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Table of Contents
Page
STANDARD DREDGE AND FILL APPLICATION FORM ................................... 1
ATTACHMENT A ..................................................................................... 5
PROJECT DESCRIPTION .......................................................................... 5 Existing Bridge ........................................................................... 5 Purpose and Need ....................................................................... 5 Proposed Action ......................................................................... 6
ARMY CORPS OF ENGINEERS SECONDARY IMPACTS CHECKLIST .................11
ARMY CORPS OF ENGINEERS SECONDARY IMPACTS CHECKLIST
SUPPLEMENTAL NARRATIVE ...........................................................13
ENV‐WT 404.04 RIP‐RAP. ...........................................................................15
MITIGATION .........................................................................................17
EXHIBITS
Exhibit A – Locus
Exhibit B – NHB Response
Exhibit C – USFWS NLEB Consultation
Exhibit D – 2010 WAP
Exhibit E – Floodplain
Exhibit F – Cultural Resource Effect Memo
Exhibit G – Scour Countermeasure Design Calculations
Exhibit H – Photographs
PLANS
Wetland Impact Plans
[email protected] or (603) 271-2147 NHDES Wetlands Bureau, Concord, NH 03303-0095
www.des.nh.gov Permit Application - Valid until 12/31/15 Page 1 of 4
NHDES-W-06-012
WETLANDS PERMIT APPLICATION Water Division/ Wetlands Bureau
Land Resources Management Check the status of your application: http://des.nh.gov/onestop
RSA/Rule: Env-Wq 100-900
1. REVIEW TIME: Indicate your Review Time below. Refer to Guidance Document A for instructions.
Standard Review (Minimum, Minor or Major Impact) Expedited Review (Minimum Impact only)
2. PROJECT LOCATION: Separate applications must be filed with each municipality that jurisdictional impacts will occur in.
ADDRESS: Sawyers Crossing Road TOWN/CITY: Swanzey
TAX MAP: NA BLOCK: NA LOT: NA UNIT: NA
USGS TOPO MAP WATERBODY NAME: Ashuelot River NA STREAM WATERSHED SIZE: 311 sq. mi. NA
LOCATION COORDINATES (If known): 72°17'11" 42°53'10" Latitude/Longitude UTM State Plane
3. PROJECT DESCRIPTION: Provide a brief description of the project outlining the scope of work. Attach additional sheets as needed to provide a detailed explanation of your project. DO NOT reply “See Attached" in the space provided below.
The NH Department of Transportation (NHDOT) proposes to repair and improve the riprap and scour protection of the Cresson Covered Bridge (State Bridge No. 136/143) that carries Sawyer’s Crossing Road over the Ashuelot River in Swanzey, New Hampshire (also known as Sawyer’s Crossing Covered Bridge). The project involves constructing scour countermeasures around the bridge abutments and center pier to prevent scour damage at the historic covered bridge site.
4. RELATED PERMITS, ENFORCEMENT, EMERGENCY AUTHORIZATION, SHORELAND, ALTERATION OF TERRAIN, ETC…
Shoreland Notification
5. NATURAL HERITAGE BUREAU & DESIGNATED RIVERS: See the Instructions & Required Attachments document for instructions to complete a & b below.
a. Natural Heritage Bureau File ID: NHB 15 - 1052 .
b. Designated River the project is in ¼ miles of: Ashuelot River ; and date a copy of the application was sent to Local River Advisory Committee: Month: Day: Year:
NA
Administrative
Use Only
Administrative
Use Only
Administrative
Use Only
File No.:
Check No.:
Amount:
Initials:
[email protected] or (603) 271-2147 NHDES Wetlands Bureau, Concord, NH 03303-0095
www.des.nh.gov Permit Application - Valid until 12/31/15 Page 2 of 4
6. APPLICANT INFORMATION (Desired permit holder)
LAST NAME, FIRST NAME, M.I.: Robert Landry
TRUST / COMPANY NAME:NHDOT MAILING ADDRESS: 7 Hazen Drive
TOWN/CITY: Concord STATE: NH ZIP CODE: 03302
EMAIL or FAX: [email protected] PHONE: 603 271-2731
ELECTRONIC COMMUNICATION: By initialing here: LRL , I hereby authorize DES to communicate all matters relative to this application electronically
7. PROPERTY OWNER INFORMATION (If different than applicant)
LAST NAME, FIRST NAME, M.I.:
TRUST / COMPANY NAME: MAILING ADDRESS:
TOWN/CITY: STATE: ZIP CODE:
EMAIL or FAX: PHONE:
ELECTRONIC COMMUNICATION: By initialing here , I hereby authorize DES to communicate all matters relative to this application electronically
8. AUTHORIZED AGENT INFORMATION
LAST NAME, FIRST NAME, M.I.: Chase, Vicki COMPANY NAME:Normandeau Assoc.
