioral changes, night
lighting, and roadkill. Additionally, the proposed project has potential to cause temporary indirect
impacts due to noise.
Human Activity − Increases in human activity in an area often result in degradation of sensitive
vegetation by further fragmenting habitat through creation of trails, removal of existing vegetation,
Heart of the City Specific Plan Amendment (Rancho Coronado) 44 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
and illegal dumping (landscape debris, trash, and other refuse). Human activity in the adjacent
habitat is proposed to be controlled by project fencing and monitoring and management
requirements. Still, these impacts would be considered significant (Impact BIO-3). Implementation
of mitigation measures MM-BIO-3, which would be required as a condition of project approval,
would reduce the impact to below a level of significance.
MM-BIO-3 To reduce edge effects, on-site human activity, and potential impacts related to the
introduction of exotic and domestic animals, the biological open space lots shall be
actively managed and monitored. The required habitat management plan (as
detailed in MM-BIO-1B) shall ensure that access be restricted to developed areas.
Permanent fencing shall be provided for all backyards abutting proposed project
open space. In addition, preserved habitat shall be posted with signs precluding
access due to habitat sensitivity and prohibiting dumping. Residents shall be
educated in access restrictions, control of domestic animals, prevention of irrigation
runoff, and sensitivity of habitats on site.
Invasive Plants − Invasive plants have potential to spread from developed or disturbed areas to
adjacent native habitats. Such invasive species can displace native vegetation reducing the diversity
of native habitats and potentially increasing flammability, changing ground and surface water levels,
and adversely affecting native wildlife. As a project design feature, no invasive plant species would
be utilized in the landscaping plans, and no species on the Cal-IPC “Invasive Plant Inventory” list shall
be included in the erosion control plan. These design features are included in Table 2. Therefore
impacts would be less than significant.
Nuisance Animal Species − Domesticated animals, particularly cats, are known to impact native
wildlife in the habitat areas immediately adjacent to development. The proposed project has the
potential to result in introduction of domestic animals to the surrounding habitat. Project fencing
and the maintenance of healthy predator populations (coyote and bobcat) will minimize
introduction of domestic animals. Brown-headed cowbirds are an invasive nest parasite that can
greatly reduce the breeding success of native birds. This species has been reported on site and on
the adjacent property to the west in low numbers, and the proposed project is not expected to
significantly increase the number of brown-headed cowbirds in the surrounding habitat. In addition,
residential uses may introduce Argentine ants to local habitats, which could have significant
consequences for native ant species and animals that feed on them. Impacts from Argentine ants
will be avoided by requiring the inspection of all plant material prior to use on the site. This
requirement is identified as a project design features (Table 2). Therefore, impacts associated with
nuisance animal species are expected to be adverse but less than significant.
Night Lighting − Night lighting exposes wildlife species to an unnatural light regime and may alter
their behavior patterns, causing them to have lower reproductive success, and thus reducing species
diversity. All exterior lighting adjacent to preserved habitat including street lighting for Street A
shall be limited to low pressure sodium sources of the lowest illumination allowed for human safety,
selectively placed, shielded, and directed away from preserved habitat to the maximum extent
practicable. This requirement is identified as a project design features (Table 2). Therefore, impacts
due to night lighting would be considered less than significant.
Roadkill − Roadkill impacts would be considered significant if they resulted in adverse effects to
federally or state listed species. Roadkill could occur as vehicles travel on the internal roads
Heart of the City Specific Plan Amendment (Rancho Coronado) 45 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
associated with the project. The primary drainage through the site may currently provide minimal
local wildlife movement through the project site, though the site is highly disturbed with mining
activities. The preserve over the southern portion of the site is completely avoided and connects
with offsite preserve areas, and the restored channel will include an arch culvert under the access
road to the proposed park to facilitate wildlife movement. Therefore, on-site roadkill impacts are
anticipated to be less than significant.
Noise − Noise from grading, grubbing, and vehicular traffic would be a temporary impact to local
wildlife. Noise impacts would be considered significant if sensitive species, such as the coastal
California gnatcatcher or raptor species were displaced and failed to breed. Breeding mammals and
birds may temporarily leave the project vicinity during construction activities; however, they would
be expected to return afterward once the noise impact has been eliminated because the habitat will
remain in place and viable for reoccupation by the displaced species. Noise levels during grading at
the grading/open space interface throughout the site would be in excess of 60 dBA Leq. Such noise
impacts to nesting coastal California gnatcatchers would be considered significant (Impact BIO-4).
Implementation of mitigation measures MM-BIO-4, which will be required as a condition of project
approval will reduce this potential impact to below a level of significance.
MM-BIO-4 If project grading (other than clearing and grubbing of sensitive habitats) is
necessary and adjacent to preserved on-site habitat during the bird breeding season
(February 15 to August 31), a qualified biologist shall conduct pre-construction
surveys in the adjacent habitat for the coastal California gnatcatcher\ and nesting
raptors. The survey shall begin not more than three days prior to the beginning of
grading activities. The Wildlife Agencies shall be notified if the gnatcatcher is
observed nesting within 300 feet of proposed grading or if raptors are observed
nesting within 500 feet of proposed grading activities. No activities which would
result in noise levels exceeding 60 dBA hourly Leq within this buffer shall be allowed.
If grading activities are not initiated prior to the breeding season, and any of these
species are present, and noise levels exceed this threshold, noise barriers shall be
erected to reduce noise impacts to occupied habitat to below 60 dBA hourly Leq
and/or the activities shall be suspended. Impacts resulting from noise for non-listed
species other than raptors are not considered significant, and mitigation is not
warranted.
b) Have a substantial adverse effect on any riparian habitat or other sensitive natural community
identified in local or regional plans, policies, regulations, or by the California Department of
Fish and Game or U.S. Fish and Wildlife Service? Less Than Significant with Mitigation
Incorporated
Direct Impact to Riparian Habitats
Implementation of the proposed project would result in impacts to wetland resources, including
0.23 acre of southern riparian forest, 0.15 acre of riparian woodland, 1.43 acre of southern willow
scrub, 0.16 acre of freshwater marsh (SWS/FWM), 0.33 acre of mule fat scrub, and 0.09 acre of
southern willow scrub/freshwater marsh habitat, 0.85 acre of disturbed wetland, as well as 0.02
acre of streambed, and 0.19 acre detention basin (Table 7b). These impacts are considered
significant (Impact BIO-5).
Heart of the City Specific Plan Amendment (Rancho Coronado) 46 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 7b. Summary of Impact to Vegetation Communities
Vegetation Community
Existing
(acres)
Impacts
(acres)
Proposed
HLP Preserve
(acres)
Southern riparian woodland (62000) 0.15 0.15 0.0
Southern riparian forest (61300) 1.72 0.23 0.70(1)
Southern willow scrub (63320) 1.43 1.43 0.0
Southern willow scrub/Freshwater Marsh
(63320/52400) 0.09 0.09 0.0
Mule fat scrub (63310) 0.33 0.33 0.0
Freshwater marsh (52400) 0.90 0.16 0.0
Disturbed wetland (11200) 0.85 0.85 0.0
Open water (13100) 1.56 0.0 0.0
Streambed 0.02 0.02 0.0
Diegan coastal sage scrub (32500) 92.6 0.0 91.4
Southern mixed chaparral (37120) 11.5 0.0 11.5
Eucalyptus woodland (79000) 7.9 5.4 3.2
Disturbed habitat (11300) 132.0 86.9 3.4
Detention basin (12000) 0.2 0.2 0.0
Total 251.2 95.7 110.0(2)
Notes:
(1) Does not include 1.0 acres that will also be preserved within the riparian mitigation area.
(2) Does not include additional acres conserved as part of wetland restoration onsite.
Implementation of mitigation measures MM-BIO-1A and MM-BIO-1B would reduce impact to
riparian habitats to below a level of significance since it would create and enhance riparian habitats
both on and offsite.
Direct Impact to Upland Habitat
No sensitive upland habitat impacts are anticipated. All sensitive upland habitats are located within
the existing HLP preserve area. Minor adjustments to the HLP preserve are proposed but there are
no impacts associated with the adjustment other than to disturbed habitat. These impacts are not
considered significant.
Indirect Impact to Sensitive Habitats
Indirect impacts that may be caused by implementation of the proposed project are associated with
edge effects. Edge effects occur when disturbance, development, or grading traverse an
undeveloped area with substantial native lands surrounding the impact area. Edge effects for
sensitive habitats include decreased water quality and temporary indirect impacts due to noise and
fugitive dust.
Water Quality – Landscaping often results in increased runoff, which could in turn reduce water
quality in riparian areas. The use of petroleum products (i.e., fuels, oils, lubricants) and erosion of
land cleared during mine reclamation could potentially contaminate surface water, adversely
affecting vegetation, aquatic animals, and terrestrial wildlife. However, implementation of BMPs
per the City’s grading permitting requirements, as well as installation of drainage and desiltation
Heart of the City Specific Plan Amendment (Rancho Coronado) 47 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
basins outlined in the Stormwater Management Plan would reduce potential short-term water
quality impacts to below a level of significance. These requirements are included as project design
features (Table 2).
During construction, measures would be implemented as part of the project to control erosion,
sedimentation, and pollution that could impact water resources on and off site. Prior to the
commencement of grading, a Notice of Intent must be filed with the RWQCB for a National Pollutant
Discharge Elimination System General Construction Storm Water Permit. Specific permit
requirements include implementation of an approved Storm Water Pollution Prevention Plan, which
requires best management practices for erosion and sediment control related to construction
activities. Standard measures that may apply to the proposed project include:
• Surface drainage will be designed to collect and move runoff into adequately sized drainage
structures before being discharged into natural stream channels.
• Erosion control measures associated with the project will include techniques for both long-
and short-term erosion hazards. These include such measures as the short-term use of
gravel bags, matting, mulches, berms, hay bales, or similar devices along all pertinent
graded areas to minimize sediment transport.
• Native vegetation will be preserved whenever feasible, and all disturbed areas will be
stabilized as soon as possible after completion of grading.
• Use of energy dissipating structures (e.g., detention ponds, riprap, or drop structures) will
be used at storm drain outlets, drainage crossings, and/or downstream of all culverts, pipe
outlets, and brow ditches to reduce velocity and prevent erosion.
• A maintenance plan for temporary erosion control facilities will be established. This
typically involves inspection, cleaning, and repair operations being conducted after runoff-
producing rainfall.
• Removal and disposal of ground water (if any) encountered during construction activities
will be coordinated with the RWQCB to ensure proper disposal methods and locations under
a General Dewatering Permit if required. This may involve specific measures such as
removing excess sediment (through the use of desilting basins, etc.) and limiting discharge
velocity.
• Specified fueling and maintenance procedures will be designated to preclude the discharge
of hazardous materials used during construction (e.g., fuels, lubricants, and solvents). Such
designations will include specific measures to preclude spill including proper handling and
disposal techniques.
Further, the project shall comply with the latest NPDES permit (Order No. R9-2013-0001) as well as
the latest City of San Marcos’ Storm Water Standards Manual Guidelines. A WQIP shall be approved
by the City prior to issuance of any grading permit and shall address how the pollutants of concern
will be treated, how low impact development standards will be satisfied and how hydromodification
requirements will be achieved. .
Fugitive Dust – Dust released during grading activities could cover vegetation in adjacent habitat
areas. The resulting dust-induced shading could reduce native plant productivity, in turn displacing
native vegetation, reducing diversity, encouraging weed invasion, adversely affecting wildlife, and
Heart of the City Specific Plan Amendment (Rancho Coronado) 48 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
increasing fire susceptibility. One of the project design measures requires that the monitoring
biologist periodically monitor adjacent habitats for excessive amounts of dust, and recommend
remedial measures to address dust control if necessary. This requirement is included as a project
design feature (Table 2). As a result, the effects of dust on surrounding vegetation are considered
less than significant.
c) Have a substantial adverse effect on federally protected wetlands as defined by Section 404 of
the Clean Water Act (including, but not limited to, marsh, vernal pool, coastal, etc.) through
direct removal, filling, hydrological interruption, or other means? Less Than Significant with
Mitigation Incorporated
A delineation of on-site jurisdictional areas was performed by HELIX in 2012. All areas with
depressions, drainage channels, or wetland vegetation were evaluated for the presence of U.S.
Army Corps of Engineers (USACE) and California Department of Fish and Wildlife (CDFW)
jurisdictional wetlands, as well as Waters of the U.S. (WUS) and CDFW streambeds in accordance
with applicable guidelines.
Within the study area, USACE jurisdictional areas occur along the primary drainage along the
eastern boundary and in the northern portion of the site. Additional jurisdictional areas occur in the
south-central portion of the site. Federal (USACE) jurisdictional areas on the project site include
1.39 acres of wetland and 0.46 acre of non-wetland WUS. See Figure 6 in Biological Technical Report
(Appendix C of this document) for the location of the USACE jurisdictional areas. State (CDFW)
jurisdictional areas on the project site include 4.83 acres of wetland and 0.07 acre of non-wetland
See Figure 7 in Biological Technical Report (Appendix C of this document) for the location of the
CDFW jurisdictional areas.
The project would cause permanent and temporary impacts to both USACE and CDFW jurisdictional
areas. The project would permanently impacts to 1.32 acre of USACE jurisdictional areas and 3.45
acres of CDFW jurisdictional areas (Table 8). See Figures 10 and 11 in Biological Technical Report
(Appendix C of this document) for the location of the impact areas. This represents a significant
impact (Impact BIO-6).
Impacts to all on-site WUS (including wetlands) are regulated by the USACE under Section 404 of the
Clean Water Act (33 USC 1344) and would require a USACE permit. Implementation of the project
will result in impacts greater than 0.5 acre and an Individual Permit would be necessary. Individual
permits require a biological assessment, a detailed Section 404(b) alternatives analysis, an
environmental assessment, and preparation of a mitigation and monitoring plan. A State Water
Resources Control Board (SWRCB) permit (401 Certification) is required under the Clean Water Act
in association with the 404 Permit.
The CDFW is also responsible for issuing permits for impacts to streambeds and wetlands under its
jurisdiction. Any impacts to CDFW jurisdictional areas are regulated under California Fish and Game
Code Section 1602 and will require a Streambed/Lake Alteration Agreement.
Heart of the City Specific Plan Amendment (Rancho Coronado) 49 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 8. USACE and CDFW Jurisdictional Impacts
Vegetated Habitat1
Habitat USACE2 CDFW
2
Southern riparian woodland 0.0 0.15
Southern riparian forest 0.05 0.23
Southern willow scrub 0.12 1.43
Southern willow scrub/freshwater marsh 0.09 0.09
Freshwater marsh 0.16 0.16
Mule fat scrub 0.02 0.33
Disturbed wetland 0.43 0.89
Subtotal 0.87 3.28
Unvegetated Habitat
Habitat USACE CDFW
Streambed 0.38 0.10
Detention Basin 0.07 0.07
Subtotal 0.45 0.17
TOTAL 1.32 3.45
Notes: 1Acreage is rounded to the nearest hundredth.
2All impacts are permanent. There are no temporary impacts.
The USACE and CDFW all require no net loss of wetlands, a policy under which mitigation occurs at a
minimum ratio of 1:1 with a combination of creation and restoration. The project includes relocating
the primary drainage to the west of the existing location, creating a widened channel bottom and
manufactured earthen slopes along both sides. Riparian vegetation is to be installed in the channel
bottom; the riparian edge will be planted with coast live oak woodland and the slopes are to be
planted with Diegan coastal sage scrub vegetation. Implementation of mitigation measures MM-
BIO-1A and MM-BIO-1B would reduce impact to jurisdictional habitat and unvegetated waters to
below a level of significance since it would create and enhance riparian habitats both on and offsite
and offset impacts to jurisdictional wetland and waters.
d) Interfere substantially with the movement of any native resident or migratory fish or wildlife
species or with established native resident or migratory wildlife corridors, or impede the use
of native wildlife nursery sites? Less than Significant Impact
The northern and eastern portions of the site are highly disturbed by previous mining activities and
do not function as local wildlife corridors. The native habitat in the southwestern portion of the site
provides live in habitat for wildlife and may also serve as a local corridor along the drainage in the
south-central portion of the site. The primary drainage is within the eastern and north-central
portion of the site, and originates from runoff from South Twin Oaks Valley Road, as well as recent
development east of Twin Oaks Valley Road. The runoff flows westerly through the property and
into Discovery Lake, which is situated immediately off site to the west. The onsite drainage has
been heavily degraded by the quarry operation over the years. Wildlife movement is most likely to
occur to and from the western portion of the site to the undeveloped lands to the west, east and
south. There are no regional corridors that traverse the site and the project lies outside of the
Biological Resource Conservation Area for the Multiple Habitat Conservation Plan. Regional
connectivity occurs to the south of the project.
Heart of the City Specific Plan Amendment (Rancho Coronado) 50 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
The proposed open space occurs in the southwestern portion of the site and abuts existing open
space to the southwest and South Lake to the south. The small block of open space in the southern
corner of the site also is adjacent to existing open space located on the other side of Twin Oaks
Valley Road. Proposed restoration of the creek through the project will connect preserve lands in
the southwestern portion of the site with Discovery Lake immediately northwest of the site. The
drainage will maintain wildlife connectivity through these areas by providing a restored creek
channel with riparian habitat and upland buffer habitat, and by providing an arch culvert for wildlife
movement under the access road to the proposed park. Because the site is currently heavily
disturbed, wildlife movement may actually be enhanced along the creek channel. The
approximately 11 acres of open space along the restored creek channel will add to the regional
preserve in this area. Therefore impacts to regional conservation or wildlife movement are
anticipated and impact would be less than significant.
e) Conflict with any local policies or ordinances protecting biological resources, such as a tree
preservation policy or ordinance? No Impact
The proposed project would not conflict with any local policies or ordinances protection biological
resources, such as a tree preservation policies or ordinance. The project meets the requirements of
the existing HLP for the project site and includes habitat conservation as well as habitat creation and
enhancement. No impact is identified for this issue area.
f) Conflict with the provisions of an adopted Habitat Conservation Plan, Natural Community
Conservation Plan, or other approved local, regional, or state habitat conservation plan? No
Impact
The project site is located outside of the Biological Resource Conservation Area for the Multiple
Habitat Conservation Plan. Therefore the project would not conflict with the provisions of an
adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local,
regional, or state habitat conservation plan and no impact is identified.
V. CULTURAL RESOURCES
A Cultural Resources Report was prepared for the project by ASM Affiliates (2013) and is included in
Appendix D.
a) Cause a substantial adverse change in the significance of a historical resource as defined in
§15064.5? No Impact
A cultural resources report has been prepared for the project site by ASM Affiliates (2013) and is
included in Appendix D. The report presents the results of a cultural and historical resources
inventory conducted within the Area of Potential Effect for the proposed project. Site records on file
at the South Coastal Information Center (SCIC), San Diego State University, indicate 21 previous
archaeological surveys have been conducted within the one-mile search radius of the proposed
project. The report concluded that no cultural resources had been previously recorded within the
APE, and no new resources were recorded during the survey. No cultural resources have been
previously recorded within the search radius. Additionally, the pedestrian survey conducted by ASM
did not identify any historical resources on the site. Therefore, no impact is identified for this issue
area.
Heart of the City Specific Plan Amendment (Rancho Coronado) 51 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
b) Cause a substantial adverse change in the significance of an archaeological resource pursuant
to §15064.5? Less Than Significant with Mitigation Incorporated
Based upon the cultural resources reports prepared for the project (ASM Affiliates 2013), no
archeological resources are known to occur on the project site. ASM’s research included a records
research and site reconnaissance.
Site records on file at the SCIC indicated 21 previous archaeological surveys have been conducted
within a one-mile radius of the proposed project. None of the previous surveys identified or
recorded archaeological resources within the current project boundary. Additionally, the pedestrian
survey conducted by ASM did not identify any historical resources on the site. A Sacred Lands File
Search was conducted by the Native American Heritage Commission (NAHC) and did not identify any
sacred sites in the project area).
Although ASM did not identify the potential for archeological or Native American resources, one of
the tribes (Rincon Band) consulted during the preparation of the Cultural Resources Analysis for the
proposed project, did note the potential to encounter unidentified resources during the grading
activities and requested that monitoring be conducted during the grading operation (Impact CR-1).
Correspondence from the Pala Band was received but noted that the project site was outside their
Traditional Use Area. Correspondence from the San Luis Rey Band requested a copy of the cultural
resources report once it was completed.
As the City does not have access to all tribal sacred land site records, the City will include as a
component of the project activities the presence of an Archeological monitor and a Native American
monitor during the earth moving grading activities to assure that any resources found during project
grading would be protected as directed by the Most Likely Decedent (MLD). Therefore, impacts are
less than significant with incorporation of mitigation measure MM-CR-1 through MR-CR-8.
Implementation of MM-CR-1 through MM-CR-8 shall be required as a condition of project approval
and will reduce potential impacts to below a level of significance.
MM-CR-1 An archeological monitor and a Luiseño Native American monitor shall be present
during the all earth moving and grading activities to assure that any potential
cultural resources, including tribal, found during project grading be protected.
MM CR-2 Prior to beginning project construction, the Project Applicant shall retain a San
Diego County qualified archaeological monitor to monitor all ground-disturbing
activities in an effort to identify any unknown archaeological resources. Any newly
discovered cultural resource deposits shall be subject to cultural resources
evaluation, which shall include archaeological documentation, analysis and report
generation.
MM-CR-3 At least 30 days prior to beginning project construction, the Project Applicant shall
enter into a Cultural Resource Treatment and Monitoring Agreement (also known as
a pre-excavation agreement) with a Luiseño Tribe. contact the Rincon Tribe to
notify the Tribe of grading, excavation and the monitoring program and to develop a
Cultural Resources Treatment and Monitoring Agreement. The Agreement shall
address the treatment of known cultural resources, the designation, responsibilities,
and participation of professional Native American Tribal monitors during grading,
Heart of the City Specific Plan Amendment (Rancho Coronado) 52 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
excavation and ground disturbing activities; project grading and development
scheduling; terms of compensation for the monitors; and treatment and final
disposition of any cultural resources, sacred sites, and human remains discovered
on site.
MM-CR-4 Prior to beginning project construction, the Project Archaeologist shall file a pre-
grading report with the City to document the proposed methodology for grading
activity observation, which will be determined in consultation with the Luiseño Tribe
referenced in MM-CR-3. the Rincon Tribe. Said methodology shall include the
requirement for a qualified archaeological monitor to be present and to have the
authority to stop and redirect grading activities. In accordance with the agreement
required in MM-CR-3, the archaeological monitor’s authority to stop and redirect
grading will be exercised in consultation with the Luiseño Native American monitor
the Rincon Tribe in order to evaluate the significance of any archaeological
resources discovered on the property. Tribal and archaeological monitors shall be
allowed to monitor all grading, excavation, and groundbreaking activities, and shall
also have the authority to stop and redirect grading activities.
MM-CR-5 The landowner shall relinquish ownership of all cultural resources, including sacred
items, burial goods, and all archaeological artifacts that are found on the project
area collected during the grading monitoring program and from any previous
archaeological studies or excavations on the project site to the appropriate Tribe for
proper treatment and disposition per the Cultural Resource Treatment and
Monitoring Agreement referenced in MM-CR-3. All cultural materials that are
deemed by the Tribe to be associated with burial and/or funerary goods will be
repatriated to the Most Likely Descendant as determined by the Native American
Heritage Commission per California Public Resources Code Section 5097.98.
In the event that curation of cultural resources is required, curation shall be
conducted by an approved facility and the curation shalll be guided by California
State Historic Resource Commissions Guidelines for the Curation of Archaeological
Collections. The City of San Marcos shall provide the developer final curation
language and guidance on the project grading plans prior to issuance of the grading
permit, if applicable, during project construction.
collected during the grading monitoring program and from any previous
archaeological studies or excavations on the project site, with the exception of
sacred items, burial goods, and human remains which will be addressed in the
Treatment Agreement required in MM-CR-3, shall be tribally curated according to
the current professional repository standards by the Rincon Tribe. The collections
and associated records shall be transferred, including title, to the Rincon Tribe.
MM-CR-6 All sacred sites, should they be encountered within the project area, shall be
avoided and preserved as the preferred mitigation, if feasible.
MM-CR-7 If human remains are encountered, California Health and Safety Code Section
7050.5 states that no further disturbance shall occur until the San Diego County
Coroner has made the necessary findings as to origin. Further, pursuant to California
Heart of the City Specific Plan Amendment (Rancho Coronado) 53 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Public Resources Code Section 5097.98(b) remains shall be left in place and free
from disturbance until a final decision as to the treatment and disposition has been
made. Suspected Native American remains shall be examined in the field and kept in
a secure location at the site If the San Diego County Coroner determines the
remains to be Native American, the Native American Heritage Commission (NAHC)
must be contacted within 24 hours. The NAHC must them immediately notify the
“most likely descendant(s)” of receiving notification of the discovery. The most likely
descendants(s) shall then make recommendations within 48 hours, and engage in
consultation concerning treatment of remains as provided in Public Resources Code
5097.98, and the Treatment Agreement described in MM-CR-.3.
MM-CR-8 If inadvertent discoveries of subsurface archaeological/cultural resources are
discovered during grading, the Developer, the project archaeologist, and the
Luiseño Tribe under agreement with the landowner described in MM-CR-3 shall
assess the significance of such resources and shall meet and confer regarding the
mitigation for such resources. Pursuant to California Public Resources Code Section
21083.2(b) avoidance is the preferred method of preservation for archaeological
resources. If the Developer, the project archaeologist and the Tribe cannot agree on
the significance of mitigation for such resources, these issues will be presented to
the Planning Director for decision. The Planning Director shall make a determination
based upon the provisions of the California Environmental Quality Act with respect
to archaeological resources and shall take into account the religious beliefs,
customs, and practices of the Tribe. Notwithstanding any other rights available
under law, the decision of the Planning Director shall be appealable to the Planning
Commission and/or City Council.
c) Directly or indirectly destroy a unique paleontological resource or site or unique geologic
feature? Less Than Significant Impact
The project area is located in the Peninsular Ranges Geomorphic Province, underlain by Santiago
Peak Volcanics. In general, the molten origin of the Santiago Peak Volcanics precludes the discovery
of fossil remains. Therefore, due to the limited availability of fossil-producing geologic formations,
impacts due to this issue area are considered less than significant.
d) Disturb any human remains, including those interred outside of formal cemeteries? Less Than
Significant With Mitigation Incorporated
The cultural resource assessment prepared by ASM Affiliates (2013) did not indicate the likelihood
of human remains on the site. Additionally, existing regulations, through California Health and
Safety Code Section 7050.5 state that if human remains are discovered during project construction,
no further disturbance shall occur until the San Diego County Coroner has made the necessary
findings as to origin. Further, pursuant to California Public Resources Code Section 5097.98(b)
remains shall be left in place and free from disturbance until a final decision as to the treatment and
disposition has been made. If the San Diego County Coroner determines the remains to be Native
American, the Native American Heritage Commission shall be contacted within a reasonable
timeframe. Subsequently, the Native American Heritage Commission shall identify the “most likely
descendant.” The Most Likely Descendant shall then make recommendations, and engage in
consultations concerning the treatment of the remains as provided in Public Resources Code
Heart of the City Specific Plan Amendment (Rancho Coronado) 54 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
5097.98. So, while the cultural resources assessment concluded that there is no evidence of human
remains on the project site, a Sacred Lands monitor shall be present during the earth moving
grading activities to assure that any resources found during project grading would be protected as
directed by the MLD. Therefore, impacts are less than significant with incorporation of mitigation
measures MM-CR-1 through MM-CR-8.
VI. GEOLOGY AND SOILS
a) Expose people or structures to potential substantial adverse effects, including the risk of loss,
injury, or death involving:
i) Rupture of a known earthquake fault, as delineated on the most recent Alquist-Priolo
Earthquake Fault Zoning map, issued by the State Geologist for the area or based on other
substantial evidence of a known fault? Refer to Division of Mines and Geology Special
Publication 42. No Impact
The project site is located within a seismically active region, as is all of Southern California.
However, the project site is not adjacent to any known active faults. The project site is not
located on a fault, as delineated by the most recent Alquist-Priolo Earthquake Fault Zoning Map
(Department of Conservation, 2008). The closest major active faults are the Elsinore fault,
located 15 miles to the northeast, and the Coronado Banks fault located offshore approximately
25 miles to the southwest. The Rose Canyon fault, which is potentially active, is located
approximately 11 miles southwest of the project site. Therefore, no impact is identified for this
issue area.
ii) Strong seismic ground shaking? Less Than Significant Impact
The proposed project is located in seismically-active Southern California and is considered likely
to be subjected to strong ground motion from regional seismic activity. As identified in Section
VI.a.i, the nearest identified potentially active fault is located approximately 11 miles from the
project area. All structures on the site would be designed in accordance with seismic parameters
of the California Building Code (2007). Therefore, the impact for this issue area would be
considered less than significant.
iii) Seismic-related ground failure, including liquefaction? No Impact
The project site is located within the coastal sub-province of the Peninsular Ranges Geomorphic
Province, and is underlain by metavolcanic rock of the Cretaceous to Jurassic-aged Santiago
Peak Volcanics. Leighton Consulting (2012) (Appendix E) conducted a limited geotechnical
exploration for the proposed San Marcos Elementary School at Rancho Coronado project
located in San Marcos, California. Based on the results of this exploration, the report concluded
that the proposed site improvements are feasible provided the geotechnical recommendations
contained in this report are implemented during design and construction (Impact GS-1).
Therefore, the impacts due to ground failure and liquefaction are considered less that
significant.
iv) Landslides? Less Than Significant Impact
Land sliding and slope instability in San Marcos is associated with bedding plane faults, weak
Heart of the City Specific Plan Amendment (Rancho Coronado) 55 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
claystone and siltstone beds associated with Eocene sedimentary rocks. The community plan
areas of Barham/Discovery and Questhaven/La Costa Meadows have scattered sites known for
slope instability in hillside areas, however the project area consists of Exchequer series of soils.
These soils are formed in material weathered from hard metabasic rock, consisting of shallow to
very shallow, well-drained silt loams, located on mountainous uplands, and are not conducive to
landslides. In addition, on December 2, 2011, the reclamation plan submitted by Hanson was
approved for construction and a grading permit was issued on December 7, 2011. The grading
work took place between February and April 2012 on the proposed school site has resulted in
the establishment of stabilized 2:1 slopes or less. Therefore, no impact is identified for this issue
area.
b) Result in substantial soil erosion or the loss of topsoil? Less than Significant Impact
On December 2, 2011, the reclamation plan submitted by Hanson was approved for construction
and a grading permit was issued on December 7, 2011. The General Construction Permit (GCP) that
will be required of the project and the existing General Industrial Permit (GIP) for the project site
require BMPs for sediment control and erosion during construction activities or activities conducted
under the SWPPP. These BMPs are required and will mitigate soil loss and erosion.
The grading work took place between February and April 2012 and resulted in the establishment of
stabilized 2:1 slopes or less.
The project would be required to be under the GCP which requires the preparation of a SWPPP and
development of BMPs for all phases of construction. The GCP would result in stabilization of all
graded areas prior to the completion of the graded portions of the project.
The project would grade portions of the site and prepare the site for development of the residential,
mixed-use non-residential and active park uses as well as supporting roadways and infrastructure.
Grading operations could have the potential to expose bare slopes which could result in soil erosion
and loss of topsoil. However, the project would be required by the SWRCB GCP to obtaining
stabilization and incorporate erosion and sediment control measures during and after grading
operations. See Table 2 for a list of project design feature BMPs related to this topic. These BMPs
will be included in the SWPPP and in the construction plans and specifications which and shall be
implemented during construction. The GCP prohibits sediment or pollutant release from the project
site. Further all slopes will be required to be stabilized with permanent vegetation. Therefore,
impacts would be less than significant.
c) Be located on a geologic unit or soil that is unstable, or that would become unstable as a
result of the project, and potentially result in on- or off-site landslide, lateral spreading,
subsidence, liquefaction or collapse? Less than Significant Impact
See comments VI.a.1 and VI .a.2.
d) Be located on expansive soil, as defined in Table 18-1-B of the Uniform Building Code (1994),
creating substantial risks to life or property? Less Than Significant Impact
The Preliminary Geotechnical Report and Addendum prepared by Leighton Consulting (2012) found
that the onsite soils are expected to have a low to moderate expansion potential, but concluded
Heart of the City Specific Plan Amendment (Rancho Coronado) 56 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
that the project is feasible. A final geotechnical analysis would be performed to determine the actual
expansion potential of finish grade soils and recommendations in light of proposed building designs.
The final geotechnical analysis would ensure that the site soils are properly prepared so that any
potential expansion issues would be remedied. Therefore, impacts would be less than significant.
e) Have soils capable of adequately supporting the use of septic tanks or alternative wastewater
disposal systems where sewers are not available for the disposal of wastewater? No Impact
The project does not propose any septic tanks or alternative wastewater disposal systems.
Therefore, no impact is identified for this issue area.
VII. GREENHOUSE GAS EMISSIONS
A global climate change assessment was prepared for the project by Scientific Resources Associated
(2014b). The complete report is included as Appendix F of this document.
a) Generate greenhouse gas emissions, either directly or indirectly, that may have a significant
impact on the environment? Less Than Significant Impact
Existing Greenhouse Gas Emissions (GHG)
The site has historically been used for extraction of aggregate materials. The project is located
within the southwestern portion of the Heart of the City Specific Plan. The project site property is
bounded by Twin Oaks Valley Road on the east, the Discovery Hills residential community on the
north, and undeveloped land on the west and south, in the Barham/Discovery Hills neighborhood.
In its past use for extraction of aggregate materials, the site was a source of GHG emissions from the
use of equipment to extract materials and truck traffic to transport materials from the site.
GHG emissions associated with the Rancho Coronado Specific Plan were estimated separately for
four categories of emissions: (1) construction; (2) energy use, including electricity and natural gas
usage; (3) water consumption; and (4) transportation. The analysis includes a baseline estimate
assuming Title 24-compliant buildings, which is considered business as usual for the proposed
Project. Emissions were estimated based on emission factors from the California Climate Action
Registry General Reporting Protocol (CCAP 2008). This inventory presents emissions based on
“business as usual” assumptions.
Construction GHG Emissions
Construction GHG emissions include emissions from heavy construction equipment, truck traffic,
and worker trips. Emissions were calculated based on the CalEEMod Model (ENVIRON 2011). Total
GHG emissions associated with construction are estimated at 7,245 metric tons of CO2e. To
evaluate construction projects’ contribution to overall annual GHG emissions, the SCAQMD
recommends in their interim guidance for evaluating GHGs under CEQA (SCAQMD 2008). For
construction emissions, the interim guidance recommends that the emissions be amortized over 30
years and added to operational emissions, as appropriate. Amortized over 30 years, construction
would contribute 240 metric tons per year of CO2 emissions.
Operational GHG Emissions
Heart of the City Specific Plan Amendment (Rancho Coronado) 57 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
The proposed project includes 346 residential units, 24 acres of non-residential mixed use,
approximately 38 acres of active park and the necessary infrastructure to support the proposed
development. Total electricity, natural gas, and water usage rates for the residences and commercial
development under “business as usual” conditions were estimated as discussed in the sections
below.
Energy Use Emissions – As discussed above, energy use generates GHG through emissions from
power plants that generate electricity, as well as emissions from natural gas usage at the facility
itself.
Business as usual electricity use was estimated based on construction of the proposed Project to
meet the requirements of Title 24 as of 2005. As stated in Section 3.0, based on the latest
guidelines and baseline emission calculations for energy efficiency, “business as usual” is considered
to be the equivalent of Title 24 as of 2005 because the ARB’s baseline inventory and its definition of
business as usual is based on compliance with Title 24 as of 2005. The ARB prepared its inventory to
evaluate the required reduction from “business as usual,” which is defined as the baseline with no
measures implemented to reduce emissions of GHGs. For building standards, the goal of reducing
emissions below business as usual within the ARB’s Scoping Plan is based on Title 24 as of the ARB’s
inventory. Thus, the baseline used in this analysis is consistent with the ARB’s analysis and goals.
The use of Title 24 as of 2005 is consistent with the Scoping Plan. The Scoping Plan is the original
basis for the County’s approach to evaluating significance of impacts for GHG emissions. The County
based its goals for reduction of emissions from “business as usual” levels on the Scoping Plan. It is
therefore appropriate to use the baseline energy use contained in the Scoping Plan as the baseline
for evaluating emissions for individual projects within the County. As stated above, Title 24 as of
2005 was the baseline used in the ARB’s Scoping Plan.
Emissions were calculated based on emission factors in the California Climate Action Registry
General Reporting Protocol, Version 3.1 (CCAR 2009).
Natural gas use was also estimated based on construction of the proposed Project to meet the
requirements of Title 24 as of 2005. Emissions were calculated based on emission factors in the
California Climate Action Registry General Reporting Protocol, Version 3.1 (CCAR 2009).
Residential electricity use was estimated based on average performance for southern California
residences, according to the California Statewide Residential Appliance Saturation Survey (CEC
2004). The energy use figures in this report represent current state-wide average uses, including
those that are compliant with 2005 Title 24 standards. The California Statewide Residential
Appliance Saturation Survey provided estimated energy use of 7,605 kWh annually within California.
In the California Statewide Residential Applicant Saturation Survey, natural gas usage rate were
reported at 421 therms per year.
Water – Water use and energy use are often closely linked. The provision of potable water to
commercial users consumes large amounts of energy associated with five stages: source and
conveyance, treatment, distribution, end use, and wastewater treatment. This inventory estimated
that delivered water for the proposed Project will have an embodied energy of 0.0127 kWh/gallon.
Water usage was estimated based on the CalEEMod model annual estimates of 22,543,300 gallons
of indoor water use and 14,212,100 gallons of outdoor water use for the residences. The model
estimates 38,390,490 gallons of indoor water use and 23,529,655 gallons of outdoor water use for
Heart of the City Specific Plan Amendment (Rancho Coronado) 58 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
the business park, and 1,777,741 gallons of indoor water use and 1,089,583 gallons of outdoor
water use for the retail uses. The embodied energy demand associated with this water use was
converted to GHG emissions with the same emission factors used in the CCAP as for purchased
electricity.
Transportation – Several regulatory initiatives have been passed to reduce emissions from on-road
vehicles, as discussed in Section 1.3. For the purpose of calculating “business as usual” emissions
associated with vehicles, no credit was taken for implementation of the CAFE standards, Pavley
standards, or the LCFS.
Vehicle emissions were calculated based on the average daily trips (ADT) for the project from the
Traffic Impact Analysis (RBF Consulting 2014). The analysis estimated the total number of trips for
the project to be 8,926. It was assumed that the average trip length would be 5.8 miles, based on
the SANDAG average trip length (SANDAG 2012).
GHG emissions under “business as usual” conditions are summarized in Table 9A. As shown in
Table 9A, total CO2e emissions would be 14,767 metric tons per year.
Table 9A. Summary of Estimated Operational GHG Emission – Business as Usual Scenario
Emission Source
Annual Emissions
(Metric tons/year)
CO2 CH4 N2O
Operational Emissions
Electricity Use Emissions 4,199 0.1751 0.0470
Natural Gas Use Emissions 900 0.1000 0.0017
Water Consumption Emissions 1,317 0.0549 0.0147
Vehicle Emissions 7,978 0.0579 0.3345
Amortized Construction Emissions 241 - -
Total 14,635 0.39 0.40
Global Warming Potential Factor 1 21 310
CO2 Equivalent Emissions 14,635 8 124
Total CO2 Equivalent Emissions 14,767
A significance threshold of 28.35% from “business as usual” levels is considered to demonstrate that
a project would be consistent with the goals of AB 32. If the proposed project can demonstrate that
it would meet these goals, its greenhouse gas emissions, emitted either directly or indirectly, would
not have a significant impact on the environment.
Not all of the GHG-reducing project design features identified above are quantifiable due to
scientific and methodological limitations regarding GHG savings. The CEC (Architectural Energy
Corporation 2007) estimates that implementation of the Title 24 standards as of 2008 will result in
reductions in electricity use of 22.7% for residential dwellings. The CEC also estimates that
implementation of the Title 24 standards as of 2008 will result in reductions in natural gas use of
7.4% for residential dwellings.
Heart of the City Specific Plan Amendment (Rancho Coronado) 59 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
GHG emissions from water use would also be reduced through the use of on-site groundwater to
irrigate the park uses. Because the water used for the park uses would be groundwater, there
would be no energy use in the conveyance, treatment, and wastewater disposal from park uses.
The embodied energy for local water sources is estimated at 110 kWh/million gallon (Cooley and
Wilkinson 2012). It is anticipated that water conservation measures that will be implemented for
the development would reduce water consumption by 10 percent. These measures include the use
of low-flow fixtures, use of drought-resistance landscaping, and means to reduce water usage such
as irrigation systems that conserve water.
Implementation of the RPS will affect indirect GHG emissions associated with electricity use for the
project because electricity will be purchased from San Diego Gas and Electric. According to the
SDCGHGI, implementation of the 33 percent RPS mandate, as established by Senate Bill 107, would
reduce GHG emissions by 27 percent from 2005 levels; credit was taken for these GHG savings in
this analysis.
Implementation of the new Federal CAFE standards will achieve reductions that are equivalent to
those proposed in AB 1493, the Pavley bill. Emissions were calculated based on the 2020 emission
factors from the EMFAC2011 model (ARB 2011), with credit for the Pavley standards and the Low
Carbon Fuel Standard.
The results of the GHG inventory for emissions with implementation of GHG reduction measures are
presented in Table 9B.
Table 9B. Summary of Estimated Operational GHG Emission –
With GHG Reduction Measures Scenario
Emission Source
Annual Emissions
(Metric tons/year)
CO2 CH4 N2O
Operational Emissions
Electricity Use Emissions 2,267 0.0946 0.0254
Natural Gas Use Emissions 703 0.0782 0.0013
Water Consumption Emissions 584 0.0244 0.0065
Vehicle Emissions 5,826 0.0405 0.2676
Amortized Construction Emissions 241 - -
Total 9,621 0.24 0.30
Global Warming Potential Factor 1 21 310
CO2 Equivalent Emissions 9,621 5 93
TOTAL CO2 Equivalent Emissions 9,719
Business as Usual CO2 Equivalent Emissions 14,766
Percent Reduction from Business as Usual 34.19%
As shown in Table 9B, with implementation of the project design features, project emissions would
total 9,719 metric tons per year. This represents a 34.19 percent reduction in emissions over
“business as usual” levels. Thus, the project will have a less than significant impact with regard to
Heart of the City Specific Plan Amendment (Rancho Coronado) 60 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
greenhouse gas emissions.
b) Conflict with any applicable plan, policy or regulation of an agency adopted for the purpose of
reducing the emissions of greenhouse gases? Less Than Significant Impact
As part of the General Plan, the City has adopted a Conservation and Open Space Element, which
includes a goal (Goal COS-4) to improve air quality and reduce GHG emissions within the City. As
part of the Conservation and Open Space Element, the City has adopted the following General Plan
Policies designed to achieve the goal of reducing GHG emissions:
• Policy COS-4.3: Participate in regional efforts to reduce greenhouse gas emissions.
• Policy COS-4.4: Quantify community-wide and municipal greenhouse gas (GHG) emissions,
set a reduction goal, identify and implement measures to reduce greenhouse gas emissions
as required by governing legislation.
• Policy COS-4.5: Encourage energy conservation and the use of alternative energy sources
within the community.
• Policy COS-4.6: Promote efficient use of energy and conservation of available resources in
the design, construction, maintenance and operation of public and private facilities,
infrastructure and equipment.
• Policy COS-4.7: As City facilities and services are constructed or upgraded, incorporate
energy and resource conservation standards and practices by:
o Taking a leadership role in implementing programs for energy and water
conservation, waste reduction, recycling and reuse and increased reliance on
renewable energy.
o Upgrading City buildings and infrastructure facilities to comply with State of
California green building standards.
o Implementing landscaping that reduces demands on potable water; this may include
the use of drought tolerant landscaping and/or use of well water for irrigation,
favoring recycling and energy-efficient products and practices when issuing City
purchase agreements.
• Policy COS-4.8: Encourage and support the generation, transmission and use of renewable
energy.
• Policy COS-4.9: Encourage use and retrofitting of existing buildings under Title 24 of the
California Building Energy Code.
As shown in Table 9B, with implementation of the project design features, project emissions would
total 9,719 metric tons per year. This represents a 34.19 percent reduction in emissions over
“business as usual” levels. Thus, the project will have a less than significant impact with regard to
greenhouse gas emissions and would not conflict with any applicable plan, policy or regulation of an
agency adopted for the purpose of reducing the emissions of greenhouse gases.
Heart of the City Specific Plan Amendment (Rancho Coronado) 61 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
VIII. HAZARDS AND HAZARDOUS MATERIALS
A Phase I Environmental Site Assessment was prepared for the project (SCS Engineers, 2012) and is
included as Appendix G of this document. Additionally, a soil characterization report was prepared for
the project site by Geosyntec (2013) and is included as Appendix H of this document.
a) Create a significant hazard to the public or the environment through the routine transport,
use or disposal of hazardous materials? Less Than Significant Impact
Hazardous materials include solids, liquids, or gaseous materials that, because of their quantity,
concentration, or physical, chemical, or infectious characteristics, could pose a threat to human
health or the environment. Hazards include the risks associated with potential explosions, fires, or
release of hazardous substances in the event of an accident or natural disaster, which may cause or
contribute to an increase in mortality or serious illness, or pose substantial harm to human health or
the environment.
The proposed project would involve the transport of fuels, lubricants, and various other liquids
needed for operation of construction equipment at the site and would be transported to the
construction site on an as-needed basis by equipment service trucks. In addition, workers would
commute to the project site via private vehicles, and would operate construction
vehicles/equipment on both public and private streets. Materials hazardous to humans, wildlife, and
sensitive environments would be present during project construction of the pipeline installation.
These materials include diesel fuel, gasoline, equipment fluids, concrete, cleaning solutions and
solvents, lubricant oils, adhesives, human waste, and chemical toilets. The potential exists for direct
impacts to human health and biological resources from accidental spills of small amounts of
hazardous materials from construction equipment during construction of the pipeline; however, the
proposed project would be required to comply with Federal, State, and City Municipal Code
regulations which regulate and control those materials handled onsite. Compliance with these
restrictions and laws ensure that potentially significant impacts would not occur. Therefore, a less
than significant impact is identified.
b) Create a significant hazard to the public or the environment through reasonable foreseeable
upset and accident conditions involving the release of hazardous materials into the
environment? Less Than Significant Impact with Mitigation Incorporated
Phase 1 Environmental Site Assessment Results
A Phase 1 Environmental Site Assessment was prepared by SCS Engineers (2012). The assessment
concluded that there is a low likelihood that a recognized environmental condition exists at the site
as a result of the current or historical site land use or from known and reported off-site sources.
Soil Characterization Analysis Results
Portions of the project site were historically was used for aggregate mining and related activities.
Previous soil characterization activities conducted on the Hanson Property identified arsenic in soil
samples collected within a portion of the project site at concentrations above established
background levels, but the anomalous arsenic concentrations did not appear to be attributable to
historical operations on the Property or other anthropogenic activities. This area of the project site
Heart of the City Specific Plan Amendment (Rancho Coronado) 62 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
is associated with the portion identified for future non-residential mixed-use development in the
southeastern portion of the project site.
In May 2012, Tetra Tech conducted an investigation of soil conditions within the area proposed for
future non-residential mixed-use development. Tetra Tech collected twenty-five soil samples from
seven boring locations (B1 through B7 to evaluate metals concentrations in areas where
“undocumented fill1” had been identified during a prior Phase I ESA and geotechnical investigation.
This undocumented fill is related to grading activities performed during the construction of the Twin
Oaks Valley Road just to the east of the site, and overburden material from onsite mining activities.
Soil sampling was performed under the direction of Tetra Tech using a direct-push rig. Fill soil was
reportedly encountered by Tetra Tech to depths up to approximately 18 feet below ground surface.
Each of the 25 soil samples was analyzed for total metals by EPA Method 6010B/7471A. Arsenic
concentrations in the soil samples ranged from 0.831 mg/kg to 72.2 mg/kg. The remaining metals
concentrations were within the typical range of background concentrations in San Diego soil. Tetra
Tech concluded that arsenic concentrations in soil samples collected at the site are “naturally-
occurring and within the ambient range…and that the arsenic is not an anomalous detection and
does not require further investigation.”
In August 2012, Geosyntec performed additional soil sampling which confirmed arsenic
concentrations in excess of the upper bound California background established by the Department
of Toxic Substances Control (12 mg/kg; DTSC, 2008) in soil localized to the vicinity of Tetra Tech
borings B-1, B-4, and B-5, and adequately delineated the extent of arsenic in soil in the vicinity of
those three borings.
In March 2013 Geosyntec prepared a report titled “Native Background Arsenic Summary” which
outlined the occurrence of naturally-occurring arsenic in San Diego County. The Santiago Peak
Volcanics Formation has historically been economically mined for arsenic in its mineral form as
arsenopyrite. Arsenopyrite, the sulfarsenide of iron, is a principal ore of arsenic. Arsenopyrite is
associated with high temperature hydrothermal veins, in pegmatities, and in areas of contact
metamorphism. Because the formation is volcanic in nature and that hydrothermal alteration in
veins and areas of contact metamorphisim have been identified throughout the formation,
arsenopyrite is associated with the formation and at one time an economically viable mineral
resource in San Diego County. From researching historical arsenic mining operations in San Diego
County located in the Santiago Peak Volcanics Formation, the mines were typically situated in
canyons or the saddles of ridges which are areas where preferential erosion is occurring and
exposing potentially significant arsenopyrite deposits. Veins, contact metamorphosed, and
hydrothermally altered rock tend to be more fractured or have mineralized zones that lead to areas
that are more susceptible to erosional forces. Two documented arsenic mines in San Diego County
that are located within the Santiago Peak Volcanic Formation are the Black Mountain Mine and
Cedar Creek Mine. The Property is underlain by the Santiago Peak Volcanics Formation, and there
are no known anthropogenic sources of arsenic on or near the project site.
Concentrations of arsenic from the samples collected in 2012 by Geosyntec ranged from 3.86 mg/kg
to 159 mg/kg. Geosyntec also collected ten soil samples a hand auger throughout the Hanson
property at depths of 0.5 to 3.0 ft. below ground surface to evaluate background concentrations of
arsenic in soil. The concentrations of arsenic in soil in the 10 background samples ranged from
Heart of the City Specific Plan Amendment (Rancho Coronado) 63 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
4.78 mg/kg to 134 mg/kg. Data from the May and August 2012 soil investigations indicate that
arsenic concentrations are generally higher in the eastern portion of the analysis where the Santiago
Peak Volcanic formation is exposed at or near the existing ground surface, and in fill material in the
north-central portion of the analysis area that was derived from Santiago Peak Volcanics during
grading activities in the eastern portion of the area proposed for future non-residential mixed use
when Twin Oaks Valley Road was constructed in the period between 2004 and 2007.
Results from the previous investigation performed by Tetra Tech and recent investigation performed
by Geosyntec indicate that the majority of the soil samples which contained elevated concentrations
of naturally-occurring arsenic are localized in the area propose for future non-residential mixed use.
Statistical evaluations performed on the data demonstrated that the localized areas of naturally-
occurring elevated arsenic in soil can be effectively managed through soil management activities to
achieve a site that would be suitable for the proposed development.
The requirement for a soils management plan is included as mitigation measure MM-HAZ-1 and
implementation of this measure will be required as a condition of project approval.
MM-HAZ-1 Prior to grading activities, the project applicant shall prepare and implement a soils
management plan that addresses handling of soils containing naturally-occurring
arsenic during grading. The management plan shall be submitted to the City
Engineer for review and approval prior to the issuance of a grading permit.
c) Emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or
waste within one-quarter mile of an existing or proposed school? No Impact
There are no existing or proposed schools within 0.25 mile of the project site. Further, the project
does not propose uses that would emit hazardous emissions or handle hazardous or acutely
hazardous materials or substances. Therefore no impact is identified for this issue area.
d) Be located on a site which is included on a list of hazardous materials sites compiled pursuant
to Government code Section 65962.5 and, as a result, would it create a significant hazard to
the public or the environment? No Impact
The project site is not identified on a list of hazardous materials sites compiled pursuant to
government code Section 65962.5. Therefore no impact is identified for this issue area.
The California Department of Toxic Substances Control maintains an online database (EnvirStor) that
allows for search of permitted facilities and environmental cleanup activities at a specific location. A
review of EnviroStor revealed two entries associated with the project site. The first was associated
with the soil boring for background arscenic testing. The second listing was associated with a
previous project proposal on the site that included a school. Since the school is no longer proposed,
that listing is no longer active. The results of the arscenic testing were addressed in Section VIII(b),
above. No other listings were identified within a quarter-mile of the project site and no impact is
identified for this issue area.
Heart of the City Specific Plan Amendment (Rancho Coronado) 64 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
e) For a project located within an airport land use plan or, where such a plan has not been
adopted, within two miles or a public airport or public use airport, would the project result in
a safety hazard for people residing or working in the project area? No Impact
The proposed project is not located within an airport land use plan area, nor is it within two
miles of a public airport or public use airport. The nearest is the McClellan-Palomar Airport in
Carlsbad, which is located approximately six miles west of the project area. The project site is
located outside the over-flight notification area, but is located within the Review Area 2 of the
airport influence area. The influence area is regulated by the Airport Land Use Commission
(ALUC), which regulates land uses in the area to be compatibility with airport-related noise,
safety, airspace protection, and over-flight factors. Review Area 2 consists of limits on heights
of structures in areas of high terrain. The project site would not be characterized as high terrain,
as it is situated south and east of higher terrain areas. Therefore, no impact is identified for this
issue area.
f) For a project within the vicinity of a private airstrip, would the project result in a safety hazard
for people residing or working in the project area? No Impact
The proposed project is not located within the vicinity of a private airstrip. Therefore the project
does not have the potential to result in a safety hazard for people residing or working in the project
area. No impact is identified for this issue area.
g) Impair implementation of or physically interfere with an adopted emergency response plan or
emergency evacuation plan? Less than Significant Impact
The project does not propose any development that would impair implementation of or physically
interfere with an adopted emergency response plan or evacuation plan. Construction of the project
would not result in any complete road closures. The San Marcos Fire Department has reviewed the
project and has not raised any concerns on this issue. Therefore, impacts are less than significant.
h) Expose people or structures to a significant risk of loss, injury or death involving wildland fires,
including where wildlands are adjacent to urbanized areas or where residences are intermixed
with wildlands? Less Than Significant Impact with Mitigation Incorporated
The project proposes development adjacent to natural areas which will be preserved as open space.
This creates and areas where development will be adjacent to wildland areas that have a high fire
risk. This represents a significant impact (Impact HAZ-2). Implementation of mitigation measures
MM-HAZ-2, which requires preparation and implementation of a Fire Protection Plan will reduce
this impact to below a level of significance.
MM-HAZ-2 Prior to issuance of building permits, a fire protection plan shall be prepared for the
project and submitted to the Planning Director and Fire Marshal for review and
approval. The fire protection plan shall include fire fuel clearing and fire fuel
management zones to provide a minimum 150-foot buffer between proposed
structures and natural habitat. The fire protection plan shall identify the responsible
parties for the ongoing fire fuel maintenance and the mechanism to ensure
compliance with fire clearing requirements. Implementation of the fire protection
plan shall be required prior project occupancy.
Heart of the City Specific Plan Amendment (Rancho Coronado) 65 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Thus implementation of mitigation measures MM-HAZ-2 will reduce the potential impact of
exposing people or structures to a significant loss, injury, or death involving wildland fires, would be
reduced to below a level of significance.
IX. HYDROLOGY AND WATER QUALITY
a) Violate any water quality standards or waste discharge requirements? Less than Significant
Impact
The project will comply with all water quality standards and waste discharge requirements. Since
the project includes disturbance to more than an acre, a Construction General Permit from SWRCB
will be require prior to the issuance of a grading permit. A Storm Water Pollution Prevention Plan
(SWPPP) will be developed and implemented in accordance with the appropriate Risk Level, as
determined by the City Engineer. The SWPPP will identify Best Management Practices (BMPs) to
protect storm water runoff.
New Regional MS4 Permit
On May 8, 2013, the SDRWQCB adopted Order R9 2013-0001, the new Regional MS4 Permit. The
permit became effective June 27, 2013. The City is required to update its SUSMP land development
requirements within three months of the SDRWQCB concurrence of the Carlsbad Watershed WQIP
which is estimated to be 24 months after the May 8, 2013 adoption of R9 2013-0001 or
approximately December 2015. The City will make project-specific determinations on a case-by-case
basis as to what constitutes prior lawful approval based on its Municipal Code, Ordinances, and
project milestones within the development process to identify the appropriate MS4 permit land
development requirements that are applicable to each project.
The proposed project has been designed to comply with the land development requirements of
Order R9 2007-001 and the City SUSMP (as amended January 14, 2011). Long term water quality and
HMP requirements are mitigated through appropriate design and mitigation requirements for
residential, parking lot, and street land uses.
The proposed project is on a development schedule to achieve prior lawful approval under the land
development requirements of R9 2007-0001 in accordance with the City’s municipal ordinances and
is therefore in compliance with the SDRWQCB MS4 permit at this time.
Prior to final issuance of construction permits, the City will evaluate the project’s land development
milestones and construction schedule and issue a Final Determination of Prior Lawful Approval and
determination of applicable MS4 Permit development requirements and MS4. The project will be
required to provide a design to mitigate water quality and HMP under the land development
requirements deemed to be in effect of either R9 2007-001 or R9 2013-0001.
At this time it is anticipated that no substantive changes will occur with project design based on the
recent adoption of R9 2013-0001and the projects development milestone schedule for construction
and implementation.
In summary, the proposed project will not violate any water quality standards or waste discharge
requirements. Impact will be less than significant.