MAILING ADDRESS: 25 Nashua Road
TOWN/CITY: Bedford STATE: NH ZIP CODE: 03110
EMAIL or FAX: [email protected] PHONE: 603 637-1111
ELECTRONIC COMMUNICATION: By initialing here vpc , I hereby authorize DES to communicate all matters relative to this application electronically
9. PROPERTY OWNER SIGNATURE: See the Instructions & Required Attachments document for clarification of the below statements
By signing the application, I am certifying that:
1. I authorize the applicant and/or agent indicated on this form to act in my behalf in the processing of this application, and to furnish upon request, supplemental information in support of this permit application.
2. I have reviewed and submitted information & attachments outlined in the Instructions and Required Attachment document. 3. All abutters have been identified in accordance with RSA 482-A:3, I and Env-Wt 100-900. 4. I have read and provided the required information outlined in Env-Wt 302.04 for the applicable project type. 5. I have read and understand Env-Wt 302.03 and have chosen the least impacting alternative. 6. Any structure that I am proposing to repair/replace was either previously permitted by the Wetlands Bureau or would be considered
grandfathered per Env-Wt 101.47. 7. I have submitted a Request for Project Review (RPR) Form (www.nh.gov/nhdhr/review) to the NH State Historic Preservation Officer
(SHPO) at the NH Division of Historical Resources to be reviewed for the presence of historical/ archeological resources. 8. I authorize DES and the municipal conservation commission to inspect the site of the proposed project. 9. I have reviewed the information being submitted and that to the best of my knowledge the information is true and accurate. 10. I understand that the willful submission of falsified or misrepresented information to the New Hampshire Department of
Environmental Services is a criminal act, which may result in legal action. 11. I am aware that the work I am proposing may require additional state, local or federal permits which I am responsible for obtaining. 12. The mailing addresses I have provided are up to date and appropriate for receipt of DES correspondence. DES will not forward
returned mail.
Property Owner Signature
Print name legibly
/ / Date
[email protected] or (603) 271-2147 NHDES Wetlands Bureau, Concord, NH 03303-0095
www.des.nh.gov Permit Application - Valid until 12/31/15 Page 3 of 4
MUNICIPAL SIGNATURES
10. CONSERVATION COMMISSION SIGNATURE
The signature below certifies that the municipal conservation commission has reviewed this application, and: 1. Waives its right to intervene per RSA 482-A:11; 2. Believes that the application and submitted plans accurately represent the proposed project; and 3. Has no objection to permitting the proposed work.
Print name legibly Date
DIRECTIONS FOR CONSERVATION COMMISSION
1. Expedited review ONLY requires that the conservation commission’s signature is obtained in the space above.
2. Expedited review requires the Conservation Commission signature be obtained prior to the submittal of the original application to the Town/City Clerk for signature.
3. The Conservation Commission may refuse to sign. If the Conservation Commission does not sign this statement for any reason, the application is not eligible for expedited review and the application will reviewed in the standard review time frame.
11. TOWN / CITY CLERK SIGNATURE
As required by Chapter 482-A:3 (amended 2014), I hereby certify that the applicant has filed four application forms, four detailed plans, and four USGS location maps with the town/city indicated below.
Town/City Clerk Signature Print name legibly Town/City Date
DIRECTIONS FOR TOWN/CITY CLERK:
Per RSA 482-A:3,I
1. For applications where "Expedited Review" is checked on page 1, if the Conservation Commission signature is not present, NHDES will accept the permit application, but it will NOT receive the expedited review time.
2. IMMEDIATELY sign the original application form and four copies in the signature space provided above;
3. Return the signed original application form and attachments to the applicant so that the applicant may submit the application form and attachments to NHDES by mail or hand delivery.
4. IMMEDIATELY distribute a copy of the application with one complete set of attachments to each of the following bodies: the municipal Conservation Commission, the local governing body (Board of Selectmen or Town/City Council), and the Planning Board; and
5. Retain one copy of the application form and one complete set of attachments and make them reasonably accessible for public review.