Heart of the City Specific Plan Amendment (Rancho Coronado) 66 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
b) Have a potentially significant adverse impact on groundwater quality or cause or contribute to
an exceedance of applicable groundwater receiving water quality objectives or degradation of
beneficial uses? No Impact
The project does not propose any uses or irrigation with groundwater or wells that would impact
ground water quality or cause or contribute to an exceedance of applicable groundwater receiving
water quality objectives or degradation of beneficial uses. The project proposes residential, mixed-
use non residential, active park, and habitat conservation. Therefore no impact is identified.
c) Substantially deplete groundwater supplies or interfere substantially with groundwater
recharge such that there would be a net deficit in aquifer volume or a lowering of the local
groundwater table level (e.g., the production rate of preexisting nearby wells would drop to a
level which would not support existing land uses or planned uses for which permits have been
granted)? No Impact
The proposed project will not use groundwater, thus the project would not result in the substantial
depletion of groundwater supplies or interfere substantially with groundwater recharge. Thus no
impact is identified for this issue area.
d) Substantially alter the existing drainage pattern of the site or area, including through the
alteration of the course of a stream or river, in a manner which would result in substantial
erosion or siltation on-or off-site (e.g. downstream)? Less than Significant Impact
This threshold is analyzed in terms of short term project construction impact and long term/project
operation impacts.
Short Term (Project Construction)
The project site is topographically diverse and has hill and valley areas. Existing elevations range
from a high of approximately 875 feet msl in the southeastern portion of the site to a low of
approximately 720 feet msl in the northern portion of the project site.
Grading would occur on the project site to prepare the site roadways, utility infrastructure,
residential pads, and future pads for the park and non-residential mixed use area. The project will
incorporate construction BMPs in compliance with the General Construction Permit. These BMPs
focus on areas such as good site management/housekeeping, non-stormwater management,
erosion control, sediment control, run-on and run-off control, inspection/maintenance/repair, rain
event action plan, and monitoring/reporting requirements. Implementation of these BMPs will
further reduce the potential for erosion and siltation entering waterways. Impact will be less than
significant.
Long Term (Project Operation)
The project will increase the area of impervious surface on the project site. However, based upon
the analysis prepared by Fuscoe Engineering (2013), runoff amounts and quantities would be similar
in the pre- and post-condition.
Heart of the City Specific Plan Amendment (Rancho Coronado) 67 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
To provide water quality treatment and hydromodification mitigation of runoff from the project site
and tributary areas, the project was divided into drainage management areas (DMA), and one best
management practice (BMP) has been provided in each DMA to provide water quality treatment
and hydromodification mitigation. The BMPs used for the project are bioretention basins. The
following table shows the pre-development runoff in cubic feet per second (cfs) as well as the post-
development condition with and without the proposed low impacts development (LID) features.
Basin and Flow Condition
Peak Runoff (CFS) by Recurrence Interval
0.5Q2 Q2 Q5 Q10
BMP-3 Pre-Development .89 1.78 2.69 3.56
Post-Development
(Unmitigated) 1.31 2.63 3.43 4.71
Post-Development
(Mitigated) 0.44 0.87 1.42 1.79
BMP-5 Pre-Development 1.51 3.03 4.43 5.97
Post-Development
(Unmitigated) 2.40 4.79 6.27 8.60
Post-Development
(Mitigated) 1.33 2.66 3.61 4.61
BMP-7 Pre-Development 2.29 4.57 6.75 8.70
Post-Development
(Unmitigated) 3.14 6.27 8.14 11.15
Post-Development
(Mitigated) 1.41 2.83 4.19 4.89
Source: Fuscoe Engineering (2013)
As shown in the table, the post-development (mitigated) condition has runoff values that are below
the pre-development conditions. The project incorporates LID features and BMPs which minimize
the potential for erosion and siltation. The project conserves natural areas, soils and vegetation. The
project detains and retains runoff through the site through the use of bioretention features.
Bioretention will be used to achieve compliance with stormwater treatment requirements as well as
the LID requirements in the stormwater NPDES permit. Bio-retention was selected the LID to treat
the stormwater runoff project the project site. Impacts would be less than significant.
e) Create a significant adverse environmental impact to drainage patterns due to changes in
runoff flow rates or volumes? Less than Significant Impact
The project will increase the area of impervious surface on the project site due to the construction
of roads and structures. The WQIP assumed that for those areas proposed for development,
approximately 70 percent of the area would be impervious. The project will retain over 129 as
preserved open space.
Impervious surfaces can increase runoff flow rates and volumes; however the project has been
designed to maintain pre-condition runoff amounts and quantities on the project site, as discussed
in threshold IX.d, above. Runoff rates and volumes in the post-development condition will be less
than the pre-development condition when BMPs and LID requirements are considered. Thus the
project would not result in a significant adverse environmental impact to drainage patterns due to
change in runoff rates or volumes and impacts are less than significant.
Heart of the City Specific Plan Amendment (Rancho Coronado) 68 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
f) Substantially alter the existing drainage pattern of the site or area, including through the
alteration of the course of a stream or river, or substantially increase the rate or amount of
surface runoff in a manner, which would result in flooding on-or off-site? Less than Significant
Impact
The project is still adequately designed such that the project would not substantially alter the
existing drainage pattern of the site or area, including through the alteration of the course of a
stream or river, or substantially increase the rate or amount of surface runoff in a manner which
would result in flooding on or off site.
Runoff rates and volumes in the post-development condition will be less than the pre-development
condition when BMPs and LID requirements are considered. Thus the project would not result in a
significant adverse environmental impact to drainage patterns due to change in runoff rates or
volumes and impacts are less than significant.
There are no streams or rivers on the project site, though there are wetland/riparian areas that have
been created through runoff. These areas will be enhanced and restored as part of the proposed
project’s mitigation for impacts to biological resources.
g) Create or contribute runoff water which would exceed the capacity of existing or planned
storm water drainage systems or provide substantial additional sources of polluted runoff?
Less than Significant Impact
The project proposes a comprehensive stormwater management plan that includes stormwater
improvements within the project boundary. This includes bio-retention ponds that will detain and
retain stormwater flows from the pads and roadways. Construction of these facilities is proposed
within the development footprint for the project. An expansion of existing facilities will not be
required to serve the project. Thus impacts would be less than significant.
h) Result in increased impervious surfaces and associated increased runoff? Less than Significant
Impact
The project will increase the area of impervious surface on the project site due to the construction
of roads and structures. The WQIP assumed that for those areas proposed for development,
approximately 70 percent of the area would be impervious. The project will retain over 129 as
preserved open space.
Impervious surfaces can increase runoff flow rates and volumes; however the project has been
designed to maintain pre-condition runoff amounts and quantities on the project site, as discussed
in threshold IX.d, above. Runoff rates and volumes in the post-development condition will be less
than the pre-development condition when BMPs and LID requirements are considered. Thus the
project would not result in a significant adverse environmental impact related to an increase in
impervious surfaces and impacts are less than significant.
Heart of the City Specific Plan Amendment (Rancho Coronado) 69 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
i) Result in significant alteration of receiving water quality during or following construction? Less
than Significant Impact
The analysis of this threshold considers both short term and long term water quality. Potential
construction-related impacts associated with receiving water quality would include siltation and
erosion, the use of fuels for construction equipment, and the generation of trash and debris from
the construction site. Project design feature have been identified that will minimize these potential
for construction-related water quality impacts.
Short Term
The project will incorporate construction-related water quality BMPs to protect water quality. Such
measures could include, but are not limited to:
• Use of sediment trapping devices to control sediment runoff;
• Proper containment and disposal of trash/debris;
• Use of erosion control devices to minimize runoff during rain events; and
• Additional measures to be identified once SWPPP is available prior to the issuance of the
grading permit and start of work onsite
These measures are designed to minimize the generation of pollutants, including sediment,
trash/debris, and erosion. Preparation and implementation of a SWPPP and construction-related
water quality BMPs will ensure that there are no significant alterations to receiving water quality
during construction. Impacts would be less than significant.
Long Term (Project Operation)
With regard to project operation, the project includes a comprehensive water quality management
approach. The complete WQIP is included as Appendix I. The project proposes the comprehensive
use of bio retention and filtration Additionally, the project will implement a variety of site design,
source control, LID, and treatment control BMPs in accordance with Order R9 2007-001 to treat to a
medium pollutant removal rate or better for the pollutants of concern (nutrients and bacteria) and
minimize the potential for pollutants such as sediment, trash, metals, bacteria, oil/grease and
organics prior to reaching the storm drain and off-site waterways. The project is required to
integrate into its design site design, source control, LID, and treatment control BMPs in accordance
to R9 2007-0001 or R9 2013-0001. Thus the project will would not result in significant alterations to
receiving water quality after construction and impacts are less than significant.
j) Result in an increase in pollutant discharges to receiving waters? Consider water quality
parameters such as temperature, dissolved oxygen, turbidity and other typical storm water
pollutants (e.g. heavy metals, pathogens, petroleum derivatives, synthetic organics, sediment,
nutrients, oxygen-demanding substances, and trash). Less than Significant Impact
The project site is located in the Richland (904.52) hydrologic sub-area of the San Marcos (904.5)
hydrologic area of the Carlsbad watershed. Impaired waterbodies in this watershed include San
Marcos Creek (DDE, phosphorus, sediment toxicity and selenium), Lake San Marcos (ammonia as
nitrogen and nutrients) Batiquitos Lagoon (total coliform) and the Pacific Ocean (total coliform).
Heart of the City Specific Plan Amendment (Rancho Coronado) 70 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Anticipated pollutants to be generated by the project include sediment, nutrients, heavy metals,
organic compounds, trash/debris, oil/grease and bacteria/viruses. Potential pollutants that could
also include oxygen/demanding substances.
The project includes a comprehensive water quality management approach to ensure that there will
not be an increase in pollutant discharge to receiving waters. The comprehensive use of bio
filtration, including bioretention ponds as well as self-treating areas to effectively treat stormwater
runoff prior to discharge from the site and to receiving waters.
Bioretention basins are landscaped depressions or shallow basins used to slow and treat on-site
stormwater runoff. Stormwater is directed to the basin and then percolates through the system
where it is treated by a number of physical, chemical and biological processes. The slowed,
cleaned water is allowed to infiltrate native soils or directed to nearby stormwater drains or
receiving waters. A cross section of a typical bioretention basin is included on Sheet 3 of the WQIP
(Appendix I).
The City’s SUSMP requires that the pollutants of concern for each impaired water body in each
watershed be treated by engineered treatment controls to a medium pollutant removal efficiency or
better prior to leaving each development site. This requirement results in reductions in pollutants.
Bioretention has a high efficiency for removal of sediments, nutrients, trash, metals, oil/grease,
organics and oxygen demanding substances and has a medium efficiency for removal of bacteria.
The bioretention features will be subject to regular inspection and maintenance. The maintenance
requirements are detailed on the last sheet of the WQIP (Appendix I). The property owner is
required, pursuant to the City’s Municipal Code Section 4.15 and the City’s current local SUSMP, to
enter into a stormwater management and discharge control maintenance agreement for the
installation and maintenance of permanent best management practices prior to issuance of permits.
Since the project includes a comprehensive approach to the handling and treatment of stormwater
runoff and will achieve a high efficiency for removal of sediments, nutrients, trash, metals,
oil/grease, organics and oxygen demanding substances and has a medium efficiency for removal of
bacteria, impact to receiving waters would be less than significant.
k) Be tributary to an already impaired water body as listed on the Clean Water Act Section
303(d) list. If so, can it result in an increase in any pollutant for which the water body is
already impaired? Less than Significant Impact
The project site is located in the Richland (904.52) hydrologic sub-area of the San Marcos (904.5)
hydrologic area of the Carlsbad watershed. Impaired waterbodies in this watershed include San
Marcos Creek (DDE, phosphorus, sediment toxicity and selenium), Lake San Marcos (ammonia as
nitrogen and nutrients) Batiquitos Lagoon (total coliform) and the Pacific Ocean (total coliform).
Anticipated pollutants to be generated by the project include sediment, nutrients, heavy metals,
organic compounds, trash/debris, oil/grease and bacteria/viruses. Potential pollutants that could
also include oxygen/demanding substances.
The project includes a comprehensive water quality management approach to ensure that there will
not be an increase in pollutant discharge to receiving waters. The comprehensive use of bio
Heart of the City Specific Plan Amendment (Rancho Coronado) 71 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
filtration, including bioretention basins as well as self-treating areas to effectively treat stormwater
runoff prior to discharge from the site and to receiving waters.
Bioretention basins are landscaped depressions or shallow basins used to slow and treat on-site
stormwater runoff. Stormwater is directed to the basin and then percolates through the system
where it is treated by a number of physical, chemical and biological processes. The slowed,
cleaned water is allowed to infiltrate native soils or directed to nearby stormwater drains or
receiving waters. A cross section of a typical bioretention basin is included on Sheet 3 of the WQIP
(Appendix I).
The City’s SUSMP requires that the pollutants of concern for each impaired water body in each
watershed be treated by engineered treatment controls to a medium pollutant removal efficiency or
better prior to leaving each development site. This requirement results in reductions in pollutants.
Bioretention has a high efficiency for removal of sediments, nutrients, trash, metals, oil/grease,
organics and oxygen demanding substances and has a medium efficiency for removal of bacteria.
The bioretention features will be subject to regular inspection and maintenance. The maintenance
requirements are detailed on the last sheet of the WQIP (Appendix I). The property owner is
required, pursuant to the City’s Municipal Code Section 4.15 and the City’s current local SUSMP, to
enter into a stormwater management and discharge control maintenance agreement for the
installation and maintenance of permanent best management practices prior to issuance of permits.
Since the project includes a comprehensive approach to the handling and treatment of stormwater
runoff and will achieve a high efficiency for removal of sediments, nutrients, trash, metals,
oil/grease, organics and oxygen demanding substances and has a medium efficiency for removal of
bacteria, impact to impaired water bodies would be less than significant.
l) Be tributary to environmentally sensitive areas (e.g. MSCP, RARE, Areas of Special Biological
Significance, etc.)? If so, can it exacerbate already existing sensitive conditions? Less than
Significant Impact
The project site is located in the Richland (904.52) hydrologic sub-area of the San Marcos (904.5)
hydrologic area of the Carlsbad watershed. Impaired waterbodies in this watershed include San
Marcos Creek (DDE, phosphorus, sediment toxicity and selenium), Lake San Marcos (ammonia as
nitrogen and nutrients) Batiquitos Lagoon (total coliform) and the Pacific Ocean (total coliform).
Anticipated pollutants to be generated by the project include sediment, nutrients, heavy metals,
organic compounds, trash/debris, oil/grease and bacteria/viruses. Potential pollutants that could
also include oxygen/demanding substances.
The project site is located outside of the Biological Resource Conservation area for the MHCP. The
project includes areas that are proposed for wetland restoration, creation and enhancement.
The project includes a comprehensive water quality management approach to ensure that there will
not be an increase in pollutant discharge to receiving waters. The comprehensive use of bio
filtration, including bioretention basins as well as self-treating areas to effectively treat stormwater
runoff prior to discharge from the site. Thus the project would not exacerbate already sensitive
conditions and impacts would be less than significant.
Heart of the City Specific Plan Amendment (Rancho Coronado) 72 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
m) Have a potentially significant environmental impact on surface water quality, to either
marine, fresh or wetland waters? Less than Significant Impact
The project site supports wetlands and jurisdictional waters. The project will directly impact
wetlands and jurisdictional waters as part of the project development; however, impacts will be
mitigated to below a level of significance through a comprehensive habitat restoration, creation and
preservation effort both on and off-site. The project will implement BMPs during project
construction to minimize potential impact to surface water quality. The project also includes a
comprehensive water quality approach including biofiltration, to reduce pollutants that would be
generated during project operation. Incorporation of these measures would ensure that impacts are
less than significant.
n) Otherwise substantially degrade water quality? Less than Significant Impact
As detailed in IX(j), above, the project includes a comprehensive water quality management
approach. The WQIP is included as Appendix I. The comprehensive use of biofiltration, combined
with on- and off-site riparian enhancement which will further improve water quality. See IX(k),
above. Impacts are less than significant.
o) Place housing within a 100-year flood hazard area as mapped on a federal Flood Hazard
Boundary or Flood Insurance Rate Map or other flood hazard delineation map? No Impact
The project does not propose any housing within a 100-year flood hazard area as mapped on a
federal Flood Hazard Boundary, FIRM, or other flood hazard delineation map. No impact is
identified.
p) Place within a 100-year flood hazard area structures which would impede or redirect flood
flows? No Impact
The project does not propose any structures within a 100-year flood hazard area as mapped on a
federal Flood Hazard Boundary, FIRM, or other flood hazard delineation map. No impact is
identified.
q) Expose people or structures to a significant risk of loss, injury or death involving flooding,
including flooding as a result of the failure of a levee or dam? Less than Significant Impact
The project site is located immediately north and adjacent to South Lake, a storage reservoir with a
dam height of over 75 feet and storage capacity of approximately 300 acre-free at the spillway crest
elevation of 825.5 feet. The Vallecitos Water District is the owner/operator of the lake and its dam.
A Breach Study for South Lake and Development of Inundation Map for Downstream Channel was
prepared by Chang Consultants (2007). The complete study is included as Appendix J of this
document. The purpose of the study was to determine the flood discharge and its downstream
variation as a result of dam failure at South Lake reservoir and to develop an inundation map as a
result of dam failure.
Heart of the City Specific Plan Amendment (Rancho Coronado) 73 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
South Lake outlets through a naturally-lined channel aligned through the proposed project site. The
flow continues to Discovery Lake, then along residential areas and a golf course and ultimately
confluences with Dan Marcos Creek near Discovery Street, upstream of Lake San Marcos.
Based upon the inundation mapping prepared for South Lake under a breach condition, all proposed
residences would be located outside of the inundation zone in the event of a breach of the South
Lake Dam. Further, the project will be conditioned to update the inundation study and obtain the
necessary agency approval in order to reflect the project’s current grading concept. Therefore,
impacts would be less than significant.
r) Inundation by seiche, tsunami, or mudflow? No Impact
The proposed project is not located near a coastline, lake, or mountainous area that would be
subject to a seiche, tsunami, or mudflow. No impacts are identified for this issue area.
X. LAND USE AND PLANNING
a) Physically divide an established community? No Impact
The proposed project would not divide an established community. The project site is currently
undeveloped and would be constructed adjacent to existing residential uses to the north and in the
vicinity of existing multi-family residential uses to the east. The proposed project will provide
infrastructure that would connect offsite residential uses with the proposed park and non-
residential mixed use, also proposed as part of this project. Therefore, no impact is identified for
this issue area.
b) Conflict with any applicable land use plan, policy, or regulation of an agency with jurisdiction
over the project (including, but not limited to the general plan, specific plan, local coastal
program, or zoning ordinance) adopted for the purpose of avoiding or mitigating an
environmental effect? Less than Significant Impact
General Plan
The project site is identified as Focus Area 9 in the General Plan and is identified as a mix of LDR
(Low Density Residential), LMDR (Low Medium Density Residential), MU4 (Mixed Use 4 Non
Residential), OS (Open Space) and P (Park). Per the General Plan, development of 346 single-family
residences, 17 acres of Mixed Use 4 (non-residential mixed use), and 75 acres of park/open space.
The proposed project is consistent with intensity of development contemplated in the General Plan
update. Impacts would be less than significant.
Zoning Ordinance
The project site is zoned Heart of the City Specific Plan. The project includes an amendment to the
Heart of the City Specific Plan. The amended Specific Plan is included as Appendix A.2 of this
document. Implementation of the Specific Plan Amendment, which is one of the discretionary
actions for the project, would make the project consistent with the Zoning Ordinance. Impacts
would be less than significant.
Heart of the City Specific Plan Amendment (Rancho Coronado) 74 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
c) Conflict with any applicable habitat conservation plan or natural community conservation
plan? No Impact
The project site is located outside of the Biological Resource Conservation Area for the Multiple
Habitat Conservation Plan. Therefore the project would not conflict with the provisions of an
adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local,
regional, or state habitat conservation plan and no impact is identified.
XI. MINERAL RESOURCES
a) Result in the loss of availability of a known mineral resource that would be a value to the
region and the residents of the state? No Impact
There are no known mineral resources on the site of value to the region or to residents of the state.
Hanson Aggregate operated on the project site in the past, however the operation closed in 2008.
Therefore, the project would not have an impact on any known mineral resource and no impact is
identified for this issue area.
b) Result in the loss of availability of a locally important mineral resource recovery site
delineated on a local general plan, specific plan or other land use plan? No Impact
There are no known mineral resources on the site of value to the region or to residents of the state.
Hanson Aggregate operated on the project site in the past, however the operation closed in 2008.
Therefore, the project would not have an impact on any known mineral resource and no impact is
identified for this issue area.
XII. NOISE
A noise impact analysis was prepared for the project by LdN Consulting (2014). The complete report
is included as Appendix K of this document.
a) Exposure of persons to or generation of noise levels in excess of standards established in the
local general plan or noise ordinance, or applicable standards of other agencies? Less Than
Significant With Mitigation Incorporated
Existing Noise Environment
Noise measurements were taken in four areas of the project site in November 2011. The results of
the noise level measurements are presented in Table 10. The measurements were taken on site to
establish a baseline of the vehicle noise from adjacent Twin Oaks Valley Road and Village Drive. The
measurements were free of obstruction and had a direct line of sight to the roadway. The overall
sound levels were found to be between 44.2 and 70.8 dBA. Construction was occurring to the east
of the project during the measurements. The noise monitoring locations can be seen in Figure 5.
Heart of the City Specific Plan Amendment (Rancho Coronado) 75 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 10. Measured Ambient Noise Levels
Measurement
Identification Description Time
Noise Levels (dBA Leq)
Leq Lmax Lmin L10 L50 L90
ML 1 North of the site 12:35-12:53 p.m. 44.2 58.0 33.5 47.8 40.1 36.9
ML 2 North of the site 12:57-1:19 p.m. 45.2 60.2 37.0 47.2 42.5 39.5
ML 3 North of the site 1:22-1:42 p.m. 67.3 81.6 40.5 72.0 59.9 49.1
ML 4 Eastern portion of site 1:52-1:58 p.m. 70.8 85.4 54.8 75.1 64.6 57.2
Source: Ldn Consulting (2014)
Future Onsite Noise Analysis – Residential
To control transportation related noise sources such as arterial roads, freeways, airports and
railroads, the City has established guidelines for acceptable community noise levels in the Noise
Element of the General Plan. For noise sensitive rural and single family residential uses, schools,
libraries, parks and recreational areas the City Noise Element requires an exterior noise level of less
than 60 dBA CNEL for outdoor usable areas. For multi-family developments the standard is 65 dBA
CNEL and a standard of 70 dBA CNEL is typically applied to commercial uses.
To determine the future noise environment and impact potentials the Sound32 model was utilized.
Table 11 presents the roadway parameters used in the analysis including the peak traffic volumes,
vehicle speeds and the hourly traffic flow distribution (vehicle mix). The vehicle mix provides the
hourly distribution percentages of automobile, medium trucks and heavy trucks for input into the
Sound32 Model. The Buildout conditions include the future traffic volume forecasts provided in the
Project’s Traffic Study (RBF Consulting, 2014).
Table 11. Future Traffic Parameters
Roadway
Average Daily
Traffic (ADT)1
Peak Hour
Volumes1
Modeled
Speeds
(MPH)
Vehicle Mix %2
Auto
Medium
Trucks
Heavy
Trucks
Twin Oaks Valley Road 40,445
4.056 50 96 2 2
North Village Drive 3,528 353 30 96 2 2
Street A 2,312 231 30 96 2 2
Source: Ldn Consulting (2014)
To evaluate the potential noise impacts on the proposed development, outdoor observers were
located throughout the site and placed five feet above the finished pad elevation. The modeled
observer locations for the potential outdoor use areas for both the residential portion of the site
and the mixed-use area are presented in Figure 6. The modeling results are presented in Table 12
for the unmitigated and mitigated scenarios.
Heart of the City Specific Plan Amendment (Rancho Coronado) 76 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Figure 5. Ambient Noise Monitoring Locations
Heart of the City Specific Plan Amendment (Rancho Coronado) 77 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Figure 6. Modeled Receptor Locations
Heart of the City Specific Plan Amendment (Rancho Coronado) 78 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 12. Future Exterior Noise Levels
Receptor
Number
Receptor
Location
(Pad #)
Unmitigated
Noise Level (dBA
CNEL)
Barrier Heights
(Feet)
Mitigated Noise
Level (dBA CNEL)
Second Floor
Noise Level (dBA
CNEL)
1 3 56 0 55 56
2 16 55 0 54 55
3 11 57 0 56 58
4 31 56 0 55 58
5 12 57 0 56 57
6 47 55 0 55 55
7 72 60 0 59 60
8 68 60 0 59 59
9 67 56 0 56 56
10 105 59 0 59 59
11 111 59 0 58 59
12 117 60 0 59 59
13 119 57 0 56 59
14 121 57 0 55 59
15 126 57 0 55 60
16 127 56 0 53 58
17 129 56 0 54 58
18 131 57 0 55 58
19 133 56 0 53 53
20 136 60 0 57 58
21 139 57 0 54 57
22 140 63 6 59 62
23 142 64 6 60 63
24 144 66 8 60 64
25 146 66 10 60 64
26 149 66 10 60 63
27 150 63 5 59 63
28 152 63 5 59 62
29 Mixed-Use 67 -- -- 67
30 Mixed-Use 71 -- -- 70
31 Mixed-Use 71 -- -- 71
32 Mixed-Use 65 -- -- 65
Source: Ldn Consulting (2014)
Notes:
- = Not applicable
n/a = barrier mitigation not required at this location
Heart of the City Specific Plan Amendment (Rancho Coronado) 79 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Based upon the modeling results, noise mitigation will be required along the top of slope for
some residential pads adjacent to Village Drive, Twin Oaks Valley Drive and future internal streets
(Impact N-1). Therefore, mitigation measures MM-N-1 and MM-N-2 will be required as a condition
of project approval. With implementation of these mitigation measures, onsite noise levels will be
consistent with the Noise Element of the City’s General Plan and will be reduced to below a level of
significance.
MM-N-1 Sound barriers ranging from five to ten feet shall be constructed to reduce future
onsite noise levels to be consistent with the Noise Element of the San Marcos
General Plan (60 dBA CNEL for single family and 65 dBA for multifamily). Locations
and heights of the proposed barriers are presented in Figure 7, Noise Mitigation
Measures. Barriers could include berms, wall, glass or a combination of these to
meet the required noise attenuation.
MM-N-2 A final noise assessment shall be prepared prior to the issuance of the first building
permit. This final report would identify the interior noise requirements based upon
architectural and building plans to meet the City’s established interior noise limit of
45 dBA CNEL2.
Future Onsite Noise Analysis – Non-Residential Mixed Use
No outdoor noise sensitive uses are anticipated on the non-residential mixed-use portion of the
project site; therefore no outdoor impacts from the roadways are anticipated. Table 12 provides
the future unshielded noise levels that would occur at the building façades for the mixed use pads.
As shown in Table 12, mixed-use pads could experience sound level is excess of 70 dBA CNEL in an
unmitigated condition. If outdoor use areas are proposed at the mixed use area (e.g., employee
picnic areas) this would result in a significant impact (Impact N-3). Therefore, mitigation measures
N-3 will be required as a condition of project approval. Implementation of mitigation measures MM-
N-3 would reduce the potential impact to below a level of significance.
MM-N-3 If outdoor usable areas are proposed in the non-residential mixed use areas of the
project, the design shall consider shielding form the buildings, increased setbacks
from the roadways or conduct a site specific noise study to determine compliance.
An interior noise assessment is required to mitigate the exterior noise levels to an
interior level of 50 dBA CNEL. This report should be conducted prior to the issuance
of building permits and would finalize the noise requirements based upon actual
building design specifications.
2 Interior noise levels of 45 dBA CNEL can easily be obtained with conventional building construction methods and providing a
closed window condition requiring a means of mechanical ventilation (e.g. air conditioning).
Heart of the City Specific Plan Amendment (Rancho Coronado) 80 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Figure 7. Noise Mitigation Measures – Barrier Height and Locations
b) Exposure of persons to or generation of excessive groundbourne vibrations or groundbourne
noise levels? Less Than Significant Impact
Construction Vibration Analysis
The nearest vibration-sensitive uses are the residences located to the east, 200 feet or more from
the proposed construction. Table 13 lists the average vibration levels that would be experienced at
the nearest vibration sensitive land uses to the east from temporary construction activities. Loaded
trucks will be traveling along the western portion of the site and were assessed at a minimum
distance of 200 feet to be conservative.
Heart of the City Specific Plan Amendment (Rancho Coronado) 81 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 13. Vibration Levels from Construction Activities (Residential Receptors)
Equipment
Approximate
Velocity Level
at 25 Feet
(VdB)
Approximate
RMS Velocity
at 25 Feet
(in/sec)
Approximate
Velocity Level
at 200 Feet
(VdB)
Approximate
RMS Velocity
at 200 Feet
(in/sec)
Small bulldozer 58 0.003 33.9 0.0001
Jackhammer
79 0.035 54.9 0.0015
Loaded trucks 86 0.076 61.9 0.0034
Large bulldozer 87 0.089 62.9 0.0039
FTA Criteria 80 0.2
Significant Impact? No No
Note: 1 PPV at Distance D = PPVref x (25/D)
1.5
The Federal Transit Administration (FTA) has determined vibration levels that would cause
annoyance to a substantial number of people and potential damage to building structures. The FTA
criterion for vibration induced structural damage is 0.20 in/sec for the peak particle velocity (PPV).
Project construction activities would result in PPV levels below the FTA’s criteria for vibration
induced structural damage. Therefore, construction activities would not result in vibration-induced
structural damage to residential buildings near the demolition and construction areas. The FTA
criterion for infrequent vibration induced annoyance is 80 Vibration Velocity (VdB) for residential
uses. Construction activities would generate levels of vibration that would not exceed the FTA
criteria for nuisance for nearby residential uses. Therefore, vibration impacts would be less than
significant.
Blasting Vibration Analysis
The City of San Marcos Title 17 of the City’s Municipal Code states that all blasting operations within
the City of San Marcos are prohibited unless a Certificate of Authorization is first obtained from the
San Marcos Building Director and an Operations Permit issued by the Fire Chief. Additional relevant
sections of the City’s Code for Blasting are provided below:
• The general contractor or property owner/developer shall give reasonable notice in writing
at the time of issuance of a building permit, grading permit or encroachment license to all
residences or businesses within 600 feet of any potential blast location. The notice shall be
in a form approved by the Building Director. Any resident or business receiving such notice
may request of the Building Director that a notice of impending blasting be given by the
blaster at the time of the 12 hour advance notice given to the Building Director. The general
contractor or property owner/developer shall make all reasonable efforts to contact any
and all parties requesting the second notice.
• The blaster shall file a written certification with the Building Director certifying that the
general notice required by Section 17.60.060(b) has been given. The certificate shall include
addresses and date(s) of notification. A copy shall be retained on file at the Building Division.
• Inspections of all structures within 300 feet of the blast site shall be made before blasting
operations. The persons inspecting shall obtain the permission of the building owner to
Heart of the City Specific Plan Amendment (Rancho Coronado) 82 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
conduct an inspection. The inspections shall be done by a registered structural engineer
employed by the blaster or project contractor. The inspection shall be only for the purpose
of determining the existence of any visible or reasonably recognizable pre-existing defects
or damages in any structure. Inspection refusal shall be at the discretion of the property
owner.
• Blasting shall only be permitted between the hours of 9:00 a.m. and 4:00 p.m. during any
weekday, Monday through Friday, exclusive of City recognized holidays unless special
circumstances warrant another time or day and special approval is granted by the Building
Director and Fire Chief.
Blasting for construction projects typically results in an RMS vibration velocity of about 100 VdB at
50 feet from the blast based on FTA findings. This is equivalent to a peak particle velocity of about
0.4 inch per second. As discussed above the smallest distance between an existing residence and
the blasting activity was assumed to be 200 feet. Given attenuation of vibration velocities with
distance, the RMS vibration velocity and peak particle velocity at the nearest existing residence
would be about 82 VdB and 0.05 inch per second, respectively. Based on the construction vibration
damage criteria published by the FTA, the threshold vibration levels for damage to "Non-engineered
timber and masonry buildings" are 94 VdB and 0.20 inch per second. Therefore, the effect of the
blasting activity on nearby residential structures will not be significant. However, it should be noted
that the human annoyance criterion of 80 VdB would be slightly exceeded when blasting occurred
within about 250 feet of existing residences. If blasting is required within 250 feet of existing
residences, the potential annoyance may not be completely avoided but can be minimized by
following the City’s blasting procedures as stated above, and with proper notice annoyances can be
avoided.
c) A substantial permanent increase in ambient noise levels in the project vicinity above levels
existing without the project? Less Than Significant With Mitigation Incorporated
Project Related Offsite Transportation Noise
Because mobile/traffic noise levels are calculated on a logarithmic scale, a doubling of the traffic
noise or acoustical energy results in a noise level increase of 3 dBA. Therefore the doubling of the
traffic volume, without changing the vehicle speeds or mix ratio, results in a noise increase of 3 dBA.
Community noise level changes greater than 3 dBA are often identified as audible and considered
potential significant, while changes less than 1 dBA will not be discernible to local residents. In the
range of 1 to 3 dBA, residents who are very sensitive to noise may perceive a slight change.
Community noise exposures are typically over a long time period rather than the immediate
comparison made in a laboratory situation. Therefore, the level at which changes in community
noise levels become discernible is likely greater than 1 dBA and 3 dBA appears to be appropriate for
most people. For the purposes for this analysis a direct and cumulative roadway noise impacts
would be considered significant if the project increases noise levels for a noise sensitive land use by
3 dBA CNEL and if the project increases noise levels above an unacceptable noise level per the City’s
General Plan in the area adjacent to the roadway segment.
The projected off-site Project related roadway segment noise levels were calculated using the
methods in the Highway Noise Model published by the Federal Highway Administration (FHWA
Heart of the City Specific Plan Amendment (Rancho Coronado) 83 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Highway Traffic Noise Prediction Model, FHWA-RD-77-108, December, 1978).
Project Direct Off-Site Noise Impact Analysis
To determine if direct off-site noise level increases associated with the development of the
proposed project will create noise impacts. The noise levels for the existing conditions were
compared with the noise level increase from the Project. Utilizing traffic assessment prepared for
the project (RBF Consulting 2014) noise contours were developed for the following traffic scenarios:
• Existing: Current day noise conditions without construction of the project.
• Existing Plus Project: Current day noise conditions plus the completion of the project.
• Existing vs. Existing Plus Project: Comparison of the direct project related noise level
increases in the vicinity of the project site.
The noise levels and reference distances to the 60 dBA CNEL contours for the roadways in the
vicinity of the Project site are given in Table 14 for the Existing Scenario and in Table 15 for the
Existing Plus Project Scenario. It should be noted that the values in Tables 14 and 15 do not take
into account the effect of any noise barriers or topography that may affect ambient noise levels.
Table 14. Existing Roadway Noise Levels
Roadway Roadway Segment ADT1
Vehicle
Speeds
(MPH)1
Noise Level
@ 50-Feet
(dBA CNEL)
60 dBA CNEL
Contour
Distance
(Feet)
Twin Oaks Valley Rd.
SR-78 Ramps to Barham Dr. 39,465 50 76.2 2,108
Barham Dr. to Campus Marketplace 28,659 50 74.9 1,531
Campus Marketplace to Craven Rd. 29,990 50 75.1 1,602
Craven Rd. to North Village Dr. 21,750 50 73.7 1,162
North Village Dr. to South Village Dr. 17,491 50 72.7 934
South Village Dr. to School-Park Access 17,056 50 72.6 911
South of School-Park Access 17,056 50 72.6 911
Craven Road
Twin Oaks Valley Rd. to Rush Dr. 10,294 45 69.4 432
Rush Dr. to Echo Lane 15,746 45 71.2 661
Echo Lane to Santa Barbara Drive 16,013 45 71.3 672
Santa Barbara Dr. Craven Rd. to Orchid Avenue 1,181 30 57.0 25
Village Drive North Twin Oaks Valley Road to Carnation Ct. 1,038 30 56.4 22
Source: Ldn Consulting (2014)
Heart of the City Specific Plan Amendment (Rancho Coronado) 84 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 15. Existing + Project Roadway Noise Levels
Roadway Roadway Segment ADT1
Vehicle
Speeds
(MPH)1
Noise Level
@ 50-Feet
(dBA CNEL)
60 dBA CNEL
Contour
Distance
(Feet)
Twin Oaks Valley Rd.
SR-78 Ramps to Barham Dr. 43,136 50 76.6 2,304
Barham Dr. to Campus Marketplace 32,635 50 75.4 1,743
Campus Marketplace to Craven Rd. 34,195 50 75.6 1,826
Craven Rd. to North Village Dr. 26,531 50 74.5 1,417
North Village Dr. to South Village Dr. 21,009 50 73.5 1,122
South Village Dr. to Site Access 19,329 50 73.1 1,032
South of Site Access 18,976 50 73.1 1,013
Craven Road
Twin Oaks Valley Rd. to Rush Dr. 11,090 45 69.7 465
Rush Dr. to Echo Lane 16,725 45 71.5 702
Echo Lane to Santa Barbara Drive 17,445 45 71.7 732
Santa Barbara Dr. Craven Rd. to Orchid Avenue 2,266 30 59.8 48
Village Drive North Twin Oaks Valley Road to Carnation Ct. 3,188 30 61.3 67
Source: Ldn Consulting (2014)
Table 16 presents the comparison of the Existing Year with and without Project related noise levels. As
shown in Table 16, the overall roadway segment noise levels will increase from 0.0 dBA CNEL to 4.9 dBA
CNEL with the development of the proposed project.
Table 16. Existing vs. Existing + Project Roadway Noise Levels
Roadway Roadway Segment
Existing
Noise Level
@ 50-Feet
(dBA CNEL)
Existing Plus
Project
Noise Level
@ 50-Feet
(dBA CNEL)
Project
Related
Noise Level
Increase
(dBA CNEL)
Twin Oaks Valley Rd.
SR-78 Ramps to Barham Dr. 76.2 76.6 0.4
Barham Dr. to Campus Marketplace 74.9 75.4 0.5
Campus Marketplace to Craven Rd. 75.1 75.6 0.5
Craven Rd. to North Village Dr. 73.7 74.5 0.8
North Village Dr. to South Village Dr. 72.7 73.5 0.8
South Village Dr. to Site Access 72.6 73.1 0.5
South of Site Access 72.6 73.1 0.5
Craven Road
Twin Oaks Valley Rd. to Rush Dr. 69.4 69.7 0.3
Rush Dr. to Echo Lane 71.2 71.5 0.3
Echo Lane to Santa Barbara Drive 71.3 71.7 0.4
Santa Barbara Dr. Craven Rd. to Orchid Avenue 57.0 59.8 2.8
Village Drive North Twin Oaks Valley Road to Carnation Ct. 56.4 61.3 4.9
Source: Ldn Consulting (2014)
Heart of the City Specific Plan Amendment (Rancho Coronado) 85 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
The only segment that has an increase of 3dBA CNEL or greater is the segment of Village Drive North
between Twin Oaks Valley Road and Carnation Court. The overall noise level is 61.3 dBA CNEL with no
shielding along this segment. However, the side and rear yards of existing residences along this segment
of roadway have a minimum five-foot wall already in place. Barriers of this height typically provide a
reduction of 3 to 5 decibels, and those residences that are below the grade of Village Drive North will
have further noise reductions due to grade separation. Thus, the existing walls will reduce the noise
level below the 60 dBA CNEL threshold. Therefore, the Project’s direct contribution to off-site roadways
is less than significant.
Cumulative Off-Site Noise Impact Analysis
To determine if cumulative off-site noise level increases associated with the development of the Project
and other planned or permitted projects in the vicinity will create noise impacts. The noise levels for the
near-term Project Buildout and other planned and permitted projects were compared with the existing
conditions. Utilizing the Project’s traffic assessment (RBF Consulting, 2012) noise contours were
developed for the following traffic scenarios:
• Existing: Current day noise conditions without construction of the project.
• Existing Plus Cumulative Projects Plus Project: Current day noise conditions plus the completion
of the project and the completion of other permitted, planned projects or approved ambient
growth factors.
• Existing vs. Existing Plus Cumulative Plus Project: Comparison of the existing noise levels and
the related noise level increases from the combination of the project and all other planned or
permitted projects in the vicinity of the site.
The existing noise levels and reference distances to the 60 dBA CNEL contours for the roadways in the
vicinity of the project site are given in Table 14 above for the Existing Scenario. The near-term
cumulative noise conditions are provided in Table 17. No noise barriers or topography that may affect
noise levels were incorporated in the calculations.
Table 17. Existing + Project + 2030 Cumulative Roadway Noise Levels
Roadway Roadway Segment ADT1
Vehicle
Speeds
(MPH)1
Noise Level
@ 50-Feet
(dBA CNEL)
60 dBA CNEL
Contour
Distance (Feet)
Twin Oaks Valley Rd.
SR-78 Ramps to Barham Dr. 54,561 50 77.7 2,914
Barham Dr. to Campus Marketplace 39,484 50 76.3 2,109
Campus Marketplace to Craven Rd. 40,715 50 76.4 2,175
Craven Rd. to North Village Dr. 36,746 50 75.9 1,963
North Village Dr. to South Village Dr. 30,869 50 75.2 1,649
South Village Dr. to Site Access 29,002 50 74.9 1,549
South of Site Access 28,560 50 74.8 1,525
Craven Road
Twin Oaks Valley Rd. to Rush Dr. 15,185 45 71.1 637
Rush Dr. to Echo Lane 17,306 45 71.6 726
Echo Lane to Santa Barbara Drive 17,428 45 71.6 731
Santa Barbara Dr. Craven Rd. to Orchid Avenue 2,266 30 59.8 48
Village Drive North Twin Oaks Valley Road to Carnation Ct. 3,472 30 61.7 73
Source: Ldn Consulting (2014)
Heart of the City Specific Plan Amendment (Rancho Coronado) 86 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 18 presents the comparison of the Existing Year and the Near-Term Cumulative noise levels. The
overall roadway segment noise levels will increase from 0.3 dBA CNEL to 5.3 dBA CNEL with the
development of the Project.
The only segment that has an increase of 3dBA CNEL or greater is the segment of Village Drive North
between Twin Oaks Valley Road and Carnation Court. The overall noise level is 61.7 dBA CNEL with no
shielding. However, the side and rear yards of existing residences along this segment of roadway have a
minimum five-foot wall already in place. Barriers of this height typically provide a reduction of 3 to 5
decibels, and those residences that are below the grade of Village Drive North will have further noise
reductions due to grade separation. Thus, the existing walls will reduce the noise level below the 60
dBA CNEL threshold. Therefore, the Project’s direct contribution to off-site roadways is less than
significant. Therefore, the Project’s direct contributions to off-site roadways is less than significant.
Table 18. Existing vs. Existing + Project + 2030 Cumulative Roadway Noise Levels
Roadway Roadway Segment
Existing Noise
Level @ 50 Feet
(dBA CNEL)
Existing Plus
Project Noise
Level @ 50 Feet
(dBA CNEL)
Project
Related
Noise Level
Increase
(dBA CNEL)
Twin Oaks Valley Rd.
SR-78 Ramps to Barham Dr. 76.2 77.7 1.5
Barham Dr. to Campus Marketplace 74.9 76.3 1.4
Campus Marketplace to Craven Rd. 75.1 76.4 1.3
Craven Rd. to North Village Dr. 73.7 75.9 2.2
North Village Dr. to South Village Dr. 72.7 75.2 2.5
South Village Dr. to Site Access 72.6 74.9 2.3
South of Site Access 72.6 74.8 2.2
Craven Road
Twin Oaks Valley Rd. to Rush Dr. 69.4 71.1 1.7
Rush Dr. to Echo Lane 71.2 71.6 0.4
Echo Lane to Santa Barbara Drive 71.3 71.6 0.3
Santa Barbara Dr. Craven Rd. to Orchid Avenue 57.0 59.8 2.8
Village Drive North Twin Oaks Valley Road to Carnation Ct. 56.4 61.7 5.3
Source: Ldn Consulting (2014)
In summary, the proposed project does create a direct and cumulative noise increase of more than 3
dBA CNEL on a segment of Village Drive North, however, this increase does not take into
consideration existing barriers and walls, which provide shielding/noise attenuation. The overall
noise level is 61.7 dBA CNEL with no shielding. However, the side and rear yards of existing
residences along this segment of roadway have five-foot barriers already in place. Barriers of this
height typically provide a reduction of 3 to 5 decibels, thus they will reduce the noise level below the
60 dBA CNEL threshold. Therefore, the Project’s direct and cumulative contributions to off-site
roadway noise increases are less than significant to any existing or future noise sensitive land uses.
d) A substantial temporary or periodic increase in ambient noise levels in the project vicinity
above levels existing without the project? Less Than Significant Impact
Construction noise represents a short-term impact on the ambient noise levels. Noise generated by
construction equipment includes haul trucks, water trucks, graders, dozers, loaders and scrapers can
Heart of the City Specific Plan Amendment (Rancho Coronado) 87 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
reach relatively high levels. Grading activities typically represent one of the highest potential
sources for noise impacts. The most effective method of controlling construction noise is through
local control of construction hours and by limiting the hours of construction to normal weekday
working hours.
The City of San Marcos Municipal Code addresses the limits grading, extraction and construction
activities between 7:00 a.m. and 4:30 p.m. Monday through Friday and no grading, extraction or
construction is allowed on the weekends or holidays. The Municipal code does not set noise limits
on construction activities. Commonly, the City has utilized the County of San Diego’s Noise
Ordinance noise limit of 75 dBA for other projects.
The U.S. Environmental Protection Agency (U.S. EPA) has compiled data regarding the noise
generating characteristics of specific types of construction equipment. Noise levels generated by
heavy construction equipment can range from 60 dBA to in excess of 100 dBA when measured at 50
feet. However, these noise levels diminish rapidly with distance from the construction site at a rate
of approximately 6 dBA per doubling of distance. For example, a noise level of 75 dBA measured at
50 feet from the noise source to the receptor would be reduced to 69 dBA at 100 feet from the
source to the receptor, and reduced to 63 dBA at 200 feet from the source.
Using a point-source noise prediction model, calculations of the expected construction noise
impacts were completed. The essential model input data for these performance equations include
the source levels of each type of equipment, relative source to receiver horizontal and vertical
separations, the amount of time the equipment is operating in a given day, also referred to as the
duty-cycle and any transmission loss from topography or barriers.
The equipment needed for the development will consist of up to a tractor/backhoe, a hydraulic
crane, a loader/grader, a side boom, a water truck, a concrete truck, a concrete pump, haul trucks, a
paver, a roller/compactor, a scraper and a drill rig. Based on the EPA noise emissions, empirical data
and the amount of equipment needed, worst case noise levels from the construction equipment for
site preparation would occur during the grading operations. Additionally, the project will utilize a
Terex Pegson XA750 rock crusher. This equipment is utilized separately from the grading equipment
and will be analyzed separately.
Construction Grading Noise Analysis
The grading activities will consist of the preparation of internal roadways, parking and the finished
pads. The grading equipment will be spread out over the Project site from distances near the
occupied property lines to distances of 350 feet or more away. Based upon the site plan the
majority of the grading operations, on average, will occur more than 350 feet from the property
lines. This means that most of the time the average distance from all the equipment to the nearest
property line is over 350 feet. Table 19 presents the anticipated construction noise levels. As can be
seen in Table 19, at an average distance of 350 feet from the construction activities to the nearest
property line would result in a noise attenuation of -16.9 dBA.
Heart of the City Specific Plan Amendment (Rancho Coronado) 88 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 19. Construction Noise Levels
Equipment Type Quantity Used Source @ 50 Feet (dBA)
Cumulative Noise Level @
50 Feet (dBA)
Tractor/Backhoe 1 72 72.0
Dozer D9 Cat 1 74 74.0
Hydraulic Crane 1 78 78.0
Loader/Grader 1 73 73.0
Side Boom 1 72 72.0
Water Trucks 1 70 70.0
Concrete Trucks 1 75 75.0
Concrete Pump 1 82 82.0
Dump Trucks 1 75 75.0
Paver/Blade 1 75 75.0
Roller/Compactor 1 74 74.0
Scraper 1 75 75.0
Drill Rig 1 83 83.0
Haul Trucks 4 75 81.0
Cumulative Level 89.0
Distance to Sensitive Use 350
Noise Reduction due to Distance -16.9
Property Line Noise Level 72.1
Given this, the noise levels will comply with the 75 dBA Leq standard at the property lines. To help
control the noise levels from the haul trucks a speed limit of 15 MPH should be posted along the on-
site haul route and signage limiting the use of engine “jake” brakes. Additionally, all equipment
should be properly fitted with mufflers and all staging and maintenance should be conducted as far
away for the existing residence as possible. These requirements have been identified as design
features for the project. Therefore, impacts are less than significant and no mitigation is required
during construction of the proposed project.
Rock Crusher Analysis
Due to bedrock conditions, rock crushing may be required during project construction. Rock
crushing would occur between the hours of 7:00 AM and 4:00 PM. The rock crushing equipment will
be located in the northwestern corner of the Mixed-Use site near the access road, more than
1,000 feet from the nearest residence. Based on empirical data collected at a material processing
plant in the City of Upland noise levels from a rock crusher ranged between 80-86 dBA at 45 feet
(Ldn 2011). A worst-case noise level of 86 dBA at 45 feet will be utilized for the analysis.
As can be seen in Table 20, in order to achieve the City’s 60 dBA Leq standard, the rock crusher
needs to be 1,000 feet from the nearest residence. The nearest residence to the proposed rock
crusher location is over 1,000 feet. Figure 8 shows the noise contour of the rock crushing
operations. Given this, the noise levels will comply with the City’s 60 dBA Leq standard at the
property lines. However, should there be a change in rock crusher location or rock crusher type,
there is the potential for a significant noise impact (Impact N-4). Thus implementation of mitigation
measure MM-N-4 will be required as a condition of project approval. Implementation of MM-N-4
will reduce the potential impact to below a level of significance.
Heart of the City Specific Plan Amendment (Rancho Coronado) 89 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 20. Rock Crushing Noise Levels
Equipment Type
Quantity
Used
Source @ 50 Feet
(dBA)
Cumulative Noise Level
@ 50 Feet (dBA)
Terex Pegson XA750 Rock Crusher 1 86 86.0
Distance to Sensitive Use 1,000
Noise Reduction due to Distance -26.0
Property Line Noise Level 60.0
Figure 8. Rock Crusher Noise Contour
Heart of the City Specific Plan Amendment (Rancho Coronado) 90 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
MM-N-4 If rock crushing is proposed, upon starting of crushing operations, noise
measurements of the rock crushing facility shall be required to ensure compliance
with the City’s thresholds. If noise levels are found to be above the established
thresholds of 60 dBA at any existing single family residential use, 65 dBA for any
multifamily use or 70 dBA at a commercial use then additional mitigation in the
form of berms or temporary walls will need to be incorporated into the rock crusher
design to reduce the noise levels to below the City’s thresholds.
e) For a project located within an airport land use plan or, where such a plan has not been
adopted, within two miles of a public airport or public use airport, would the project expose
people residing or working in the project area to excessive noise levels? No Impact
The nearest airport is the Palomar Airport in Carlsbad, which is located approximately six miles west
of the project area. At this distance, the airport would not subject future residents or workers in the
project area to excessive noise levels due to airport operations. Therefore, no impact is identified.
f) For a project within the vicinity of a private airstrip, would the project expose people residing
or working in the project area to excessive noise levels? No Impact
The project site is not located within the vicinity of a private airstrip. Therefore, no impact is
identified for this issue area.
XIII. POPULATION AND HOUSING
a) Induce substantial population growth in an area, either directly (for example, by proposing
new homes and businesses) or indirectly (for example, through extension of roads or other
infrastructure)? Less than Significant Impact
The project proposes the construction of 346 residential units, 24.1 acres of non-residential mixed
use, an approximately 38 acre active park, and associated infrastructure. This will result in an
approximately 1,100 new residents. The proposed development is consistent within the existing
General Plan and proposed adjacent to an area that is already developed with residential. Utility
infrastructure will be sized to serve the project. Proposed roadways will connect to existing
roadways and are provided to serve the project and not any future development areas. Therefore,
impacts would be less than significant for this issue area.
b) Displace substantial numbers of existing housing, necessitating the construction of
replacement housing elsewhere? No Impact
There is no existing housing on the project site. The project site coincides with the former Hanson
Aggregate site, as well as undeveloped natural open space. Therefore, the construction would not
result in the displacement of any people, nor would it necessitate the construction of replacement
housing elsewhere. Therefore, no impact is identified for this issue area.
Heart of the City Specific Plan Amendment (Rancho Coronado) 91 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
c) Displace substantial numbers of people, necessitating the construction of replacement
housing elsewhere? No Impact
There is no existing housing or residents on the project site. The project site coincides with the
former Hanson Aggregate site, as well as undeveloped natural open space. Therefore, the
construction would not result in the displacement of any people, nor would it necessitate the
construction of replacement housing elsewhere. Therefore, no impact is identified for this issue
area.
XIV. PUBLIC SERVICES
a) Fire protection? Less Than Significant Impact
The project site would increase demand on fire protection services due to the construction of 346
residential units, 24 acres of non-residential mixed use development and 38 acres of active park. The
City of San Marcos Fire Department was contacted for their input on the project, including
information regarding stations serving the project, current staffing, response times and other items
related to fire protection services. The Fire Department’s response is included in Appendix L.
The project site is closest to Station 1 and Station 4. Fire Station 1 is located at 180 West Mission
and is staffed with one paramedic engine company (3 personnel), one paramedic truck company (3
personnel) and one paramedic ambulance (2 personnel). Fire Station 4 is located at 204 San Elijo
Road and is staffed with one paramedic engine company (3 personnel), paramedic ambulance (2
personnel) and one battalion chief. Average response times to the project site from either Station 1
or 4 are approximately four minutes based upon most current response data.
The San Marcos Fire Department (2013) indicated that current staff levels and equipment at these
stations are adequate to serve the project; however, the Fire Department continues to experience
an increase in emergency and non-emergency response and additional resources will be needed in
the future. The project would be contained within a preexisting Fire Community Facilities District
and impacts are less than significant.
Additionally, the project will implement the following design features, per fire department
requirements:
• Roadways serving the project shall have a minimum improved paved width of 24 feet with
an additional 8 feet to each side for parking. Any deviations from this or any other roadway
features such as cul-de-sacs and gates must meet the design criteria of the San Marcos Fire
Department.
• Any automatic gates are required to have a Knox rapid entry system and emergency vehicle
strobe detector.
• Fire hydrants with an adequate water supply must be installed at locations approved by the
San Marcos Fire Department. Hydrant spacing shall be 300 feet apart.
• Residential structures shall be fire sprinklered per California Building Code 2010 edition and
city ordinance.
Heart of the City Specific Plan Amendment (Rancho Coronado) 92 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
• Homes and mixed use buildings will be required to be designed using state fire marshal
standards for fire resistive construction features using the California Building Code 2013
edition Chapter 7, design to be reviewed by City Building Department.
• A 150-foot wildland fuel modification is required from all sides of all structures.
As discussed in Section VIII(h), the project proposes development adjacent to natural areas which
will be preserved as open space. This creates and areas where development will be adjacent to
wildland areas that have a high fire risk. This represents a significant impact (Impact HAZ-2).
Implementation of mitigation measures MM-HAZ-2, which requires preparation and
implementation of a Fire Protection Plan will reduce this impact to below a level of significance.
b) Police protection? Less Than Significant Impact
The project site would increase demand on police protection services due to the construction of 346
residential units, 24 acres of non-residential mixed use development and 38 acres of active park. The
San Diego County Sheriff’s Department was contacted for their input on the project, including
information regarding stations serving the project, current staffing, response times and other items
related to police protection services. The Sheriff Department’s response is included in Appendix L.
The project site would be served by the San Marcos Station located at 182 Santar Place, which is
located approximately four miles from the project site. Based upon information from Corporal
Malcolm Horst (2013), current staffing levels are adequate to meet current demand. The addition of
development associated with this project will result in an increase in demand on police protection
services. Additionally, the Sheriff’s Department encouraged the use of design features in the project
that are consistent with the “Crime Prevention Through Environmental Design” techniques.
Any incremental effects of the project on police protection services will be offset by the City
requirement for payment of fees to a preexisting Community Facilities District for police protection.
Therefore, impacts to police protection services are determined to be less than significant.
c) Schools? Less than Significant Impact
The project is located within the service boundary of the San Marcos Unified School District
(SMUSD). Existing schools that would serve the project include:
• Discovery Elementary School, 730 Applewilde Drive
• San Elijo Elementary School, 1615 School House Way
• San Elijo Middle School, 600 School House Way
• San Marcos High School, 1615 San Marcos Boulevard
The current enrollment and planned capacity of each of these schools is presented below. Due to
overcrowding in the district, interim relocatable classrooms are used at various sites in the district.
Additionally, some students are house at schools outside their attendance area and may be bussed
to those sites.
Heart of the City Specific Plan Amendment (Rancho Coronado) 93 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
School Enrollment Permanent Capacity
Discovery Elementary School 987 638
San Elijo Elementary School 1,225 838
San Elijo Middle School 1,499 1,484
San Marcos High School 2,242 2,961
Based upon correspondence from SMUSD (2012) (Appendix L), development of 346 residential units
is expected to generate approximately 86 elementary school students, 37 middle school students
and 44 high school students. Based upon the available capacity at the schools that would serve the
project, student generation associated with the project would exceed current capacity at the
elementary and middle schools. These additional students would need to be accommodated
through the addition of classrooms on these campuses, or within the increase capacity generated by
future K-8 school planned within the District. The project applicant will be required to pay school
mitigation fees pursuant to California Education Code Section 17620 and Government Code Section
65995. These fees will assist in funding the SMUSD’s long-rage plans. Current Level II school fees are
$4.58/s.f. for residential and $0.51/s.f. for commercial.
d) Parks? Less than Significant Impact
The City has 22 developed parks as well an extensive trail network. The closest existing park to the
project site is Double Peak Park (900 Double Peak Drive), which is approximately 2.5 miles south of
the project site. Double Peak Park includes picnic area, trails, a playground, amphitheater, scenic
views and restroom facilities. The future South Lake Park will be located immediately south of the
project site. South Lake Park will include a dog park, picnic area, scenic viewing, trails, and restroom
facilities. South Lake Park is scheduled to open is included in the City’s Capital Improvement
Program but an opening date is yet to be determined.
The project proposes 38.43 acres of active park area that would be developed in the future with a
variety of active park uses, including ball fields. The proposed park facility will add to the overall
park and recreation amenities in the City. Therefore impacts are less than significant.
e) Other public facilities? Less than Significant Impact
In Sections XIV(a) through XIV(d), the analysis concluded that the project would have a less than
significant impact related to police protection, fire protect, schools and parks. The project would not
result in an impact to any other public facilities. Impacts are less than significant.
XV. RECREATION
a) Would the project increase the use of existing neighborhood and regional parks or other
recreational facilities, such that substantial physical deterioration of the facility would occur
or be accelerated? Less than Significant Impact
The City has 22 developed parks as well an extensive trail network. The closest existing park to the
project site is Double Peak Park (900 Double Peak Drive), which is approximately 2.5 miles south of
the project site. Double Peak Park includes picnic area, trails, a playground, amphitheater, scenic
Heart of the City Specific Plan Amendment (Rancho Coronado) 94 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
views and restroom facilities. The future South Lake Park will be located immediately south of the
project site. South Lake Park will include a dog park, picnic area, scenic viewing, trails, and restroom
facilities.
The project proposes over 38 acres of active park area that would be developed in the future with a
variety of active park uses, including ball fields. The proposed park facility will add to the overall
park and recreation amenities in the City.
Since the project provides adequate recreational amenities, the project would not result in
substantial physical deterioration of any facilities and impacts are less than significant.
b) Does the project include recreational facilities or require the construction or expansion of
recreational facilities, which might have an adverse physical effect on the environment? Less
Than Significant Impact
The project includes approximately 38-acres of active park are which would be developed at a
future time. Additionally small pocket parks are incorporated into the residential area. Any
impacts associated with these uses are analyzed within this environmental document. Impacts
are less than significant.
XVI. TRANSPORTATION/TRAFFIC
A traffic impact analysis was prepared for the project by RBF Consulting (2014). The complete report
is included as Appendix M of this document. The project study area included 11 intersections and 12
roadway segments and considered the following analysis scenarios:
• Existing Conditions
• Existing Plus Project Conditions
• Year 2016 Cumulative Conditions Without Project
• Year 2016 Cumulative Conditions With Project (Phase One)
• Year 2020 Cumulative Conditions Without Project
• Year 2020 Cumulative Conditions With Project (Phase Two)
• Horizon Year 2030 Conditions Without Project
• Horizon Year 2030 Conditions With Project (Phase Two)
a) Cause an increase in traffic, which is substantial in relation to the existing traffic load and
capacity of the street system (i.e., result in a substantial increase in either the number of
vehicle trips, the volume to capacity ratio on roads, or congestion at intersections)? Less Than
Significant With Mitigation Incorporated
Existing Level of Service
To determine the existing operation of the study intersections, intersection turning movement
counts were taken on a typical weekday during the a.m. (7:00 to 9:00 a.m.) and p.m. (4:00 to 6:00
p.m.) peak period. Table 21 summarizes the existing a.m. and p.m. peak hour intersection LOS of
the study intersections based on the existing peak hour intersection volumes and existing
intersection geometry. As shown in Table 21, all study intersections currently operate at acceptable
levels of service (LOS D) or better during the peak hours.
Heart of the City Specific Plan Amendment (Rancho Coronado) 95 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 21. Existing Peak Hour Intersection Conditions
Study Intersection
Existing Conditions
AM Delay (1)
–
LOS
PM Delay (1)
–
LOS
Twin Oaks Valley Rd / SR-78 WB Ramps 14.7 – B 17.1 – B
Twin Oaks Valley Rd / SR-78 EB Ramps 33.4 - C 31.6 – C
Twin Oaks Valley Rd / Discovery St – Barham Dr 27.2 – C 31.6 – C
Twin Oaks Valley Rd / Campus Marketplace 13.7 – B 20.8 – C
Twin Oaks Valley Rd / Craven Rd 25.3 – C 34.7 – C
Twin Oaks Valley Rd / North Village Dr 23.8 – C 25.1 – C
Twin Oaks Valley Rd / South Village Dr 6.0 – A 6.1 – A
Craven Rd / Rush Dr 29.9 – C 36.0 – D
Craven Rd / Echo Lane 12.6 – B 10.8 – B
Craven Rd / Santa Barbara Dr (2)
11.3 – B 14.2 – B
Note: Deficient intersection operation indicated in bold. (1)
Seconds of delay per vehicle. (2)
Unsignalized, two-way stop-sign controlled intersection.
Daily roadway segment levels of service were calculated based on the roadway classification and
capacity as well as existing ADT volumes. Table 22 presents the results of the existing conditions
daily roadway segment level of service analysis. As shown in Table 22, all study roadway segments
currently operate at acceptable levels of service (LOS D or better).
Table 22. Existing Daily Roadway Segment Conditions
Roadway Location
Class
(# Lanes)
LOS E
Capacity
Existing
ADT V/C LOS
Twin Oaks
Valley Rd.
SR-78 Ramps to Barham Dr./ Discovery St. Prime (8) 70,000 39,465 0.564 B
Barham Dr./Discovery St. to Campus Marketplace Prime (6) 60,000 28,659 0.478 B
Campus Marketplace to Craven Rd. Prime (6) 60,000 29,990 0.500 B
Craven Rd. to North Village Dr. Prime (6) 60,000 21,750 0.363 A
North Village Dr. to South Village Dr. Prime (6) 60,000 17,491 0.292 A
South of South Village Dr. Major (5) 45,000 17,056 0.379 A
Craven Rd.
Twin Oaks Valley Rd. to Rush Dr. Major (4) 40,000 10,294 0.257 A
Rush Dr. to Echo Lane Major (4) 40,000 15,746 0.394 B
Echo Lane to Santa Barbara Dr. Major (4) 40,000 16,013 0.400 B
Santa
Barbara Dr. Craven Rd. to Orchid Ave. Collector (2) 8,000 1,181 0.148 A
North
Village Dr. Carnation Court to Twin Oaks Valley Rd. Collector (2) 8,000 1,038 0.130 A
Note: Deficient roadway segment operation shown in bold.
Heart of the City Specific Plan Amendment (Rancho Coronado) 96 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Project Trip Generation
To determine the trips forecast to be generated by the proposed project, April 2002 SANDAG Trip
Generation rates were utilized in accordance with the City of San Marcos and SANTEC/ITE Traffic
Study Guidelines. As shown in Table 23, Phase One of the proposed project will generate
approximately 1,260 trips per day, which includes approximately 101 a.m. peak hour trips and
approximately 126 p.m. peak hour trips. Phase Two (project build-out including Phase One) will
generate approximately 8,926 trips per day, which includes approximately 857 a.m. peak hour trips
and approximately 942 p.m. peak hour trips.
Table 23. Proposed Project Trip Generation
Land Use Units
Daily
(per unit)
AM Peak PM Peak
Total In Out Total In Out
Single Family Residential DU 10 8% 30% 70% 10% 70% 30%
Active Park AC 30 13% 50% 50% 9% 50% 50%
Business Park TSF 16 12% 80% 20% 12% 20% 80%
Specialty Retail TSF 40 3% 60% 40% 9% 50% 50%
Land Use Size Unit
Daily
Trips
AM Peak PM Peak
Total In Out Total In Out
Forecast Project Generated Trips
Phase One (2016)
Single Family Residential 126 DU 1,260 101 30 71 126 88 38
Total Phase I Trips 1,260 101 30 71 126 88 38
Phase Two - Includes Phase One Development (2020)
Single Family Residential 346 DU 3,460 277 83 194 346 242 104
Active Park 35 AC 1,050 137 68 68 95 47 47
Business Park (MU-4 site) 216 TSF 3,456 415 332 83 415 83 332
Specialty Retail (MU-4 site) 24 TSF 960 29 17 12 86 43 43
Total Project Trips 8,926 857 500 356 942 416 526
Source: SANDAG (Not So) Brief Guide of Vehicular Traffic Generation Rates for the San Diego Region (April 2002).
Existing + Project Condition Analysis
Existing plus project conditions evaluates the impact of the build-out of the proposed project
(completion of Phase One and Phase Two) on the existing roadway network. The Phase Two project
trip distribution assumes that a total of 10% of the project trips will remain internal to the site, with
approximately 5 percent of the trips being captured between the residential and park uses, and
approximately 5 percent of the trips being captured between the residential and business
park/retail use.
The addition of project-generated trips is not forecast to result in a change in operating conditions
from acceptable to deficient at any of the study intersections. As shown in Table 24, consistent with
existing conditions, the study intersections are forecast to continue operating at LOS D or better
with the addition of traffic generated by the proposed project.
Heart of the City Specific Plan Amendment (Rancho Coronado) 97 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 24. Existing Plus Project Peak Hour Intersection Conditions
Study Intersection
Existing Conditions Existing + Project
Change
in Delay(1)
AM Delay(1)
LOS
PM Delay(1)
LOS
AM Delay(1)
LOS
PM Delay(1)
LOS AM PM
Twin Oaks Valley Rd / SR-78 WB Ramps 20.2 – C 17.1 – B 20.8 – C 17.9 – B 0.6 0.8
Twin Oaks Valley Rd / SR-78 EB Ramps 33.4 – C 29.0 - C 37.7 - D 31.5 - C 4.3 2.5
Twin Oaks Valley Rd / Discovery St – Barham Dr 31.2 – C 31.6 – C 31.2 – C 31.6 – C 0.0 0.0
Twin Oaks Valley Rd / Campus Marketplace 14.3 – B 20.8 – C 14.3 – B 20.8 – C 0.0 0.0
Twin Oaks Valley Rd / Craven Rd 29.2 – C 34.7 – C 29.2 – C 35.9 – D 0.0 1.2
Twin Oaks Valley Rd / North Village Dr 27.1 – C 25.1 – C 30.6 – C 26.0 – C 3.5 0.9
Twin Oaks Valley Rd / South Village Dr 6.4 – A 6.1 – A 15.7 – B 20.3 – C 9.3 14.2
Craven Rd / Rush Dr 34.7 – C 36.0 – D 34.7 – C 36.7 – D 0.0 0.7
Craven Rd / Echo Ln 12.8 – B 10.8 – B 14.2 – B 11.0 – B 1.4 0.2
Craven Rd / Santa Barbara Dr (2)
11.3 – B 14.2 – B 12.3 – B 16.3 – C 1.0 2.1
Twin Oaks Valley Rd / South Project Access – – 5.6 – A 11.2 – B – –
Note: Deficient intersection operation shown in bold. (1)
Seconds of delay per vehicle. (2)
Unsignalized, two-way stop-sign controlled intersection.
The results of the Existing Plus Project conditions daily roadway segment analysis is presented in
Table 25. Table 25 shows that consistent with existing conditions, all study roadway segments are
forecast to operate at LOS D or better with the addition of project-generated trips to existing daily
roadway segment volumes and impacts are less than significant.
Year 2016 Cumulative Conditions – With and Without Project Analysis
To determine the Year 2016 Cumulative conditions in the project study area, forecast project traffic
associated with City of San Marcos approved or pending projects was added to existing traffic
volumes. Cumulative project traffic data through the study area is based on information from traffic
impact studies. Cumulative projects are forecast to generate approximately 52,861 trips per day,
which includes approximately 4,553 a.m. peak hour trips and approximately 5,194 p.m. peak hour
trips.
Year 2016 Cumulative Conditions Level of Service Analysis
Table 26 summarizes the Year 2016 Cumulative conditions peak hour intersection analysis using
HCM methodology, without and with the proposed project. As shown in Table 26, all intersections
are forecast to operate at LOS D or better in the 2016 cumulative peak hour condition.
Heart of the City Specific Plan Amendment (Rancho Coronado) 98 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 25. Existing Plus Project Daily Roadway Segment Conditions
Segment Location
Class
(# Lanes)
LOS E
Capacity
Existing Existing + Project Change
in V/C ADT V/C LOS ADT V/C LOS
Twin Oaks
Valley Rd.
SR-78 Ramps to Barham Dr./
Discovery St. Prime (8) 70,000 39,465 0.564 B 43,136 0.616 C 0.052
Barham Dr./Discovery St. to
Campus Marketplace Prime (6) 60,000 28,659 0.478 B 32,635 0.544 B 0.066
Campus Marketplace to Craven Rd. Prime (6) 60,000 29,990 0.500 B 34,195 0.570 B 0.070
Craven Rd. to North Village Dr. Prime (6) 60,000 21,750 0.363 A 26,531 0.442 B 0.080
North Village Dr. to South Village Dr. Prime (6) 60,000 17,491 0.292 A 21,009 0.350 A 0.059
South Village Dr. to South Project-
Park Access Major (5) 45,000 17,056 0.379 A 19,329 0.430 B 0.051
South of South Project Access Major (5) 45,000 17,056 0.379 A 18,976 0.422 B 0.043
Craven Rd.
Twin Oaks Valley Rd. to Rush Dr. Major (4) 40,000 10,294 0.257 A 11,090 0.277 A 0.020
Rush Dr. to Echo Lane Major (4) 40,000 15,746 0.394 B 16,725 0.418 B 0.024
Echo Lane to Santa Barbara Dr. Major (4) 40,000 16,013 0.400 B 17,445 0.436 B 0.036
Santa Barbara Dr. Craven Rd. to Orchid Avenue Collector (2) 8,000 1,181 0.148 A 2,409 0.301 A 0.153
North Village Dr. Twin Oaks Valley Road to
Carnation Court Collector (2) 8,000 1,038 0.130 A 3,188 0.399 B 0.269
Note: Deficient roadway segment operation shown in bold.
Heart of the City Specific Plan Amendment (Rancho Coronado) 99 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 26. Year 2016 Cumulative Peak Hour Intersection Conditions - Without and With Project
Study Intersection
Without Project With Project
Change in
Delay(1)
AM Delay(1)
LOS
PM Delay(1)
LOS
AM Delay(1
LOS
PM Delay(1)
LOS AM PM
Twin Oaks Valley Rd / SR-78 WB Ramps 21.0 – C 18.6 – B 21.0 – C 18.8 – B 0.0 0.2
Twin Oaks Valley Rd / SR-78 EB Ramps 40.1 - D 34.3 - C 40.8 - D 35.0 - D 0.7 0.7
Twin Oaks Valley Rd / Discovery St-Barham Dr 33.4 – C 39.9 – D 33.5 – C 40.1 – D 0.1 0.2
Twin Oaks Valley Rd / Campus Marketplace 16.9 – B 23.8 - C 16.9 – B 24.0 – C 0.0 0.2
Twin Oaks Valley Rd / Craven Rd 33.1 – C 39.8 – D 33.2 – C 40.5 – D 0.1 0.7
Twin Oaks Valley Rd / North Village Dr 26.3 – C 24.9 – C 27.3 – C 25.1 – C 1.0 0.2
Twin Oaks Valley Rd / South Village Dr 7.2 – A 6.1 – A 7.2 – A 6.1 – A 0.0 0.0
Craven Rd / Rush Dr 36.5 – D 42.2 – D 36.7 – D 43.5 – D 0.2 1.3
Craven Rd / Echo Ln 13.0 – B 15.8 – B 13.1 – B 15.9 – B 0.1 0.1
Craven Rd / Santa Barbara Dr (2)
12.5 – B 16.6 – C 13.1– B 17.5 – C 0.6 0.9
Twin Oaks Valley Rd / South Project Access – – – – – –
Note: Deficient intersection operation shown in bold. Change in delay shown in bold indicates a significant impact. (1)
Seconds of delay per vehicle. (2)
Unsignalized, two-way stop-sign controlled intersection.
Daily roadway segment levels of service were calculated based on the roadway classification and
capacity as well as ADT volumes. Table 27 presents the results of the Year 2016 Cumulative
conditions roadway segment level of service analysis, without and with the proposed project. As
shown in Table 27, all study roadway segments are forecast to operate at acceptable levels of
service (LOS D or better) both without and with the proposed project under Year 2016 Cumulative
Conditions.
Year 2016 Cumulative Conditions – With and Without Project Analysis
To determine the Year 2016 Cumulative conditions in the project study area, forecast project traffic
associated with City of San Marcos approved or pending projects was added to existing traffic
volumes. Cumulative project traffic data through the study area is based on information from traffic
impact studies. Cumulative projects are forecast to generate approximately 52,861 trips per day,
which includes approximately 4,553 a.m. peak hour trips and approximately 5,194 p.m. peak hour
trips.
Year 2016 Cumulative Conditions Level of Service Analysis
Table 26 summarizes the Year 2016 Cumulative conditions peak hour intersection analysis using
HCM methodology, without and with the proposed project. As shown in Table 26, all intersections
are forecast to operate at LOS D or better in the 2016 cumulative peak hour condition.
Heart of the City Specific Plan Amendment (Rancho Coronado) 100 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 27. Year 2016 Cumulative Daily Roadway Segment Conditions - Without and With Project
Segment Location
Class
(# Lanes)
LOS E
Capacity
Year 2016 Without
Project Year 2016 With Project Change
in V/C ADT V/C LOS ADT V/C LOS
Twin Oaks
Valley Rd.
SR-78 Ramps to Barham Dr./ Discovery St. Prime (8) 70,000 48,534 0.693 C 49,076 0.701 C 0.008
Barham Dr./Discovery St. to
Campus Marketplace Prime (6) 60,000 33,364 0.556 B 33,855 0.564 B 0.008
Campus Marketplace to Craven Rd. Prime (6) 60,000 34,489 0.575 B 35,056 0.584 C 0.009
Craven Rd. to North Village Dr. Prime (6) 60,000 29,678 0.495 B 30,081 0.501 B 0.007
North Village Dr. to South Village Dr. Prime (6) 60,000 25,017 0.417 B 25,307 0.422 B 0.005
South Village Dr. to South Project Access Major (5) 45,000 24,681 0.548 B 24,971 0.555 B 0.006
South of South Project Access Major (5) 45,000 24,681 0.548 B 24,971 0.555 B 0.006
Craven Rd.
Twin Oaks Valley Rd. to Rush Dr. Major (4) 40,000 14,702 0.368 A 14,891 0.372 A 0.005
Rush Dr. to Echo Lane Major (4) 40,000 20,928 0.523 B 21,243 0.531 C 0.008
Echo Lane to Santa Barbara Dr. Major (4) 40,000 21,595 0.540 C 22,036 0.551 C 0.011
Santa Barbara Dr. Craven Rd. to Orchid Avenue Collector (2) 8,000 1,253 0.157 A 1,820 0.228 A 0.071
North Village Dr. Twin Oaks Valley Road to
Carnation Court Collector (2) 8,000 1,086 0.136 A 1,779 0.222 A 0.087
Note: Deficient roadway segment operation shown in bold.
Heart of the City Specific Plan Amendment (Rancho Coronado) 101 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Year 2020 Cumulative Conditions – With and Without Project Analysis
To determine the Year 2020 Cumulative conditions in the project study area, forecast project traffic
associated with City of San Marcos approved or pending projects was added to existing traffic
volumes. The cumulative projects are forecast to generate approximately 97,290 trips per day,
which includes approximately 7,652 a.m. peak hour trips and approximately 9,583 p.m. peak hour
trips. To determine the Year 2020 Cumulative operating conditions at the study intersections, the
cumulative project trips were added to the existing volumes at the intersections and roadway
segments within the project study area.
The Year 2020 Cumulative Conditions analysis assumes the completion of the following roadway
improvements within the project study area:
• Extension of Discovery Street from Bent Avenue to Twin Oaks Valley Road, constructed as
six-lane Prime Arterial.
• Intersection improvements at Twin Oaks Valley Road / Discovery Street-Barham Drive:
o Two left-turn lanes, three through lanes and one right-turn lane at westbound
approach
o Removal of existing free-right turn lanes at southbound, eastbound and westbound
approaches, replaced with standard right-turn lanes.
o Right-turn overlap phases provided at southbound and westbound intersection
approaches
• Southbound approach of Twin Oaks Valley Road / Campus Marketplace Access restriped to
provide a second left-turn lane into CSUSM campus parking lot area.
The Discovery Street extension will divert existing traffic away from Craven Road and Rush Drive,
and level of service at the intersection of Craven Road / Rush Drive will improve to an acceptable
LOS C during the peak hours under Year 2020 Cumulative Conditions.
Year 2020 Cumulative Conditions Level of Service Analysis
Table 28 summarizes the Year 2020 Cumulative conditions peak hour intersection analysis using
HCM methodology, without and with the proposed project.
As shown in Table 28, all intersections are forecast to operate at an acceptable level of under Year
2020 Cumulative Conditions both without and with the proposed project:
Heart of the City Specific Plan Amendment (Rancho Coronado) 102 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 28. Year 2020 Cumulative Peak Hour Intersection Conditions Without and With Project
Study Intersection
Without Project With Project
Change in
Delay(1)
AM Delay(1)
LOS
PM Delay(1)
LOS
AM Delay(1)
LOS
PM Delay(1)
LOS AM PM
Twin Oaks Valley Rd / SR-78 WB Ramps 21.7 – C 20.1 – C 22.4 – C 22.8 – C 0.7 2.7
Twin Oaks Valley Rd / SR-78 EB Ramps 43.5 - D 40.9 - D 49.3 - D 48.3 - D 5.8 7.4
Twin Oaks Valley Rd / Discovery St – Barham Dr 29.5 – C 42.2 – D 29.7 – C 49.5 – D 0.2 7.3
Twin Oaks Valley Rd / Campus Marketplace 15.4 – B 24.0 – C 15.4 – B 24.0 – C 0.0 0.0
Twin Oaks Valley Rd / Craven Rd 33.4 – C 39.4 – D 36.0 – D 46.6 – D 2.6 7.2
Twin Oaks Valley Rd / North Village Dr 26.4 – C 25.4 – C 32.0 – C 27.6 – C 5.6 2.2
Twin Oaks Valley Rd / South Village Dr 7.2 – A 6.0 – A 13.8 – B 18.8 – B 6.6 12.8
Craven Rd / Rush Dr 30.2 – C 29.3 – C 30.2 – C 29.7 – C 0.0 0.4
Craven Rd / Echo Ln 14.1 – B 14.6 – B 14.2 – B 14.8 – B 0.2 0.2
Craven Rd / Santa Barbara Dr (2)
11.1 – B 13.0 – B 12.0 – B 14.5 – B 0.9 1.5
Twin Oaks Valley Rd / South Project Access – – 5.6 – A 8.9 – A – –
Note: Deficient intersection operation shown in bold. Change in delay shown in bold indicates a significant impact. (1)
Seconds of delay per vehicle. (2)
Unsignalized, two-way stop-sign controlled intersection.
Daily roadway segment levels of service were calculated based on the roadway classification and
capacity as well as ADT volumes. Table 29 presents the results of the Year 2020 Cumulative
conditions roadway segment level of service analysis, without and with the proposed project. As
shown in Table 28, all study roadway segments are forecast to operate at acceptable levels of
service (LOS D or better) both without and with the proposed project under Year 2020 Cumulative
Conditions.
Horizon Year 2030 Conditions Level of Service Analysis
The results of the Horizon Year 2030 intersection level of service analysis are summarized in
Table 30.
Heart of the City Specific Plan Amendment (Rancho Coronado) 103 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 29. Year 2020 Cumulative Daily Roadway Segment Conditions - Without and With Project
Segment Location
Class
(# Lanes)
LOS E
Capacity
Year 2020 Without
Project Year 2020 With Project
Change
in V/C ADT V/C LOS ADT V/C LOS
Twin Oaks
Valley Rd.
SR-78 Ramps to Barham Dr./ Discovery St. Prime (8) 70,000 51,181 0.731 C 54,561 0.779 C 0.048
Barham Dr./Discovery St. to
Campus Marketplace Prime (6) 60,000 35,219 0.587 C 39,484 0.658 C 0.071
Campus Marketplace to Craven Rd. Prime (6) 60,000 36,256 0.604 C 40,715 0.679 C 0.074
Craven Rd. to North Village Dr. Prime (6) 60,000 31,553 0.526 B 36,746 0.612 C 0.087
North Village Dr. to South Village Dr. Prime (6) 60,000 27,174 0.453 B 30,869 0.514 B 0.062
South Village Dr. to South Project Access Major (5) 45,000 26,838 0.596 C 29,002 0.644 C 0.048
South of South Project Access Major (5) 45,000 26,838 0.596 C 28,560 0.635 C 0.038
Craven Rd.
Twin Oaks Valley Rd. to Rush Dr. Major (4) 40,000 14,140 0.354 A 15,185 0.380 B 0.026
Rush Dr. to Echo Lane Major (4) 40,000 16,482 0.412 B 17,306 0.433 B 0.021
Echo Lane to Santa Barbara Dr. Major (4) 40,000 16,275 0.407 B 17,428 0.436 B 0.029
Santa Barbara Dr. Craven Rd. to Orchid Avenue Collector (2) 8,000 1,253 0.157 A 2,266 0.283 A 0.127
North Village Dr. Twin Oaks Valley Road to
Carnation Court Collector (2) 8,000 1,086 0.136 A 3,472 0.434 B 0.298
Note: Deficient roadway segment operation shown in bold.
Heart of the City Specific Plan Amendment (Rancho Coronado) 104 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 30. Horizon Year 2030 Peak Hour Intersection Conditions - Without and With Project
Study Intersection
Without Project With Project
Change in
Delay(1)
AM Delay(1)
LOS
PM Delay(1)
LOS
AM Delay(1)
LOS
PM Delay(1)
LOS AM PM
Twin Oaks Valley Rd / SR-78 WB Ramps 23.8 – C 24.3 – C 25.0 – C 30.2 – C 1.2 5.9
Twin Oaks Valley Rd / SR-78 EB Ramps 82.4 – F 65.5 – F 94.1 – F 76.0 – F 11.7 10.5
Twin Oaks Valley Rd / Discovery St – Barham Dr 34.4 – C 55.1 – E 35.5 – D 66.0 – E 1.1 10.9
Twin Oaks Valley Rd / Campus Marketplace 16.9 – B 29.0 – C 16.9 – B 29.6 – C 0.0 0.6
Twin Oaks Valley Rd / Craven Rd 30.8 – C 39.6 – D 32.2 – C 45.9 – D 1.4 6.3
Twin Oaks Valley Rd / North Village Dr 27.1 – C 23.9 – C 33.1 – C 26.9 – C 6.0 3.0
Twin Oaks Valley Rd / South Village Dr 7.1 – A 5.9 – A 13.8 – B 18.7 – B 6.7 12.8
Craven Rd / Rush Dr 31.8 – C 32.0 – C 32.1 – C 32.8 – C 0.3 0.8
Craven Rd / Echo Ln 16.0 – B 14.8 – B 16.4 – B 14.9 – B 0.4 0.1
Craven Rd / Santa Barbara Dr (2)
11.5 – B 14.2 – B 12.7 – B 16.0 – C 1.2 1.8
Twin Oaks Valley Rd / South Project Access – – 5.5 – A 8.0 – A – –
Note: Deficient intersection operation shown in bold. Change in delay shown in bold indicates a significant impact. (1)
Seconds of delay per vehicle. (2)
Unsignalized, two-way stop-sign controlled intersection.
As shown in Table 30, the following intersections are forecast to operate at deficient levels of
service (LOS E or F) under Horizon Year 2030 Conditions both without and with the proposed
project:
• Twin Oaks Valley Road / SR-78 Eastbound Ramps (a.m./p.m.: LOS F)
• Twin Oaks Valley Road / Discovery Street–Barham Drive (p.m.: LOS E)
The addition of project-related traffic to the above-listed intersections results in an increase in delay
that exceeds the significance threshold of 2.0 seconds. Therefore, the project will result in a
significant impact at Twin Oaks Valley Road / SR-78 Eastbound Ramps (Impact TR-1) and Twin Oaks
Valley Road / Discovery Street–Barham Drive (Impact TR-2) under Horizon Year 2030 Conditions,
and mitigation measures are required.
MM-TR-1 The project applicant shall make a fair share contribution towards the following
improvements at the Twin Oaks Valley Road/SR-78 Eastbound Ramps:
• Construct an additional dedicated right-turn lane at eastbound (off-ramp)
approach of intersection.
• Restripe eastbound approach to include one left-turn lane, one shared left-
turn/through/right-turn lane, and two right-turn lanes.
MM-TR-2 The project applicant shall make a fair share contribution towards the widening of
the northbound approach of the Twin Oaks Valley Road/Discover Street-Barham
Drive intersection to construct a dedicated right-turn lane.
Heart of the City Specific Plan Amendment (Rancho Coronado) 105 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
The project applicant shall pay fair share payments towards the improvements identified in
MM-TR-1 and MM-TR-2. Implementation of mitigation measure MM-TR-1 will improve the LOS from
F to E in the AM Peak hour, improve LOS in the PM peak hour, and reduce impacts to below a level
of significance.
Implementation of mitigation measure MM-TR-2 will improve the LOS from D to C in the AM peak
hour and E to D in the PM peak hour and reduce impacts to below a level of significance.
Daily roadway segment levels of service were calculated based on the roadway classification and
capacity as well as ADT volumes. Table 31 presents the results of the Horizon Year 2030 Conditions
roadway segment level of service analysis, without and with the proposed project As shown in
Table 31, all study roadway segments are forecast to operate at acceptable levels of service (LOS D
or better) both without and with the proposed project under Horizon Year 2030 Conditions.
Site Access and Internal Circulation
The project will take access from Santa Barbara Drive, North Village Drive, South Village Drive and a
new signalized intersection and access road at the south end of the project site. The residential
units built in Phase One will take access from Santa Barbara Drive and North Village Drive. Phase
One includes construction of the “Backbone Road” that will extend from the existing terminus of
Santa Barbara Drive to the proposed western extension of North Village Drive.
Phase Two will construct the remaining portion of the “Backbone Road from North Village Drive to
the intersection of Twin Oaks Valley Road / South Village Drive. The southerly access intersection,
traffic signal and road will also be constructed during Phase Two to provide access to the proposed
business park and retail uses located at the southern end of the site.
Roundabouts are proposed for the future intersection of North Village Drive / “Backbone Road” and
at another intersection of the “Backbone Road” with a local access street internal to the project site.
A third roundabout is also being considered for the existing intersection of North Village Drive and
Carnation Court, which is located approximately 350 feet west of the signalized intersection of Twin
Oaks Valley Road and North Village Drive. Currently this is a three-legged intersection that is
controlled by stop signs at all approaches. However, there is currently no through traffic on North
Village Drive as the road terminates a few hundred feet west of Carnation Court. One of the
proposed neighborhoods within the project site will take access from North Village Drive across
from Carnation Court, which will add a fourth leg to the intersection of North Village Drive /
Carnation Court. Although the forecast through traffic on North Village Drive at Carnation Court is
relatively low, the existing all-way stop sign control is not optimal due to the close proximity of the
intersection to the signalized intersection at Twin Oaks Valley Road. A roundabout at the North
Village Drive / Carnation Court would improve the flow of traffic through the intersection and
eliminate any potential for queues spilling back from the existing stop signs.
Heart of the City Specific Plan Amendment (Rancho Coronado) 106 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 31. Horizon Year 2030 Daily Roadway Segment Conditions - Without and With Project
Segment Location
Class
(# Lanes)
LOS E
Capacity
Year 2030 Without Project Year 2030 With Project Change
in V/C ADT V/C LOS ADT V/C LOS
Twin Oaks
Valley Rd.
SR-78 Ramps to Barham Dr./ Discovery St. Prime (8) 70,000 59,048 0.844 D 62,428 0.892 D 0.048
Barham Dr./Discovery St. to
Campus Marketplace Prime (6) 60,000 38,564 0.643 C 42,829 0.714 C 0.071
Campus Marketplace to Craven Rd. Prime (6) 60,000 39,665 0.661 C 44,124 0.735 C 0.074
Craven Rd. to North Village Dr. Prime (6) 60,000 42,876 0.715 C 48,069 0.801 C 0.087
North Village Dr. to South Village Dr. Prime (6) 60,000 36,750 0.613 C 40,445 0.674 C 0.062
South Village Dr. to South Project Access Major (5) 45,000 34,937 0.776 C 37,101 0.824 D 0.048
South of South Project Access Major (5) 45,000 34,437 0.765 C 36,159 0.804 D 0.038
Craven Rd.
Twin Oaks Valley Rd. to Rush Dr. Major (4) 40,000 18,365 0.459 B 19,410 0.485 B 0.026
Rush Dr. to Echo Lane Major (4) 40,000 18,229 0.456 B 19,053 0.476 B 0.021
Echo Lane to Santa Barbara Dr. Major (4) 40,000 17,150 0.429 B 18,304 0.458 B 0.029
Santa Barbara Dr. Craven Rd. to Orchid Avenue Collector (2) 8,000 1,299 0.162 A 2,312 0.289 A 0.127
North Village Dr. Twin Oaks Valley Road to Carnation Court Collector (2) 8,000 1,142 0.143 A 3,528 0.441 C 0.298
Note: Deficient roadway segment operation shown in bold.
Heart of the City Specific Plan Amendment (Rancho Coronado) 107 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
b) Exceed, either individually or cumulatively, a level of service standard established by the
county congestion management agency for designated roads or highways? Less Than
Significant With Mitigation Incorporated
The traffic report (RBF Consulting, 2013) included an analysis of Caltrans facilities and this section
summarizes the results.
Caltrans Facilities Analysis – ILV Analysis
The results of the Caltrans ILV analysis are summarized in Table 32. As shown in Table 32, operations
at Twin Oaks Valley Road / SR-78 Eastbound Ramps exceed the Capacity threshold of 1,500
intersecting lane volumes per hour during both the a.m. and p.m. peak hours for Year 2016
Cumulative Conditions through Horizon Year 2030 Conditions both without and with the proposed
project. Operations at the intersection of Twin Oaks Valley Road / SR-78 Westbound Ramps exceed
the Capacity threshold of 1,500 intersecting lane volumes per hour during the p.m. peak hour for
Year 2020 Cumulative Conditions through Horizon Year 2030 Conditions both without and with the
proposed project.
Peak Hour Freeway Segment Analysis
The following segments of SR-78 were evaluated under all study scenarios without and with the
proposed project:
• SR-78 from San Marcos Boulevard interchange to Twin Oaks Valley Road interchange
• SR-78 from Twin Oaks Valley Road interchange to Barham Drive-Woodland Parkway
interchange
A 5 percent heavy truck factor was applied based on information reported by Caltrans for these
segments of SR-78. A measured free-flow speed of 65 mph was used in the HCM calculations for
freeway segments. Auxiliary lanes are included in the freeway segment analysis, which are currently
provided in both directions of travel between the interchange ramps on SR-78 from San Marcos
Boulevard to Twin Oaks Valley Road.
Existing (Year 2010) peak hour freeway segment volumes were provided by Caltrans. To determine
the Existing Plus Project operating conditions on the freeway segments, the project-generated trips
were added to the existing peak hour freeway segment volumes. The results of the Existing and
Existing Plus Project conditions peak hour freeway segment analysis are presented in Table 33.
As shown in Table 33, the study freeway segments currently operate at acceptable levels of service
(LOS D or better) except for Westbound SR-78 from Woodland Parkway to Twin Oaks Valley Road,
which is currently operating at LOS F during the a.m. peak hour and at LOS E during the p.m. peak
hour. Under existing plus project conditions, the study freeway segments will continue operating at
acceptable levels of service except for Westbound SR-78 from Woodland Parkway to Twin Oaks
Valley Road.
Heart of the City Specific Plan Amendment (Rancho Coronado) 108 City of San Marcos
Draft Initial Study/MITIGATED Negative Declaration March 2014
Table 32. Caltrans ILV Analysis Summary
Intersection
Without Project With Project
AM Peak Hour PM Peak Hour AM Peak Hour PM Peak Hour
Flow Operations Flow Operations Flow Operations Flow Operations
Existing Conditions
Twin Oaks Valley Rd./ SR-78 WB Ramps 708 Stable 845 Stable 804 Stable 976 Stable
Twin Oaks Valley Rd./ SR-78 EB Ramps 1,346 Unstable 1,160 Stable 1,494 Unstable 1,323 Unstable
Year 2016 Cumulative Conditions
Twin Oaks Valley Rd./ SR-78 WB Ramps 861 Stable 1,082 Stable 875 Stable 1,097 Stable
Twin Oaks Valley Rd./ SR-78 EB Ramps 1,613 Capacity 1,465 Unstable 1,632 Capacity 1,486 Unstable
Year 2020 Cumulative Conditions
Twin Oaks Valley Rd./ SR-78 WB Ramps 922 Stable 1,210 Unstable 1,003 Stable 1,322 Unstable
Twin Oaks Valley Rd./ SR-78 EB Ramps 1,708 Capacity 1,635 Capacity 1,834 Capacity 1,776 Capacity
Horizon Year 2030 Conditions
Twin Oaks Valley Rd./ SR-78 WB Ramps 1,126 Stable 1,347 Unstable 1,208 Unstable 1,459 Unstable
Twin Oaks Valley Rd./ SR-78 EB Ramps 2,155 Capacity 1,850 Capacity 2,281 Capacity 1,991 Capacity
Note: ILV operations at capacity indicated in bold.
Heart of the City Specific Plan Amendment (Rancho Coronado) 109 City of San Marcos
Draft Initial Study/MITIGATED Negative Declaration March 2014
Table 33. Peak Hour Freeway Segment Analysis Existing / Existing Plus Project Conditions
Freeway From To
Existing Conditions Existing Plus Project Conditions Change
in Speed
(mph) Volume LOS
Speed
(mph) D Volume LOS
Speed
(mph) D
AM Peak Hour
SR-78 EB San Marcos ON TOVR OFF 5,073 C 65.0 21.0 5,159 C 65.0 21.4 0.0
SR-78 WB TOVR ON San Marcos OFF 6,278 D 64.6 26.2 6,329 D 64.5 26.5 -0.1
SR-78 EB TOVR ON Barham OFF 5,129 D 63.5 29.1 5,191 D 63.3 29.5 -0.2
SR-78 WB Woodland ON TOVR OFF 6,616 F * * 6,707 F * * *
PM Peak Hour
SR-78 EB San Marcos ON TOVR OFF 5,480 C 65.0 22.7 5,544 C 65.0 23.0 0.0
SR-78 WB TOVR ON San Marcos OFF 5,671 C 65.0 23.5 5,764 C 65.0 23.9 0.0
SR-78 EB TOVR ON Barham OFF 5,710 D 60.5 34.0 5,809 D 59.8 35.0 -0.7
SR-78 WB Woodland ON TOVR OFF 6,048 E 57.7 37.7 6,125 E 57.0 38.7 -0.7
Note: Deficient freeway segment operation indicated in bold where applicable.
D =Density, Passenger Cars per Mile per Lane
Heart of the City Specific Plan Amendment (Rancho Coronado) 110 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Year 2016 and year 2030 peak hour freeway segment volumes are based on traffic volumes and
forecasts developed by Caltrans District 11 Office of Advanced Planning and are consistent with
traffic forecast volumes used on the recent auxiliary lane studies on SR-78 between San Marcos
Boulevard and Woodland Parkway, and between Woodland Parkway and Nordahl Road. The
forecast growth on each freeway segment was calculated from 2016 to 2030, and annual growth
rates were applied to each freeway segment to develop the forecast freeway volumes in the year
2020. Forecast a.m. and p.m. trips generated by the proposed project were added to the Year 2016,
year 2020 and year 2030 base freeway segment volumes.
The SANDAG 2050 Regional Transportation Plan (RTP) includes the construction of one Managed
Lane in each direction of travel on SR-78 from I-5 to I-15 in the Revenue Constrained Plan. The SR-
78 Managed Lanes Project is programmed to be completed by the year 2020. Therefore, this
planned improvement is included in the Year 2020 Cumulative Conditions and Horizon Year 2030
Conditions analysis.
The City of San Marcos in conjunction with Caltrans proposes to construct new auxiliary lanes in
both directions on SR-78 between the San Marcos Boulevard interchange and Woodland
Parkway/Barham Drive interchange, and extending through the Twin Oaks Valley Road interchange.
The proposed auxiliary lanes project on SR-78 is not currently funded, but the project is supported
by SANDAG and funding to construct this project is currently being pursued.
The proposed new auxiliary lanes on SR-78 are assumed to be constructed after Year 2016 but prior
to year 2020. It is assumed that when the SR-78 Managed Lanes Project is completed by 2020, the
new auxiliary lanes would be converted to through traffic lanes to construct the Managed Lane
adjacent to the center median in both directions of travel.
Table 34 summarizes the results of the Year 2016 Cumulative conditions freeway segment analysis
without and with the proposed project, which assumes the existing freeway capacity. As shown in
Table 34, the study freeway segments are forecast to operate at acceptable levels of service (LOS D
or better) under Year 2016 Cumulative conditions except for the following:
• Eastbound SR-78 from Twin Oaks Valley Road to Woodland Parkway-Barham Drive (AM/PM:
LOS E)
• Westbound SR-78 from Woodland Parkway-Barham Drive to Twin Oaks Valley Road
(AM/PM: LOS F)
The Year 2020 Cumulative conditions freeway segment analysis without and with the proposed
project is presented in Table 35, which assumes the construction of the programmed Managed
Lanes Project on SR-78. It is assumed that the proposed new auxiliary lanes would be converted to
through traffic lanes to construct the Managed Lane adjacent to the center median in both
directions of travel. As shown in Table 35, the study freeway segments are forecast to operate at
acceptable levels of service (LOS D or better) under Year 2020 Cumulative conditions both without
and with the proposed project.
Heart of the City Specific Plan Amendment (Rancho Coronado) 111 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 34. Peak Hour Freeway Segment Analysis Year 2016 Cumulative Conditions
Freeway From To
Without Project With Project Change in Speed
(mph) Volume LOS Speed (mph) D Volume LOS
Speed (mph) D
AM Peak Hour
SR-78 EB San Marcos ON TOVR OFF 5,883 C 64.9 24.5 5,888 C 64.9 24.5 0.0
SR-78 WB TOVR ON San Marcos OFF 6,774 D 63.7 28.7 6,785 D 63.6 28.8 -0.1
SR-78 EB TOVR ON Barham OFF 5,945 E 58.6 36.5 5,959 E 58.5 36.6 -0.1
SR-78 WB Woodland ON TOVR OFF 7,083 F * * 7,089 F * * *
PM Peak Hour
SR-78 EB San Marcos ON TOVR OFF 6,365 D 64.5 26.6 6,378 D 64.4 26.7 -0.1
SR-78 WB TOVR ON San Marcos OFF 6,108 C 64.8 25.5 6,114 C 64.7 25.5 -0.1
SR-78 EB TOVR ON Barham OFF 6,611 F * * 6,619 F * * *
SR-78 WB Woodland ON TOVR OFF 6,488 E 52.8 44.2 6,506 E 52.6 44.4 -0.2
Note: Deficient freeway segment operation indicated in bold where applicable.
D =Density, Passenger Cars per Mile per Lane
Heart of the City Specific Plan Amendment (Rancho Coronado) 112 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 35. Peak Hour Freeway Segment Analysis Year 2020 Cumulative Conditions
Freeway From To
Without Project With Project Change
in Speed
(mph) Volume LOS
Speed
(mph) D Volume LOS
Speed
(mph) D
AM Peak Hour
SR-78 EB San Marcos ON TOVR OFF 6,319 C 65.0 21.0 6,390 C 65.0 21.2 0.0
SR-78 WB TOVR ON San Marcos OFF 7,144 C 65.0 23.7 7,185 C 65.0 23.9 0.0
SR-78 EB TOVR ON Barham OFF 6,381 D 64.4 26.7 6,436 D 64.4 27.0 0.0
SR-78 WB Woodland ON TOVR OFF 7,459 D 61.2 32.9 7,540 D 60.8 33.4 -0.4
PM Peak Hour
SR-78 EB San Marcos ON TOVR OFF 6,738 C 65.0 22.4 6,790 C 65.0 22.5 0.0
SR-78 WB TOVR ON San Marcos OFF 6,618 C 65.0 22.0 6,696 C 65.0 22.2 0.0
SR-78 EB TOVR ON Barham OFF 6,997 D 63.0 29.9 7,086 D 62.8 30.5 -0.2
SR-78 WB Woodland ON TOVR OFF 6,973 D 63.1 29.8 7,042 D 62.9 30.2 -0.2
Note: Deficient freeway segment operation indicated in bold where applicable.
D =Density, Passenger Cars per Mile per Lane
Heart of the City Specific Plan Amendment (Rancho Coronado) 113 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 36 summarizes the results of the Horizon Year 2030 conditions freeway segment analysis
without and with the proposed project, which assumes the construction of the programmed
Managed Lanes Project on SR-78. As shown in Table 36, the study freeway segments are forecast to
operate at acceptable levels of service (LOS D or better) under Horizon Year 2030 conditions except
for the following:
• Eastbound SR-78 from Twin Oaks Valley Road to Woodland Parkway-Barham Drive (PM: LOS
E)
• Westbound SR-78 from Woodland Parkway-Barham Drive to Twin Oaks Valley Road
(AM/PM: LOS E)
Peak Hour Freeway Ramp Metering Analysis
Freeway ramp meters are currently operating at the northbound to westbound SR-78 on-ramp at
Twin Oaks Valley Road, the southbound to westbound SR-78 on-ramp at Twin Oaks Valley Road, and
the eastbound SR-78 on-ramp at Twin Oaks Valley Road. The southbound to westbound SR-78 on-
ramp at Twin Oaks Valley Road is not included in this analysis because trips associated with the
proposed project would not be added to this on-ramp.
The northbound to westbound SR-78 on-ramp at Twin Oaks Valley Road has ramp meters operating
during the a.m. peak period from 5:30 a.m. to 9:30 a.m. Ramp meters are currently operating
during the p.m. peak period from 3:30 p.m. to 7:00 p.m. at the eastbound SR-78 on-ramp at Twin
Oaks Valley Road.
The existing lane configurations and meter flow rates for each study area freeway on-ramp are as
follows:
Twin Oaks Valley Road Westbound On-Ramp from NB Approach (a.m. peak metering)
• One single-occupancy vehicle (SOV) lane / One high-occupancy vehicle (HOV) lane
• Meter flow rate: 570 vehicles per hour per lane (2 cars per green)
Twin Oaks Valley Road Eastbound On-Ramp (p.m. peak metering)
• Two single-occupancy vehicle (SOV) lanes / One high-occupancy vehicle (HOV) lane
• Meter flow rate: 570 vehicles per hour per lane (2 cars per green)
It is assumed that the current hourly ramp meter flow rate will be maintained in the future study
scenarios. This assumption is conservative because there are planned improvements on SR-78
through the study area that will increase freeway capacity and improve peak hour flow and level of
service. The existing ramp meter rates are based on the existing capacity and operations, and with
capacity improvements to the freeway, it is likely that the future ramp meter rates would be
adjusted.
Table 37 summarizes the results of the ramp metering analysis under all analysis scenarios. As
shown in Table 37, the peak hour demand at the study ramp meters currently does not exceed the
hourly meter flow rate capacities shown in the table. Table 37 shows that the addition of project-
related traffic to existing ramp volumes will not result in peak hour demand exceeding the hourly
meter flow rate capacities; therefore, no delay or queue lengths were calculated at the ramp meters
under Existing Plus Project conditions.
Heart of the City Specific Plan Amendment (Rancho Coronado) 114 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 36. Peak Hour Freeway Segment Analysis Horizon Year 2030 Conditions
Freeway From To
Without Project With Project Change
in Speed
(mph) Volume LOS
Speed
(mph) D Volume LOS
Speed
(mph) D
AM Peak Hour
SR-78 EB San Marcos ON TOVR OFF 7,192 C 65.0 23.9 7,263 C 64.9 24.1 -0.1
SR-78 WB TOVR ON San Marcos OFF 7,883 D 64.5 26.4 7,924 D 64.5 26.5 0.0
SR-78 EB TOVR ON Barham OFF 7,254 D 62.1 31.5 7,309 D 61.9 31.9 -0.2
SR-78 WB Woodland ON TOVR OFF 8,210 E 56.6 39.1 8,291 E 56.0 39.9 -0.6
PM Peak Hour
SR-78 EB San Marcos ON TOVR OFF 7,483 C 64.8 24.9 7,535 C 64.8 25.1 0.0
SR-78 WB TOVR ON San Marcos OFF 7,637 C 64.8 25.5 7,715 C 64.7 25.7 -0.1
SR-78 EB TOVR ON Barham OFF 7,770 E 59.6 35.2 7,859 E 59.1 35.9 -0.5
SR-78 WB Woodland ON TOVR OFF 7,944 E 58.5 36.6 8,013 E 58.1 37.2 -0.4
Note: Deficient freeway segment operation indicated in bold where applicable.
D =Density, Passenger Cars per Mile per Lane
Heart of the City Specific Plan Amendment (Rancho Coronado) 115 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 37. Peak Hour Freeway Ramp Metering Analysis
Ramp
Peak
Hour
Demand
(Ramp
Volume)
Meter
Flow Rate(1)
Number
of Lanes(2)
Excess
Demand
Delay
(Minutes)
Queue
Length
(in feet)
Existing Conditions
TOVR WB On-Ramp AM 378 570 1.1 0 0 0
TOVR EB On-Ramp PM 939 570 2.2 0 0 0
Existing Plus Project Conditions
TOVR WB On-Ramp AM 429 570 1.1 0 0 0
TOVR EB On-Ramp PM 1,038 570 2.2 0 0 0
Year 2016 Cumulative Conditions Without Project
TOVR WB On-Ramp AM 459 570 1.1 0 0 0
TOVR EB On-Ramp PM 1,145 570 2.2 0 0 0
Year 2016 Cumulative Conditions With Project
TOVR WB On-Ramp AM 470 570 1.1 0 0 0
TOVR EB On-Ramp PM 1,153 570 2.2 0 0 0
Year 2020 Cumulative Conditions Without Project
TOVR WB On-Ramp AM 487 570 1.1 0 0 0
TOVR EB On-Ramp PM 1,242 570 2.2 0 0 0
Year 2020 Cumulative Conditions With Project
TOVR WB On-Ramp AM 528 570 1.1 0 0 0
TOVR EB On-Ramp PM 1,331 570 2.2 29 3 724
Horizon Year 2030 Conditions Without Project
TOVR WB On-Ramp AM 597 570 1.1 0 0 0
TOVR EB On-Ramp PM 1,537 570 2.2 122 13 3,041
Horizon Year 2030 Conditions With Project
TOVR WB On-Ramp AM 638 570 1.1 4 0 105
TOVR EB On-Ramp PM 1,626 570 2.2 162 17 4,043
Notes: (1)
Vehicles per hour per lane. (2)
Previous studies have shown that HOV lanes are utilized by approximately 10% of the total freeway traffic during the peak
hours. The capacity of the SOV and HOV lanes on the ramps were calculated based on the proportion of traffic using each
lane.
It is assumed that the current hourly ramp meter flow rate will be maintained in the future study
scenarios.
The results of the Year 2016 Cumulative Conditions analysis show that the peak hour demand is not
forecast to exceed the current hourly meter flow rate capacities either without or with the proposed
project. Therefore, no delay or queue lengths were calculated at the ramp meters under Year 2016
Cumulative conditions.
As shown in Table 37, the p.m. peak hour demand at the Twin Oaks Valley Road Eastbound On-
Ramp is forecast to exceed the current hourly meter flow rate capacities under Year 2020
Cumulative Conditions with the proposed project. The forecast ramp meter delay is less than 15
minutes and therefore is not considered deficient an excessive delay.
The results of the Horizon Year 2030 Conditions ramp meter analysis show that the p.m. peak hour
Heart of the City Specific Plan Amendment (Rancho Coronado) 116 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
demand at the Twin Oaks Valley Road Eastbound On-Ramp is forecast to exceed the current hourly
meter flow rate capacities either without or with the proposed project. The forecast ramp meter
delay with the proposed project is more than 15 minutes and therefore is considered deficient an
excessive delay according to SANTEC/ITE TIS Guidelines.
Queuing Analysis
A queuing analysis was conducted during the a.m. and p.m. peak hours at the intersection of Twin
Oaks Valley Road / SR-78 Eastbound Ramps under all analysis scenarios without and with the
proposed project. At the request of Caltrans, an Existing Plus Phase One Project scenario was also
included in this queuing analysis, which was not evaluated in the intersection level of service
analysis.
The purpose of the queuing analysis is to determine if the proposed project results in queuing
impacts to the freeway lanes on eastbound SR-78 where the Twin Oaks Valley Road off-ramp
diverges from the freeway mainline lanes. The SYNCHRO software program was utilized to conduct
the queuing analysis, which reports both 50th percentile (average) and 95th percentile (maximum)
queue lengths.
There are currently two lanes exiting the SR-78 freeway at the Twin Oaks Valley Road eastbound off-
ramp, which transition to three lanes approaching the intersection with Twin Oaks Valley Road. The
total length of the off-ramp from the freeway mainline lanes to Twin Oaks Valley Road is
approximately 780 feet. An auxiliary lane approximately 2,150 feet in length is currently provided
along eastbound SR-78 between the on-ramp at San Marcos Boulevard and the off-ramp at Twin
Oaks Valley Road.
There are currently three eastbound approach lanes at the intersection with Twin Oaks Valley Road:
one left-turn lane, one shared left-turn/through/right-turn lane, and one right-turn lane. The left-
turn lane is constructed as a turn bay and is approximately 300 feet in length. The two off-ramp
lanes transition to the center and right-turn intersection approach lanes, and have a total length of
approximately 780 feet.
All analysis scenarios assume the existing lane configuration at the eastbound intersection
approach, with the exception of the mitigated condition under Horizon Year 2030 conditions with
the project, which includes a total of four lanes at the eastbound approach of the intersection. The
recommended additional right-turn lane at the intersection is assumed to have a length of 300 feet
to be consistent with the existing lanes at the intersection approach.
The results of the queuing analysis at Twin Oaks Valley Road / SR-78 Eastbound Ramps under
existing plus project conditions are summarized in Table 38. The Year 2016 and Year 2020
cumulative conditions analysis results are summarized in Table 39. Table 40 presents the results of
the Horizon Year 2030 conditions analysis, without and with the recommended mitigation measure.
As shown in Tables 38 and 39, the reported and adjusted 95th percentile queue lengths are not
forecast to exceed the total length of the eastbound off-ramp lanes (780 feet) under existing, Year
2016 and Year 2020 cumulative conditions with the proposed project.
Heart of the City Specific Plan Amendment (Rancho Coronado) 117 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 38. Peak Hour Intersection Queuing Analysis Twin Oaks Valley Road / SR-78 Eastbound Ramps (Existing /
Existing Plus Project Conditions)
Ramp and Intersection Approach Lane
#
Lanes
Length
(feet)
AM Peak Hour PM Peak Hour
Volume
Per
Lane (1)
Reported
50%
Queue (2)
Reported
95%
Queue (2)
Adjusted
95%
Queue (3)
Volume
Per
Lane (1)
Reported
50%
Queue (2)
Reported
95%
Queue (2)
Adjusted
95%
Queue (3)
Existing Conditions
EB Left-Turn 1 300’ 355 287 371 300 254 212 283 NA (4)
EB Left-Turn/Through/Right-Turn (shared) 1 780’ 333 260 354 366 237 156 234 NA (4)
EB Right-Turn 1 780’ 330 221 307 366 235 147 221 NA (4)
Existing Plus Phase One Project Conditions
EB Left-Turn 1 300’ 355 286 371 300 257 216 288 NA (4)
EB Left-Turn/Through/Right-Turn (shared) 1 780’ 336 262 358 370 242 164 242 NA (4)
EB Right-Turn 1 780’ 332 224 311 370 237 152 226 NA (4)
Existing Plus Phase Two (Build-Out) Project Conditions
EB Left-Turn 1 300’ 355 270 369 300 263 222 293 NA (4)
EB Left-Turn/Through/Right-Turn (shared) 1 780’ 374 297 420 428 263 195 278 NA (4)
EB Right-Turn 1 780’ 375 254 367 428 261 175 253 NA (4)
Notes: (1)
Peak hour volume per lane is derived from the SYNCHRO calculation worksheets used in this queuing analysis. SYNCHRO includes the peak hour factor (PHF) in the vehicles
per hour per lane (vphpl) calculations (shown as “Lane Group Flow” in the SYNCHRO output worksheets). The PHF factors are included in the queuing analysis calculations but
are taken out to report the volume per lane calculations, this is to provide the “true” volume rather than a factored volume calculation. (2)
Queue lengths in SYNCHRO are expressed in feet. (3)
The 95th
percentile queue lengths in SYNCHRO were adjusted where queue lengths exceeded the length of the left turn lane (300 feet), which is constructed as a turn bay.
Since the center and right turn lanes extend for the full length of the off-ramp (780 feet), any reported left-turn lane queues exceeding 300 feet would spill back into the
center lane, which also allows left turn movements. The reported left-turn queue lengths beyond 300 feet were added to the center lane, and the queue lengths of the center
and right-turn lanes were averaged to reflect balanced queue lengths since the center lane allows both left and right turn movements. This adjustment provides more
conservative and accurate queue lengths for the three intersection approach lanes, and account for queues spilling back in the two off-ramp lanes upstream from the
intersection. (4)
NA = Not Applicable. Reported 95th
percentile queue lengths were not adjusted where the left-turn queue length is 300 feet or less.
Heart of the City Specific Plan Amendment (Rancho Coronado) 118 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 39. Peak Hour Intersection Queuing Analysis Twin Oaks Valley Road / SR-78 Eastbound Ramps (Year 2016 /
Year 2020 Cumulative Conditions)
Ramp and Intersection Approach Lane
#
Lanes
Length
(feet)
AM Peak Hour PM Peak Hour
Volume
Per
Lane (1)
Reported
50%
Queue (2)
Reported
95%
Queue (2)
Adjusted
95%
Queue (3)
Volume
Per
Lane (1)
Reported
50%
Queue (2)
Reported
95%
Queue (2)
Adjusted
95%
Queue (3)
Year 2016 Cumulative Conditions Without Project
EB Left-Turn 1 300’ 387 273 384 300 283 224 304 300
EB Left-Turn/Through/Right-Turn (shared) 1 780’ 423 327 472 472 291 217 310 295
EB Right-Turn 1 780’ 411 263 388 472 291 188 276 295
Year 2016 Cumulative Conditions With Project (Phase One)
EB Left-Turn 1 300’ 387 272 384 300 283 221 304 300
EB Left-Turn/Through/Right-Turn (shared) 1 780’ 425 329 480 478 303 228 328 305
EB Right-Turn 1 780’ 413 264 391 478 291 187 277 305
Year 2020 Cumulative Conditions Without Project
EB Left-Turn 1 300’ 387 258 372 300 283 212 304 300
EB Left-Turn/Through/Right-Turn (shared) 1 780’ 454 350 548 521 330 258 376 348
EB Right-Turn 1 780’ 444 281 422 521 324 210 316 348
Year 2020 Cumulative Conditions With Project (Phase Two Build-Out)
EB Left-Turn 1 300’ 387 254 366 300 283 204 304 300
EB Left-Turn/Through/Right-Turn (shared) 1 780’ 488 387 608 572 355 279 450 404
EB Right-Turn 1 780’ 480 314 470 572 351 228 354 404
Notes: (1)
Peak hour volume per lane is derived from the SYNCHRO calculation worksheets used in this queuing analysis. SYNCHRO includes the peak hour factor (PHF) in the vehicles
per hour per lane (vphpl) calculations (shown as “Lane Group Flow” in the SYNCHRO output worksheets). The PHF factors are included in the queuing analysis calculations but
are taken out to report the volume per lane calculations, this is to provide the “true” volume rather than a factored volume calculation. (2)
Queue lengths in SYNCHRO are expressed in feet. (3)
The 95th
percentile queue lengths in SYNCHRO were adjusted where queue lengths exceeded the length of the left turn lane (300 feet), which is constructed as a turn bay.
Since the center and right turn lanes extend for the full length of the off-ramp (780 feet), any reported left-turn lane queues exceeding 300 feet would spill back into the
center lane, which also allows left turn movements. The reported left-turn queue lengths beyond 300 feet were added to the center lane, and the queue lengths of the center
and right-turn lanes were averaged to reflect balanced queue lengths since the center lane allows both left and right turn movements. This adjustment provides more
conservative and accurate queue lengths for the three intersection approach lanes, and account for queues spilling back in the two off-ramp lanes upstream from the
intersection.
Heart of the City Specific Plan Amendment (Rancho Coronado) 119 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 40. Peak Hour Intersection Queuing Analysis Twin Oaks Valley Road / SR-78 Eastbound Ramps (Horizon Year 2030 Conditions)
Ramp and Intersection Approach Lane
#
Lanes
Length
(feet)
AM Peak Hour PM Peak Hour
Volume
Per
Lane (1)
Reported
50%
Queue (2)
Reported
95%
Queue (2)
Adjusted
95%
Queue (3)
Volume
Per
Lane (1)
Reported
50%
Queue (2)
Reported
95%
Queue (2)
Adjusted
95%
Queue (3)
Horizon Year 2030 Conditions Without Project
EB Left-Turn 1 300’ 564 467 715 300 384 298 443 300
EB Left-Turn/Through/Right-Turn (shared) 1 780’ 525 417 676 859 372 289 468 490
EB Right-Turn 1 780’ 521 388 627 859 362 238 369 490
Horizon Year 2030 With Project (Phase Two Build-Out)
EB Left-Turn 1 300’ 564 471 723 300 408 324 443 300
EB Left-Turn/Through/Right-Turn (shared) 1 780’ 558 502 749 940 384 309 468 490
EB Right-Turn 1 780’ 559 447 707 940 378 255 369 490
Horizon Year 2030 With Project (Phase Two Build-Out) - With Mitigation
EB Left-Turn 1 300’ 439 356 556 300 305 235 329 300
EB Left-Turn/Through/Right-Turn (shared) 1 780’ 431 353 595 641 300 246 356 305
EB Right-Turn 1 780’ 406 329 457 641 282 207 263 305
EB Right-Turn (Mitigation for Project Impact) 1 300' 406 329 457 300 282 207 263 300
Notes: (1)
Peak hour volume per lane is derived fromthe SYNCHRO calculation worksheets used in this queuing analysis. SYNCHRO includes the peak hour factor (PHF) in the vehicles per
hour per lane (vphpl) calculations (shown as “Lane Group Flow” in the SYNCHRO output worksheets). The PHF factors are included in the queuing analysis calculations but are
taken out to report the volume per lane calculations, this is to provide the “true” volume rather than a factored volume calculation. (2)
Queue lengths in SYNCHRO are expressed in feet. (3)
The 95th
percentile queue lengths in SYNCHRO were adjusted where queue lengths exceeded the length of the left turn lane (300 feet), which is constructed as a turn bay.
Since the center and right turn lanes extend for the full length of the off-ramp (780 feet), any reported left-turn lane queues exceeding 300 feet would spill back into the
center lane, which also allows left turn movements. The reported left-turn queue lengths beyond 300 feet were added to the center lane, and the queue lengths of the center
and right-turn lanes were averaged to reflect balanced queue lengths since the center lane allows both left and right turn movements. This adjustment provides more
conservative and accurate queue lengths for the three intersection approach lanes, and account for queues spilling back in the two off-ramp lanes upstream from the
intersection.
Note: Queue lengths exceeding total length of off-ramp lanes are indicated in bold.
Heart of the City Specific Plan Amendment (Rancho Coronado) 120 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 40 shows that under Horizon Year 2030 conditions without and with the project, the a.m. peak
hour 95th percentile queue lengths of the center and right-turn lanes are forecast to exceed the
total lengths of the two off-ramp lanes, based on the adjusted queue lengths. The adjusted 95th
percentile queue lengths in the two off-ramp lanes are forecast to spill back into the auxiliary lane
and one of the mainline freeway lanes. As shown in Table 40, the recommended mitigation
measure will reduce the adjusted 95th percentile queue length to less than the total length of the
off-ramp lanes. Therefore, the recommended additional right-turn lane will also mitigate the
queuing impacts to the freeway in addition to mitigating the identified significant impact at the
intersection with Twin Oaks Valley Road.
Caltrans Analysis Summary
The ILV methodology of intersection analysis indicated that the ramp intersections are forecast to
operate at Capacity without and with the project from Year 2016 through year 2030. To determine
significant impacts at the ramp intersections, the HCM methodology is used. As presented earlier in
this report, significant impacts were identified at the intersection of Twin Oaks Valley Road / SR-78
Eastbound Ramps under all analysis scenarios with the proposed project.
The results of the peak hour freeway segment analysis show that the addition of project-generated
traffic to freeway segments operating at deficient levels of service would not result in significant
impacts under any of the study scenarios since the forecast reduction in speed is less than 1.0 mph.
Speed and density calculations cannot be made when the freeway segment is operating at LOS F,
which occurs with the existing freeway capacity on SR-78. By 2030, all study freeway segments are
forecast to operate at LOS E or better during the peak hours.
The results of the ramp metering analysis show that under Horizon Year conditions, the addition of
project-related traffic to the Twin Oaks Valley Road / SR-78 Eastbound On-Ramp during the p.m.
peak hour is forecast to result in a ramp meter delay that exceeds the policy threshold of 15minutes.
The increase in ramp meter delay associated with project-related traffic is forecast to result in an
increase in delay that exceeds the significant impact threshold of 2 minutes according to the
SANTEC/ITE TIS Guidelines.
As previously discussed, the existing ramp meter flow rates were used for all future analysis
scenarios. This assumption provided a conservative analysis because there are planned capacity
improvements on eastbound SR-78 through the study area that would likely allow for adjustments in
the future ramp meter rate at the Twin Oaks Valley Road Eastbound On-Ramp.
The planned freeway improvements for eastbound SR-78 through the study area are listed below:
• One new auxiliary lane will be provided, extending from immediately upstream of the San
Marcos Boulevard On-Ramp and connecting with the existing auxiliary lane that is currently
provided from the San Marcos Boulevard eastbound on-ramp to the Twin Oaks Valley Road
eastbound off-ramp. 101
• A second eastbound auxiliary lane will be provided that will begin at the San Marcos Boulevard
eastbound on-ramp and will terminate at the Twin Oaks Valley Road eastbound off-ramp. The
first auxiliary lane will be extended east though the Twin Oaks Valley Road interchange and will
terminate at the Woodland Parkway/Barham Drive eastbound off-ramp.
Heart of the City Specific Plan Amendment (Rancho Coronado) 121 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
• The lengths of the San Marcos Boulevard and Twin Oaks Valley Road eastbound on-ramps would
be increased to provide longer acceleration and merging distances from the ramp meters to the
freeway ramp gore points.
• A new eastbound auxiliary lane will be provided from the reconfigured Barham Drive/Woodland
Parkway interchange that will extend east to connect with the existing auxiliary lane that
currently begins immediately east of the SPRINTER overcrossing.
The improvements listed above are planned to be completed prior to the year 2030 and are
included in the Horizon Year 2030 conditions analysis.
The existing ramp meter flow rate of 570 vehicles per hour during the p.m. peak period equates to
approximately 9.5 cycles per minute at the Twin Oaks Valley Road Eastbound On-Ramp. Based on
the existing p.m. ramp meter rate, the forecast ramp meter delay is 17 minutes under Horizon Year
2030 conditions with the proposed project. If the p.m. ramp meter flow rate were adjusted slightly
to 600 vehicles per hour, the forecast ramp meter delay under 2030 conditions with the project
would decrease to 13 minutes, which is equivalent to the forecast p.m. ramp meter delay without
the project. The adjustment to 600 vehicles per hour is equivalent to 10 cycles per minute, a
difference of only one-half cycle per minute.
This adjustment in the p.m. ramp meter rate should be feasible based on the expected improvement
in freeway operations when the planned improvements are completed. Therefore, it is reasonable
to expect that the planned improvements along eastbound SR-78 would reduce the identified ramp
meter impact to a level that is less than significant, and no mitigation measures would be required.
deficient ramp meter delay under Horizon Year 2030 conditions. Therefore, the project results in a
significant impact at the Twin Oaks Valley Road / SR-78 Eastbound On-Ramp and mitigation
measures are required (Impact TR-3). There are two options to reduce this impact to below a level
of significance:
MM-TR-3 One of the following options shall be implemented at the intersection of Twin Oaks
Valley Road / SR-78 EB On-Ramp:
• Adjusting the ramp meter rate to accommodate the increase in demand at
the on-ramp; or
• Converting the existing HOV lane to a third SOV lane on the on-ramp to
increase on-ramp capacity.
•
Implementation of mitigation measure MM-TR-3, which will be required as a condition of project
approval will reduce the deficient ramp meter delay under the Horizon Year 2030 conditions at the
Twin Oaks Valley Road / SR-78 Eastbound On-Ramp during the p.m. peak hour to below a level of
significance.
The results of the queuing analysis for the eastbound off-ramp at Twin Oaks Valley Road show that
the Horizon Year 2030 queuing impacts to the eastbound freeway lanes will be mitigated by the
recommended additional right-turn lane at the eastbound (off-ramp) intersection approach at Twin
Oaks Valley Road (MM-TR-1).
Heart of the City Specific Plan Amendment (Rancho Coronado) 122 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
c) Result in a change in air traffic patterns, including either an increase in traffic levels or a
change in location that results in substantial safety risks? No Impact
The project site is located approximately six miles east of McClellan-Palomar Airport. Given the type
of development proposed (residential and open space preservation), as well as the project’s
distance from the airport, the project will not result in a change in air traffic patterns. Therefore, no
impacts are identified for this issue area.
d) Substantially increase hazards due to a design feature (e.g., sharp curves or dangerous
intersections) or incompatible uses (e.g., farm equipment)? No Impact
The roadways designed for this project do not have any sharp curves, nor do they create dangerous
intersection. Two traffic circles to facilitate traffic flows are proposed along the Backbone Road and
another traffic circle is considered for the future intersection of Village Drive North/Carnation
Court/project road. Traffic circles would not be characterized as a design that would substantially
increase hazards or incompatible uses. Therefore, no impact is identified for this issue area.
e) Result in inadequate emergency access? Less Than Significant Impact
The project provides adequate emergency access. Street widths meet the requirements of the San
Marcos Fire Department and there are two ways into the residential community. Construction of the
proposed project will not result in the closure of any roads that would impede emergency access.
Therefore, impacts are less than significant.
f) Result in inadequate parking capacity? Less Than Significant Impact
The project is a new development and does not remove any existing parking on the project site or in
the project vicinity. Each residential unit will have either front-loaded or alley-loaded garage
parking. In addition to the garage parking for each unit, there will be 299 on-street parking spaces
spread across the residential development area. The future park and non-residential multi use
development will also be required to have adequate parking. Therefore, the project will not result in
inadequate parking capacity and impacts are less than significant.
g) Conflict with adopted policies, plans, or programs supporting alternative transportation (e.g.,
bus turnouts, bicycle racks)? No Impact
Existing and Future Bicycle and Pedestrian Access
Class II bike lanes are currently provided on both sides of Twin Oaks Valley Road through the project
study area and along the project frontage. Bike lanes will be provided on the proposed “Backbone
Road”, which will provide access to both Craven Road and Twin Oaks Valley Road from the proposed
project site. The “Backbone Road” will also provide bicycle access to the adjacent proposed school
from existing neighborhoods that access Santa Barbara Drive, thus providing a shorter, more direct
route to the school from those neighborhoods. There are currently bike lanes on both sides of the
street on North Village Drive, and the extension of North Village Drive to the “Backbone Road” will
include the extension of the bike lanes.
Pedestrian access to the proposed project site would be provided from Santa Barbara Drive
(existing), North Village Drive (existing), and South Village Drive (future). Along Twin Oaks Valley
Heart of the City Specific Plan Amendment (Rancho Coronado) 123 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Road north of North Village Drive, there is currently an 8-foot sidewalk on the west side of the
street. Between North Village Drive and South Village Drive, there is currently a narrow unpaved
footpath provided along the west side of Twin Oaks Valley Road, which is along the project frontage.
Phase Two of the proposed project will include construction of a sidewalk along the west side of
Twin Oaks Valley Road.
Sidewalks will be constructed along the extensions of Santa Barbara Drive and North Village Drive
under Phase One of the proposed project. Continuous pedestrian access will ultimately be provided
between Santa Barbara Drive and the Twin Oaks Valley Road / South Village Drive intersection when
the “Backbone Road” is completed under Phase Two. The “Backbone Road” will also provide
pedestrian access to the adjacent non-residential mixed use site from both the proposed project site
and the existing neighborhoods near Santa Barbara Drive.
In summary, the project will enhance bicycle and pedestrian transportation options in the project
area, therefore no impact is identified.
Existing and Future Transit Access
There is currently no transit service along Twin Oaks Valley Road south of Craven Road, and future
transit service is not anticipated to be provided within a reasonable walking distance of the
proposed project. The nearest transit stop is located on Craven Road near the intersection with
Rush Drive, which is located approximately between one-half and three-fourths of a mile from the
proposed project site. This transit stop serves Breeze Route 347, which provides transit service
between Palomar Community College and CSU San Marcos. The project does not propose any uses
that would conflict with existing transit options, therefore no impact is identified.
XVII. UTILITIES AND SERVICE SYSTEMS
A Water and Sewer Study was prepared for the project by Vallecitos Water District (2014). The
complete report is included as Appendix N of this document.
a) Exceed wastewater treatment requirements of the applicable Regional Water Quality Control
Board? Less than Significant Impact
The project will not exceed wastewater treatment requirement of the applicable Regional Water
Quality Control Board. Impacts are less than significant.
b) Require or result in the construction of new water or wastewater treatment facilities or
expansion of existing facilities, the construction of which would cause significant
environmental effects. Less than Significant Impact
Water Facilities Analysis
Water Distribution Infrastructure Analysis – The project is within the boundaries of the Vallecitos
Water District (VWD) for water service and is within the 920 Pressure Zone. Water service will be
connected to the existing 14-inch South Lake Pump Station inlet approximately 800 feet west of the
intersection of Twin Oaks Valley Road and Village Drive. The project includes the necessary utility
improvements to support the proposed development and includes approximately 15,360 linear feet
of water lines. An existing 14 inch Vallecitos Water District water main will be relocated. Water
Heart of the City Specific Plan Amendment (Rancho Coronado) 124 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
modeling prepared by VWD concluded that the project would not create any new distribution
system deficiencies under average day demand, maximum day demand, and peak hour demand
conditions. No system deficiencies were identified under maximum day plus fire flow demand
conditions. Therefore, the project will have a less than significant impact related to water
distribution infrastructure.
Water Storage Analysis – The VWD 2008 Master Plan assumed water demand on the site would be
268,550325,562 gallons per day (gpd). Under the proposed development, the project would have a
water demand of 269,884 253,745 gpd. This represents an increasea decrease of approximately
1,334 71,817 gpd (Table 41).
Table 41. Rancho Coronado Estimated Water Demand
Land Use Type
Area
(acres)
Number of
Residential Units
Duty Factor
(gpd/acre)
Water Demand
(gpd)
2008 Master Plan Land Use Demand
Residential
(.125 to 1.0 du/acre) 96.78 --- 600 58,068
Residential
(2-4 du/acre) 91.62 --- 1,800 164,916
Parks/Golf Courses 60.34 --- 1,700 102,578
TOTAL 248.74 325,562
Proposed Project
Residential
(4-8 du/acre) 50.95
346 single family
(high-efficiency) 2,500 127,375
Parks/Golf Courses 38.60 --- 1,700 65,620
Open Space 129.29 --- 200 25,858
Commercial
(Business Park) 22.24 --- 1,500 33,360
Right-of-Way 7.66 --- 200 1,532
TOTAL 248.74 --- --- 253,745
Heart of the City Specific Plan Amendment (Rancho Coronado) 125 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Table 41. Rancho Coronado Estimated Water Demand
Land Use Type
Area
(acres)
Number of
Residential Units
Duty Factor
(gpd/acre)
Water Demand
(gpd)
2008 Master Plan Land Use Demand
Residential
(0.05 – 0.25 du/acre) 83.6 --- 1,000 83,600
Residential
(1-2 du/acre) 14.9 --- 1,200 17,880
Residential
(2-4 du/acre) 63.3 --- 1,800 113,940
Industrial 39.0 --- 1,000 39,000
Recreational 2.5 --- 1,700 4,250
Open Space 49.4 --- 200 9,800
TOTAL 252.7 268,550
Proposed Project
Residential
(4-8 du/acre) 58.1
346 single family
(high-efficiency) 2,500 145,250
Non-Residential
Mixed Use
(Business Park/Retail)
22.24 --- 1,500 33,360
Parks 38.48 --- 1,700 65,416
Open Space 129.29 --- 200 25,858
TOTAL 248.01 --- --- 269,884
Note:
(1) CEQA analysis assumed 240,000 s.f. of development within the non-residential mixed use area with 90% being
business/office park and 10% being retail.
Potable water storage within VWD is sized for operational, emergency, and fire flow storage. Since
the project does not increase the water demand above what was projected for the project site in
the 2008 Master Plan, the storage requirement to serve the project has already been included in the
2008 Master Plan CIP infrastructure and no further storage upgrades are required. Therefore
impacts are less than significant.
This increase in water demand will result in increase of potable water storage demand capacity by
6,670 gallons. The project will pay Water Capital Facility Fees per VWD Ordinance No. 175. This
requirement is also noted in Table 2. These fees will be used by VWD to expand water storage
facilities, as needed, within their service area. VWD considers payment of the Water Capital Facility
Fees as mitigation for the increase in water storage demand. Therefore, impacts are less than
significant.
Water Pump Station Analysis - Pump stations are sized to supply minimum day flows while meeting
all pressure criteria within their service area. Since the proposed project is located in a pressure
zone that is not served by pumping, there are no pump station requirements for the project. Thus,
no impact is identified related to water pump stations.
Heart of the City Specific Plan Amendment (Rancho Coronado) 126 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Wastewater Facilities Analysis
The project site lies completely within VWD sewer shed 36C. A ten-inch sewer line exists to the east
of the project site within Twin Oaks Valley Road and an 8-inch sewer line exists north of the project
site at the intersection of Orchid Avenue and Santa Barbara Drive.
Currently, the project site is not within VWD’s sewer district boundaries and the entire project site
must be annexed to be eligible for sewer service. This is an intra-district annexation and does not
require Local Agency Formation Commission (LAFCO) approval or process.
Table 42. Rancho Coronado Estimated Wastewater Flows
Land Use Type
Area
(acres)
Number of
Residential Units
Duty Factor
(gpd/acre)
Wastewater Flow
(gpd)
2008 Master Plan Land Use Demand
Residential
(.125 to 1.0 du/acre) 96.78 --- 150 14,517
Residential
(2-4 du/acre) 91.62 --- 750 68,715
Parks/Golf Courses 60.34 --- 250 15,085
TOTAL 248.74 98,317
Proposed Project
Residential
(4-8 du/acre) 50.95
346 single family
(high-efficiency) 1,300 66,235
Parks/Golf Courses 38.60 --- 250 9,650
Open Space 129.29 --- 40 5,172
Commercial
(Business Park) 22.24 --- 1,200 26,688
Right-of-Way 7.66 --- 0 0
TOTAL 248.74 --- --- 107,745
VWD’s 2008 Maser Plan assumed a wastewater generation of 95,145 gpd for the project site. Under
the proposed project, the wastewater generation is anticipated to be 117,010 107,745 gpd. This
represents an increase of 21,865 9,428 gpd (Table 42).
Wastewater Collection System Analysis - Increased generation of wastewater from the project
would impact the sewer collection infrastructure in the direct vicinity of the project as well as the
downstream infrastructure to Lift Station No. 1 on San Marcos Boulevard. Modeling prepared by
VWD determined that the 8-inch collection pipe in Craven Road is projected to be undersized from
Santa Barbara Drive to approximately 575 feet south of Discovery Street. This would occur under
the ultimate buildout conditions, even without the proposed project’s increased flows. For ultimate
buildout, the VWD 2008 Master Plan identifies approximately 2,700 feet of 8-inch pipeline to be
replaced with 700 feet of 10-inch pipeline and 2,000 feet of 12-inch pipeline as part of CIP #24 for
construction between the years 2021 and 2025. This CIP is to be completed funded by development
without contribution from the VWD capacity fund. The additional wastewater flows from the project
do not result in any other new deficiencies under peak wet weather flows during ultimate build-out
conditions.
Heart of the City Specific Plan Amendment (Rancho Coronado) 127 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
The project will upsize this off-site segment of sewer line per the requirements of VWD. The upsizing
will be only to accommodate flows from the proposed project. This will ensure impacts are less than
significant.
Wastewater Life Station Analysis - Lift stations are sized for peak wet weather flow. Since the
project site is not located in a sewer shed that is served by a lift station (Lift Station No. 1 is a
stripping station and does not meet this definition) or requires a lift station, there are no lift station
upgrade requirements for the project. Thus no impact is identified.
Parallel Land Outfall Analysis - VWD’s existing outfall is approximately eight miles in length and
consists of four gravity pipeline sections and three siphon sections varying from 20 to 54 inches.
VWD maintains the entire pipeline from Lift Station No. 1 to the Encina Pollution Control Facility
(EWPCF).
VWD is currently considering two scenarios for increasing increased wastewater flows from planned
development within their service area. The first option is constructing a peak flow storage area near
Lift Station No. 1. The second option is to convey peak flows to the EWPCF through a parallel land
outfall.
The project will pay Wastewater Capital Facility Fees per VWD Ordinance No. 176 and Wastewater
Density Impact Fees per VWD Ordinance 177. This requirement is also noted in Table 2. These fees
will be used by VWD to help fund the parallel land outfall expansion. VWD considers payment of the
fees as mitigation for the increase in the need for land outfall capacity. Therefore, impacts are less
than significant.
Wastewater Treatment Facility Analysis - VWD uses two wastewater treatment facilities to treat
wastewater that is collected within its sewer service area: the MRF and the EWPCF. The project will
increase the wastewater flows from the project site by approximately 21,8659,428 gpd. VWD is
already projected to experience ultimate solids handling, liquids handling and ocean disposal
capacity deficiencies.
The project will pay Wastewater Capital Facility Fees per VWD Ordinance No. 176 and Wastewater
Density Impact Fees per VWD Ordinance 177. This requirement is also noted in Table 2. These fees
will be used by VWD to help fund the expansion and/or construction of wastewater treatment
facilities to handle increase wastewater quantities. VWD considers payment of the fees as
mitigation for the increase in treatment need. Therefore, impacts are less than significant.
c) Require or result in the construction of new storm water drainage facilities or expansion of
existing facilities, the construction of which could cause significant environmental effects?
Less than Significant Impact
The project proposes a comprehensive stormwater management plan that includes stormwater
improvements within the project boundary. This includes bio-retention features that will detain and
retain stormwater flows from the pads and roads. These features have been sized to accommodate
stormwater flows, as detailed in the WQIP (Appendix J) and the Hydrology report (Appendix I) for
the project.
Heart of the City Specific Plan Amendment (Rancho Coronado) 128 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
The project includes approximately 11,198 linear feet of storm drains. Construction of these
facilities is proposed within the development footprint for the project. An expansion of existing
facilities will not be required to serve the project. Therefore, impacts are less than significant.
d) Have sufficient water supplies available to serve the project from existing entitlements and
resources, or are new or expanded entitlements needed? Less than Significant Impact
The VWD 2008 Master Plan assumed water demand on the site would be 268,550 325,562 gallons
per day (gpd). Under the proposed development, the project would have a water demand of
269,884 253,745 gpd. This represents an increasea decrease of approximately 71,817 1,334 gpd
(Table 41). Since the project does not increase the water demand above what was projected for the
project site in the 2008 Master Plan, the storage requirement to serve the project has already been
included in the 2008 Master Plan CIP infrastructure and no further storage upgrades are required.
Therefore impacts are less than significant. The minor increase in water demand would not be
characterized as significant from a supply perspective and impacts would be less than significant,
e) Result in a determination by the wastewater treatment provider, which serves or may serve
the project that it has adequate capacity to serve the project’s projected demand in addition
to the provider’s existing commitments? Less than Significant Impact
As analyzed in Section XVII.b., due to changes in the type of development assumed for the project
site, the project will increase the demand for wastewater treatment as well as land outfall capacity.
As noted in Section XVII.b, the project will pay Wastewater Capital Facility Fees per VWD Ordinance
No. 176 and Wastewater Density Impact Fees per VWD Ordinance 177. This requirement is also
noted in Table 2. These fees will be used by VWD to help fund the expansion and/or construction of
wastewater treatment facilities to handle increase wastewater quantities and also the expansion of
land outfall facilities. VWD considers payment of the fees as mitigation for the increase in treatment
need. Therefore, impacts are less than significant.
f) Be served by a landfill with sufficient permitted capacity to accommodate the project’s solid
waste disposal needs? Less than Significant Impact
Solid waste service in the City is provided by a private franchise hauler, EDCO Waste and Recycling
(EDCO), which handles all residential, commercial and industrial collections within the City. Waste
collected is then hauled to the Palomar Transfer Station in Carlsbad where it is then transported to
the Sycamore Sanitary Landfill in Santee.
The Escondido Transfer Station accepts mixed municipal waste, green materials, and
construction/demolition materials. It has a daily capacity of 2,500 tons with a permitted capacity of
3,402 tons/day. The Sycamore Sanitary Landfill has a daily permitted capacity of 3,965 tons/day of
solid waste, with an anticipated closure date of 2031 (CalRecycle 2013).
CalRecycle provides solid waste generation rates for various types of land uses. Construction and
demolition debris would be generation by the project through removal of the existing industrial
buildings and parking pavement. Construction and demolition debris recycling is available through
EDCO.
Based upon typical industry generation rates, the project is expected to generate approximately
795 tons/year or 2.1 tons/day (see table below.) This does not consider any waste diversion through
Heart of the City Specific Plan Amendment (Rancho Coronado) 129 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
recycling. It is expected that 50 percent of this total volume will be diverted from the landfill
through recycling, thus the volume going to the landfill is expected to be 397.5 tons/year or
1.05 tons/day.
Land Use
Generation
Rate
Units/s.f.
Proposed
Total Volume
(tons/year)
Residential 0.44/tons/DU/year 346 units 219
Commercial 0.0024 tons/s.f./year 240,000 s.f. 576
Total 795(1)
Source: CalRecycle estimated solid waste generation rates (1)
This does not include any diversion through recycling
DU = dwelling unit
s.f. = square feet
Currently, approximately 2,380 tons of waste enter the Sycamore Canyon Landfill each day (City of
San Diego 2013). Therefore there is approximately 1,585 tons/day of capacity at the landfill. Thus,
the project’s contribution of 1.5 tons/day would be a less than significant impact.
g) Comply with federal, state, and local statutes and regulations related to solid waste? No
Impact
The project will comply with all federal. State and local statutes and regulations related to solid
waste, including proper handling of construction and demolition debris. Thus no impact is identified
for this issue area.
Heart of the City Specific Plan Amendment (Rancho Coronado) 130 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
V. MANDATORY FINDINGS OF SIGNIFICANCE
The following are Mandatory Findings of Significance in accordance with Section 15065 of the CEQA
Guidelines.
a) Does the project have the potential to degrade the quality of the environment, substantially
reduce the habitat of a fish or wildlife species, cause a fish or wildlife population to drop below
self-sustaining levels, threaten to eliminate a plant or animal community, reduce the number or
restrict the range of a rare or endangered plant or animal or eliminate important examples of the
major periods of California history or prehistory? Less Than Significant Impact With Mitigation
Incorporated
Potential impacts to biological resources were analyzed in the document (Section 3.4). A biological
resources report was prepared for the project by HELIX (2014). Based upon the requirements of the
existing Habitat Loss Permit for the project site, mitigation measures MM-BIO-A through MM-BIO-G
are included for the project. Potential direct and indirect impacts to sensitive species will be
mitigated through the implementation of mitigation measures which will be required as a condition
of project approval (MM-BIO-1 through MM-BIO-4). These measures include avoidance during
nesting season, preconstruction surveys, and measures to reduce indirect impacts. These measures
also require habitat conservation, enhancement and creation. The project will implement a riparian
restoration plan (MM-BIO-1B) to mitigate for impacts to riparian habitat and jurisdictional wetlands
and waters. Preserved areas would be outside the 150-foot fuel modification buffer. The project will
also be required to secure permits from the regulatory agencies (USACE, CDFW and RWQCB) for
impact to jurisdictional waters and wetlands. Impact to biological resources will be mitigated to
below a level of significance.
Cultural resources were analyzed in Section 3.5 of this document. A cultural resources report was
prepared for the project by ASM (2013). The cultural resources records search and site visit did not
identify any cultural resources on the site. The cultural resources report did recommend monitoring
during grading in the event that unidentified cultural resources are encountered during project
grading. Implementation of mitigation measures (MM-CR-1 through MM-CR-8) will be required as a
condition of project approval and will this potential impact to below a level of significance.
Monitoring will reduce the potential for impact to eliminate important examples of the major
periods of California history or prehistory to below a level of significance.
Therefore, this project has been determined not to meet this Mandatory Finding of Significance and
impacts are less than significant with the incorporation of mitigation.
b) Does the project have impacts that are individually limited, but cumulatively considerable?
("Cumulatively considerable" means that the incremental effects of a project are considerable
when viewed in connection with the effects of past projects, the effects of other current projects,
and the effects of probable future projects.) Less Than Significant Impact With Mitigation
Incorporated
Cumulative impacts related to traffic, air quality and noise were analyzed in this CEQA document.
Based upon the analysis, the project will not have any cumulative impact related to air quality and
noise. The project will contribute to a cumulative traffic impact in the Horizon Year 2030 time
Heart of the City Specific Plan Amendment (Rancho Coronado) 131 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
frames. Mitigation measures MM-TR-1 and, MM-TR-2 and MM-TR-3 will reduce the impact to below
a level of significance. The project will be required to pay a fair share for improvements to reduce
the impacts to below a level of significance.
All other impacts were site-specific (e.g., cultural resources and hazards/hazardous materials) and
will not result in a significant cumulative impact. Therefore, this project has been determined not to
meet this Mandatory Finding of Significance and impacts are less than significant with the
incorporation of mitigation.
c) Does the project have environmental effects, which will cause substantial adverse effects on
human beings, either directly or indirectly? Less Than Significant Impact With Mitigation
Incorporated
In the evaluation of environmental impacts in this Initial Study, the potential for adverse direct or
indirect impacts to human beings were considered in the response to certain questions in
Sections I. Aesthetics, III. Air Quality, VI. Geology and Soils, VII. Hazards and Hazardous Materials,
VIII. Hydrology and Water Quality, XII. Noise, XIII. Population and Housing, and XVI. Transportation
and Traffic. As a result of this evaluation, there is no substantial evidence that there are adverse
effects on human beings associated with this project.
The Aesthetics analysis concluded that the project would result in a visual change to the project site
but that the change would be less than significant due to the incorporation of grading, landscape
and architectural design requirements identified in the Residential Design Guidelines and the
Specific Plan.
The Air Quality analysis concluded that emissions associated with project construction and
operation would be less than significant. The project will implement dust control measures during
construction and also use low-VOC coatings as required by SDAPCD Rule 67.0. These requirements
are included as design features.
The Geology and Soils analysis concluded that the project would have a less than significant impact.
Recommendations identified in the geotechnical report prepared for the project would be
implemented and these requirements were identified in summary of project design features
(Table 2).
The Hazards and Hazardous materials analysis concluded that impacts would be less than significant,
including hazards related to wildland fire. As a condition of project approval, the project will be
required to implement a fire protection plan (MM-HAZ-1). The fire protection plan will be subject to
review and approval by the Fire Marshal.
The Hydrology/Water Quality section determined that impacts would be less than significant. The
design of the project, which includes 2.51 acres of bio-retention features to ensure post-condition
runoff is the same amount and rate as pre-condition runoff. The project also includes self-treating
areas (water quality lots). A comprehensive Water Quality Improvement Plan (Appendix I) to
address potential water quality pollutants that would be generated by the project by Fuscoe
Engineering (2013).
Heart of the City Specific Plan Amendment (Rancho Coronado) 132 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
The Noise section addressed both construction related noise (including blasting and rock crushing)
as well as operational noise. Mitigation measure MM-N-4 will be implemented to reduce potential
noise impacts associated with proposed rock crushing To minimize noise onsite from traffic, noise
barriers ranging from five to six feet will be required for the future homes on North Village Drive and
barriers ranging from six to ten feet will be required for rear yard areas that are adjacent to Twin
Oaks Valley Road (MM-N-1). Additionally, noise measurements for interior second story areas will
also be required (MM-N-2) and implementation of architectural treatments would be required if
interior noise levels are anticipated to be elevated. Finally, if outdoor usable areas are incorporated
into the future non-residential mixed use area, the design shall consider shielding and setback to
meet required noise levels (MM-N-3). Implementation of these noise mitigation measures, which
will be required as condition of project approval would reduce impacts to below a level of
significance.
The Population and Housing section growth inducement and displacement of people and housing.
Impacts were determined to be less than significant.
Finally, the Transportation and Traffic section concluded that the project will contribute to a
cumulative traffic impact in the Horizon Year 2030 Conditions time frame. Mitigation measures
MM-TR-1 and, MM-TR-2 and MM-TR-3 will reduce the impact to below a level of significance. The
project will be required to pay a fair share for improvements to reduce the impacts to below a level
of significance.
In summary, all impacts in these environmental issue areas are less than significant or mitigated to
below a level of significance. Therefore, this project has been determined not to meet this
Mandatory Finding of Significance and impacts are less than significant with the incorporation of
mitigation.
Heart of the City Specific Plan Amendment (Rancho Coronado) 133 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
VI. PERSONS AND ORGANIZATIONS CONSULTED
This section identifies those persons who prepared or contributed to preparation of this document. This
section is prepared in accordance with Section 15129 of the CEQA Guidelines.
A. CITY OF SAN MARCOS
Jerry Backoff, Planning Director
Garth Koller, Project Planner
Peter Kuey, Principal Civil Engineer
Susan Vandrew Rodriguez, Associate Planner
Matthew Ernau, Fire Division Chief/Fire Marshal
B. CONSULTANTS
CEQA Documentation
Sophia Mitchell & Associates
Sophia Habl Mitchell, LEED AP
Air Quality
Scientified Resourcs Associated
Valorie Thompson, Principal
Cultural Resources
ASM Affiliates
Shelby Castells, M.A., RPA
Nicholas Hanten, B.S.
Sinéad Ní Ghabhláin, Ph.D., RPA
Noise
LdN Consulting
Jeremy Louden, Principal
Traffic
RBF Consulting
David Mizell, Traffic Engineer
Heart of the City Specific Plan Amendment (Rancho Coronado) 134 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
VIII. REFERENCES
ASM Affiliates. 2013. Cultural and Historical Resources Survey Report for the Rancho Coronado Specific
Plan Project, City of San Marcos, San Diego County, California. November.
CalRecycle. 2013. Solid Waste Information System – Escondido Resource Recovery.
http://www.calrecycle.ca.gov/SWFacilities/Directory/37-AA-0906/Detail/ Viewed November
18, 2013.
CalRecycle. 2013. Solid Waste Information System – Sycamore Sanitary Landfill.
http://www.calrecycle.ca.gov/SWFacilities/Directory/37-AA-0023/Detail/ Viewed November 18,
2013.
California Department of Toxic Substance Control. Envirostor Database.
http://www.envirostor.dtsc.ca.gov/ Viewed January 23, 2014
Chang Consultants. 2007. Breach Study for South Lake and Development of Inundation Map for
Downstream Channel in the City of San Marcos. September.
City of San Marcos Fire Department. 2013. Letter to Sophia Habl Mitchell regarding fire protection
services from Fire Marshal Matthew Ernau. November 18.
County of San Diego Sheriff’s Department. 2012. E-mail correspondence from Corporal Malcolm Horst to
Susan Vandrew Rodriguez. September 20, 2012.
County of San Diego Sheriff’s Department. 2013. E-mail correspondence from Corporal Malcolm Horst to
Sophia Habl Mitchell. December 3, 2013.
Fusco Engineering. 2013. Preliminary Water Quality Improvement Plan Sheets. Rancho Coronado South.
December 5.
Geosyntec. 2013a. Letter report address to Craig Burnett at County of San Diego, Department of
Environmental Health Site Assessment and Mitigation Program. “Summary of Results, Additional
Soil Characterization Lehigh Hanson Property, San Marcos, California.” June 4.
Geosyntec. 2013b. Native Background Arsenic Summary. Former Hanson Aggregate San Marcos Plant,
San Marcos, California.
Helix Environmental. 2014. Rancho Coronado Biological Technical Report. January 20.
LdN Consulting. 2014. Noise Assessment Rancho Coronado Specific Plan. January 28.
RBF Consulting. 2014. Hanson Rancho Coronado Traffic Impact Analysis Report. January 30.
San Marcos Unified School District (via Bowie Arneson, Wiles & Giannone). 2012. Letter from Alexander
Bowie to Sophia Habl Mitchell. August 31.
Heart of the City Specific Plan Amendment (Rancho Coronado) 135 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
Scientific Resources Associates. 2014a. Air Report for the Rancho Coronado Specific Plan. January 29.
Scientific Resources Associates. 2014b. Global Climate Change Assessment for the Rancho Coronado
Specific Plan. January 29.
SCS Engineers. 2012. Phase I Environmental Site Assessment. Rancho Coronado Villages Project South
Twin Oaks Valley Road and Village Drive. January 30.
Vallecitos Water District. 2014. Rancho Coronado Villages Water and Sewer Study. February 27.
Heart of the City Specific Plan Amendment (Rancho Coronado) 136 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
IX. MITIGATED NEGATIVE DECLARATION
City of San Marcos
The following Mitigated Negative Declaration is being circulated for public review in accordance with
the California Environmental Quality Act Section 21091 and 21092 of the Public Resources Code.
Public Review Period: February 5, 2014 to March 7, 2014
Project Name: Heart of the City Specific Plan Amendment (Rancho Coronado)
Project Applicant: Lehigh Hanson West Region, PO BOX 639069, San Diego, CA 92613-9069
Project Location: The 248-acres project site is located within the southwestern portion of the Heart
of the City Specific Plan. The project site property is bounded by Twin Oaks Valley Road on the east,
the Discovery Hills residential community on the north, and undeveloped land on the west and
south in the Barham/Discovery Hills neighborhood. The project site coincides with the former
Hanson mining site. The eastern and northern portions of the former Hanson mining site are
disturbed from past aggregate mining activities and the remainder of the site is vegetated and
undeveloped. The project is proposed in areas that are disturbed from previous mining.
Project Description: The project proposes a Specific Plan amendment to the Heart of the City
Specific Plan. The project would develop 346 residential units, 22.24 acres of non-residential mixed
use (business park), approximately 38 acres of active park and the necessary infrastructure to
support the proposed development. The project also preserves 129.29 acres of open space and
includes a biological mitigation area. Discretionary actions for the project include approval of:
Specific Plan Amendment, and Tentative Subdivision Map.
Heart of the City Specific Plan Amendment (Rancho Coronado) 137 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
X. FINDINGS
This is to advise that the City of San Marcos, acting as the lead agency, has conducted an Initial Study
to determine if the project may have a significant effect on the environmental and is proposing this
Mitigated Negative Declaration based upon the following findings:
� The Initial Study shows that there is no substantial evidence that the project may have a
significant effect on the environment and a NEGATIVE DECLARATION will be prepared.
� The Initial Study identifies potentially significant effects but:
(1) Proposals made or agreed to by the applicant before this proposed Mitigated Negative
Declaration was released for public review would avoid the effects or mitigate the
effects to a point where clearly no significant effects would occur.
(2) There is no substantial evidence before the agency that the project may have a
significant effect on the environment.
(3) Mitigation measures are required to ensure all potentially significant impacts are
reduced to levels of insignificance. Mitigation proposed for the project includes:
Biological Resources Mitigation Measures
The following project design measures shall be carried forward from the HLP conditions to minimize
impacts to biological resources and are identified as mitigation measures for the project.
Implementation of these mitigation measures will be required as a condition of project approval.
MM-BIO-A The clearing and grubbing of sensitive habitats shall occur outside of the bird
breeding season (February 15 to August 31), unless a qualified biologist
demonstrates to the satisfaction of the City and the Wildlife Agencies that all
nesting is complete. The qualified biologist would need to be federally permitted
for coastal California gnatcatcher if the habitat being cleared has potential to
support these species.
MM-BIO-B Temporary perimeter fencing shall be installed to separate the proposed
development and the fuel management zones from any CSS areas to the preserved
under the HLP. The removal of temporary fencing is only to occur after all clearing
and construction has been completed.
MM-BIO-C Lots adjacent to biological open space will have permanent fencing and no gates
between the development and the open space; (a) landscaping will be restricted to
native and/or non-invasive plant species; and (b) Best Management Practices
(BMPs) during construction in accordance with Nation Pollutant Discharge
Elimination Systems General Construction Permit requirements will be
implemented.
Heart of the City Specific Plan Amendment (Rancho Coronado) 138 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
MM-BIO-D A biological monitor will be on-site when habitat is being cleared, and/or
construction activities are occurring within 100 feet of a Biological Open Space
Easement boundary. Permanent signs must be placed every 100 feet along the
fence bordering the preserve. The signs must be corrosion resistant, no less than
three feet above the ground surface, have minimum dimensions of 6” x 9”, and
must state the following:
Sensitive Environmental Resources
Disturbance Beyond this point is Restricted
By Easement
Information:
Contact (Name of Conservancy)
MM-BIO-E A conservation easement shall be placed over all on-site mitigation. Additionally,
the applicant shall insure that the biological open space is deeded to a nature
conservancy acceptable to the planning Division Director for maintenance and
monitoring purposes.
MM-BIO-F Manufactured slopes will be revegetated with appropriate native species in
consultation with the Wildlife Agencies. The landscape plan and construction
documents will be approved by the City Engineer, Planning Director, and Fire
Marshal prior to issuance of building permits.
MM-BIO-G Any lands providing mitigation/preservation for the project shall be held in
perpetuity in accordance with a habitat management plan to be approved by the
City and the Wildlife Agencies.
MM-BIO-1A Impacts to 0.23 acre southern riparian forest, 0.15 acre riparian woodland, 1.43
acres southern willow scrub, 0.90 acre freshwater marsh, 0.33 acre mule fat scrub,
and 0.09 SWS/FWM habitat will be mitigated at a 3:1 ratio. Impacts to 0.85 acres
disturbed wetland will be mitigated at a 2:1 ratio. Impact to 0.02 acre streambed
will be mitigated at a 1:1 ratio as detailed in Table 7a for a total of 8.89 acres of
mitigation. Mitigation includes a combination of onsite and offsite creation and
enhancement with 6.47 acres of creation and 0.30 acres of enhancement occurring
onsite and 1.07 1.27 acres creation mitigation credit equivalents and 1.05 acres
enhancement credits at the North County Habitat Bank (NCHB).
MM-BIO-1B The preparation of a riparian restoration plan will be required as a condition of the
mitigation for impacts to riparian vegetation communities. The plan will be require
review and approval by the City and include the following.
• All final specifications and topographic-based grading, planting, and
irrigation plans (0.5-foot contours and typical cross-sections) for the
creation/restoration sites. All wetland mitigation areas shall be graded to
the same elevation as adjacent existing jurisdictional wetlands areas, and/or
to within 1 foot of the groundwater table, and shall be left in a rough grade
state with micro topographic relief (including channels for wetlands) that
mimics natural topography, as directed by the City and Resource Agencies.
Heart of the City Specific Plan Amendment (Rancho Coronado) 139 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
All plantings shall be installed in a way that mimics natural plant
distribution, and not in rows;
• Planting palettes (plant species, size, and number/acre) and seed mix (plant
species and pounds/acre). Unless otherwise approved by the City and
Resource Agencies, only locally native species (no cultivars) obtained from
as close to the project area as possible shall be used. The source and proof
of local nativeness of all plant material and seed shall be provided;
• Container plant survival shall be 80 percent of the initial plantings for the
first year;
• A final implementation schedule that indicates when all riparian/wetland
impacts, as well as riparian/wetland creation/restoration grading, planting,
and irrigation, will begin and end. Necessary site preparation and planting
shall be completed during the concurrent or next planting season (i.e., late
fall to early spring). Any temporal loss of habitat caused by delays in
riparian/wetland habitat creation/restoration shall be offset through like
habitat creation/restoration at a 0.5:1 ratio for every 6 months of delay
(i.e., 1:1 for 12 months delay, 1.5:1 for 18 months delay, etc.). In the event
that the project applicant is wholly or partly prevented from performing
obligations under the final plans (causing temporal losses due to delays)
because of unforeseeable circumstances or causes beyond the reasonable
control, and without the fault of negligence of the project applicant,
including but not limited to natural disasters (e.g., earthquakes, etc.), labor
disputes, sudden actions of the elements (e.g., further landslide activity), or
actions or inaction by federal or state agencies, or other governments, the
project applicant will be excused by such unforeseeable cause(s);
• Five years of success criteria for wetland/riparian creation/restoration
areas, including: separate percent cover criteria for herbaceous understory,
shrub midstory, and tree overstory, and a total percent absolute cover for
all 3 layers at the end of 5 years; evidence of natural recruitment of multiple
species for all habitat types; 0 percent coverage for Cal-IPC’s “Invasive Plant
Inventory” species, and no more than 10 percent coverage for other
exotic/weed species;
• A minimum of 5 years of maintenance and monitoring of riparian/wetland
creation/restoration areas, unless success criteria are met earlier and all
artificial water supply has been off for at least 2 years
• A qualitative and quantitative vegetation monitoring plan with a map of
proposed sampling locations. Photo points shall be used for qualitative
monitoring and stratified-random sampling shall be used for all quantitative
monitoring;
• Contingency measures in the event of creation/restoration failure;
• Annual mitigation maintenance and monitoring reports shall be submitted
to the City and Resource Agencies no later than December 1 of each year;
Heart of the City Specific Plan Amendment (Rancho Coronado) 140 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
• A wetland delineation shall be done to confirm that USACE and CDFW
jurisdictional wetlands have been successfully created/restored prior to
final approval of creation/restoration sites.
MM-BIO-2 Potential direct impacts to bird species covered under the MBTA will be mitigated
by restricting brushing and grading to outside of the breeding season of most bird
species (general breeding season is February 15 to August 31). Grubbing, grading,
or clearing during the breeding season of MBTA covered species could occur if it is
determined via a pre-construction survey that no nesting birds (or birds displaying
breeding or nesting behavior) are present immediately prior to grubbing, grading, or
clearing and will require approval of the City that no breeding or nesting avian
species are present in the vicinity of the grubbing, grading, or clearing. The City
shall be notified of any sensitive bird species identified during the pre-construction
surveys.
MM-BIO-3 To reduce edge effects, on-site human activity, and potential impacts related to the
introduction of exotic and domestic animals, the biological open space lots shall be
actively managed and monitored. The required habitat management plan (as
detailed in MM-BIO-1B) shall ensure that access be restricted to developed areas.
Permanent fencing shall be provided for all backyards abutting proposed project
open space. In addition, preserved habitat shall be posted with signs precluding
access due to habitat sensitivity and prohibiting dumping. Residents shall be
educated in access restrictions, control of domestic animals, prevention of irrigation
runoff, and sensitivity of habitats on site.
MM-BIO-4 If project grading (other than clearing and grubbing of sensitive habitats) is
necessary and adjacent to preserved on-site habitat during the bird breeding season
(February 15 to August 31), a qualified biologist shall conduct pre-construction
surveys in the adjacent habitat for the coastal California gnatcatcher\ and nesting
raptors. The survey shall begin not more than three days prior to the beginning of
grading activities. The Wildlife Agencies shall be notified if the gnatcatcher is
observed nesting within 300 feet of proposed grading or if raptors are observed
nesting within 500 feet of proposed grading activities. No activities which would
result in noise levels exceeding 60 dBA hourly Leq within this buffer shall be allowed.
If grading activities are not initiated prior to the breeding season, and any of these
species are present, and noise levels exceed this threshold, noise barriers shall be
erected to reduce noise impacts to occupied habitat to below 60 dBA hourly Leq
and/or the activities shall be suspended. Impacts resulting from noise for non-listed
species other than raptors are not considered significant, and mitigation is not
warranted.
Cultural Resources Mitigation Measures
MM-CR-1 An archeological monitor and a Luiseño Native American monitor shall be present
during the all earth moving and grading activities to assure that any potential
cultural resources, including tribal, found during project grading be protected.
Heart of the City Specific Plan Amendment (Rancho Coronado) 141 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
MM CR-2 Prior to beginning project construction, the Project Applicant shall retain a San
Diego County qualified archaeological monitor to monitor all ground-disturbing
activities in an effort to identify any unknown archaeological resources. Any newly
discovered cultural resource deposits shall be subject to cultural resources
evaluation, which shall include archaeological documentation, analysis and report
generation.
MM-CR-3 At least 30 days prior to beginning project construction, the Project Applicant shall
enter into a Cultural Resource Treatment and Monitoring Agreement (also known as
a pre-excavation agreement) with contact a Luiseño Tribe. the Rincon Tribe to notify
the Tribe of grading, excavation and the monitoring program and to develop a
Cultural Resources Treatment and Monitoring Agreement. The Agreement shall
address the treatment of known cultural resources, the designation, responsibilities,
and participation of professional Native American Tribal monitors during grading,
excavation and ground disturbing activities; project grading and development
scheduling; terms of compensation for the monitors; and treatment and final
disposition of any cultural resources, sacred sites, and human remains discovered
on site.
MM-CR-4 Prior to beginning project construction, the Project Archaeologist shall file a pre-
grading report with the City to document the proposed methodology for grading
activity observation, which will be determined in consultation with the contracted
Luiseño Tribe referenced in MM-CR-3. the Rincon Tribe. Said methodology shall
include the requirement for a qualified archaeological monitor to be present and to
have the authority to stop and redirect grading activities. In accordance with the
agreement required in MM-CR-3, the archaeological monitor’s authority to stop and
redirect grading will be exercised in consultation the Luiseño Native American
monitor with the Rincon Tribe in order to evaluate the significance of any
archaeological resources discovered on the property. Tribal and archaeological
monitors shall be allowed to monitor all grading, excavation, and groundbreaking
activities, and shall also have the authority to stop and redirect grading activities.
MM-CR-5 The landowner shall relinquish ownership of all cultural resources collected during
the grading monitoring program and from any previous archaeological studies or
excavations on the project site to the appropriate Tribe for proper treatment and
disposition per the Cultural Resources Treatment and Monitoring Agreement
referenced in MM-CR-3., including sacred items, burial goods, and all archaeological
artifacts that are found on the project area to the appropriate Tribe for proper
treatment and disposition. All cultural materials that are deemed by the Tribe to be
associated with burial and/or funerary goods will be repatriated to the Most Likely
Descendant as determined by the Native American Heritage Commission per
California Public Resources Code Section 5097.98.
In the event that curation of cultural resources is required, curation shall be
conducted by an approved facility and the curation shalll be guided by California
State Historic Resource Commissions Guidelines for the Curation of Archaeological
Collections. The City of San Marcos shall provide the developer final curation
Heart of the City Specific Plan Amendment (Rancho Coronado) 142 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
language and guidance on the project grading plans prior to issuance of the grading
permit, if applicable, during project construction.
collected during the grading monitoring program and from any previous
archaeological studies or excavations on the project site, with the exception of
sacred items, burial goods, and human remains which will be addressed in the
Treatment Agreement required in MM-CR-3, shall be tribally curated according to
the current professional repository standards by the Rincon Tribe. The collections
and associated records shall be transferred, including title, to the Rincon Tribe.
MM-CR-6 All sacred sites, should they be encountered within the project area, shall be
avoided and preserved as the preferred mitigation, if feasible.
MM-CR-7 If human remains are encountered, California Health and Safety Code Section
7050.5 states that no further disturbance shall occur until the San Diego County
Coroner has made the necessary findings as to origin. Further, pursuant to California
Public Resources Code Section 5097.98(b) remains shall be left in place and free
from disturbance until a final decision as to the treatment and disposition has been
made. Suspected Native American remains shall be examined in the field and kept in
a secure location at the site If the San Diego County Coroner determines the
remains to be Native American, the Native American Heritage Commission (NAHC)
must be contacted within 24 hours. The NAHC must them immediately notify the
“most likely descendant(s)” of receiving notification of the discovery. The most likely
descendants(s) shall then make recommendations within 48 hours, and engage in
consultation concerning treatment of remains as provided in Public Resources Code
5097.98 and the Treatment Agreement described in MM-CR-3.,
MM-CR-8 If inadvertent discoveries of subsurface archaeological/cultural resources are
discovered during grading, the Developer, the project archaeologist, and the
Luiseño Tribe under agreement with the landowner described in MM-CR-3 shall
assess the significance of such resources and shall meet and confer regarding the
mitigation for such resources. Pursuant to California Public Resources Code Section
21083.2(b) avoidance is the preferred method of preservation for archaeological
resources. If the Developer, the project archaeologist and the Tribe cannot agree on
the significance of mitigation for such resources, these issues will be presented to
the Planning Director for decision. The Planning Director shall make a determination
based upon the provisions of the California Environmental Quality Act with respect
to archaeological resources and shall take into account the religious beliefs,
customs, and practices of the Tribe. Notwithstanding any other rights available
under law, the decision of the Planning Director shall be appealable to the Planning
Commission and/or City Council.
Hazards/Hazardous Materials Mitigation Measures
MM-HAZ-1 Prior to grading activities, the project applicant shall prepare and implement a soils
management plan that addresses handling of soils containing naturally-occurring
arsenic during grading. The management plan shall be submitted to the City
Engineer for review and approval prior to the issuance of a grading permit.
Heart of the City Specific Plan Amendment (Rancho Coronado) 143 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
MM-HAZ-2 Prior to issuance of building permits, a fire protection plan shall be prepared for the
project and submitted to the Planning Director and Fire Marshal for review and
approval. The fire protection plan shall include fire fuel clearing and fire fuel
management zones to provide a minimum 150-foot buffer between proposed
structures and natural habitat. The fire protection plan shall identify the responsible
parties for the ongoing fire fuel maintenance and the mechanism to ensure
compliance with fire clearing requirements. Implementation of the fire protection
plan shall be required prior project occupancy.
Noise Mitigation Measures
MM-N-1 Sound barriers ranging from five to ten feet shall be constructed to reduce future
onsite noise levels to be consistent with the Noise Element of the San Marcos
General Plan (60 dBA CNEL for single family and 65 dBA for multifamily). Locations
and heights of the proposed barriers are presented in Figure 7, Noise Mitigation
Measures. Barriers could include berms, wall, glass or a combination of these to
meet the required noise attenuation.
MM-N-2 A final noise assessment shall be prepared prior to the issuance of the first building
permit. This final report would identify the interior noise requirements based upon
architectural and building plans to meet the City’s established interior noise limit of
45 dBA CNEL.
MM-N-3 If outdoor usable areas are proposed in the non-residential mixed use areas of the
project, the design shall consider shielding form the buildings, increased setbacks
from the roadways or conduct a site specific noise study to determine compliance.
An interior noise assessment is required to mitigate the exterior noise levels to an
interior level of 50 dBA CNEL. This report should be conducted prior to the issuance
of building permits and would finalize the noise requirements based upon actual
building design specifications.
MM-N-4 If rock crushing is proposed, upon starting of crushing operations, noise
measurements of the rock crushing facility shall be required to ensure compliance
with the City’s thresholds. If noise levels are found to be above the established
thresholds of 60 dBA at any existing single family residential use, 65 dBA for any
multifamily use or 70 dBA at a commercial use then additional mitigation in the
form of berms or temporary walls will need to be incorporated into the rock crusher
design to reduce the noise levels to below the City’s thresholds.
Traffic Mitigation Measures
MM-TR-1 The project applicant shall make a fair share contribution towards the following
improvements at the Twin Oaks Valley Road/SR-78 Eastbound Ramps:
• Construct an additional dedicated right-turn lane at eastbound (off-ramp)
approach of intersection.
Heart of the City Specific Plan Amendment (Rancho Coronado) 144 City of San Marcos
Draft Initial Study/Mitigated Negative Declaration March 2014
• Restripe eastbound approach to include one left-turn lane, one shared left-
turn/through/right-turn lane, and two right-turn lanes.
MM-TR-2 The project applicant shall make a fair share contribution towards the widening of the
northbound approach of the Twin Oaks Valley Road/Discover Street-Barham Drive
intersection to construct a dedicated right-turn lane.
MM-TR-3 One of the following options shall be implemented at the intersection of Twin Oaks
Valley Road / SR-78 EB On-Ramp:
• Adjusting the ramp meter rate to accommodate the increase in demand at the
on-ramp; or
• Converting the existing HOV lane to a third SOV lane on the on-ramp to increase
on-ramp capacity.
A MITIGATED NEGATIVE DECLARATION will be prepared.
If adopted, the Mitigated Negative Declaration means that an Environmental Impact Report will not be
required. Reasons to support this finding are included in the attached Initial Study. The project file and
all related documents are available for review at the City of San Marcos, 1 Civic Center Drive, San
Marcos, CA 92069.
NOTICE
The public is invited to comment on the proposed Mitigated Negative Declaration during the review
period.
Date of Determination: March 19, 2014