DIRECTIONS FOR APPLICANT:
1. Submit the original permit application form bearing the signature of the Town/ City Clerk, additional materials, and the application fee to NHDES by mail or hand delivery.
[email protected] or (603) 271-2147 NHDES Wetlands Bureau, Concord, NH 03303-0095
www.des.nh.gov Permit Application - Valid until 12/31/15 Page 4 of 4
12. IMPACT AREA: For each jurisdictional area that will be/has been impacted, provide square feet and, if applicable, linear feet of impact Permanent: impacts that will remain after the project is complete. Temporary: impacts not intended to remain (and will be restored to pre-construction conditions) after the project is complete.
JURISDICTIONAL AREA PERMANENT
Sq. Ft. / Lin. Ft. TEMPORARY
Sq. Ft. / Lin. Ft.
Forested wetland ATF ATF
Scrub-shrub wetland ATF ATF
Emergent wetland ATF ATF
Wet meadow ATF ATF
Intermittent stream ATF ATF
Perennial Stream / River 2,301 / 185 ATF 10,019 / 60 ATF
Lake / Pond / ATF / ATF
Bank - Intermittent stream / ATF / ATF
Bank - Perennial stream / River 897 / 72 ATF 495 / 60 ATF
Bank - Lake / Pond / ATF / ATF
Tidal water / ATF / ATF
Salt marsh ATF ATF
Sand dune ATF ATF
Prime wetland ATF ATF
Prime wetland buffer ATF ATF
Undeveloped Tidal Buffer Zone (TBZ) ATF ATF
Previously-developed upland in TBZ ATF ATF
Docking - Lake / Pond ATF ATF
Docking - River ATF ATF
Docking - Tidal Water ATF ATF
TOTAL 3,198 / 257 10,514 / 120
13. APPLICATION FEE: See the Instructions & Required Attachments document for further instruction
Minimum Impact Fee: Flat fee of $ 200
Minor or Major Impact Fee: Calculate using the below table below
Permanent and Temporary (non-docking) 13,712 sq. ft. X $0.20 = $ 2,742.40
Temporary (seasonal) docking structure: sq. ft. X $1.00 = $
Permanent docking structure: sq. ft. X $2.00 = $
Projects proposing shoreline structures (including docks) add $200 = $
Total = $
The Application Fee is the above calculated Total or $200, whichever is greater = $ 2,742.40
STANDARD DREDGE AND FILL WETLAND APPLICATION
Swanzey 23737 5 Normandeau Associates, Inc.
Attachment A
Env-Wt 302.04 Requirements for Application Evaluation - For any major or minor project, the applicant shall demonstrate by plan and example that the following factors have been considered in the project’s design in assessing the impact of the proposed project to areas and environments under the department’s jurisdiction. Respond with statements demonstrating:
1. The need for the proposed impact.
Project Description
The NH Department of Transportation (NHDOT) proposes to repair and improve the
riprap and scour protection of the Cresson Covered Bridge (State Bridge No. 136/143) that
carries Sawyers Crossing Road over the Ashuelot River in Swanzey, New Hampshire
(also known as Sawyers Crossing Covered Bridge). The State of NH received funds from
the National Historic Covered Bridge Preservation Program for this municipally‐owned
historic covered bridge. The project involves constructing scour countermeasures around
the bridge abutments and center pier to prevent scour damage at the historic covered
bridge site.
Existing Bridge
Cresson Covered Bridge carries Sawyers Crossing Road over the Ashuelot River in
Swanzey, NH (Exhibit A – Locus). The bridge was originally constructed in 1859 and
rehabilitated in 1983 and again in 1996. It is an unsymmetrical town lattice truss structure
and spans 159 feet over the river. The bridge consists of two spans 61’‐6” and 77’‐3” from
center‐to‐center of bearings and has a vertical clearance of 12’‐9”. The existing bridge has
a one lane roadway and has a weight posting of 3 tons ‐ passenger cars only. The piers
are constructed of stone masonry on timber matting and footing stones. A previous
bridge rehabilitation project included installing stone fill at the west abutment and pier.
The stone fill is still in place at the abutment, but is not entirely intact at the pier. No
stone fill was installed at the east abutment.
Purpose and Need
A scour Critical Bridge Plan of Action (POA) was prepared in June of 2010 for Cresson
Covered Bridge. As part of the POA, a scour analysis was performed in order to
investigate contraction and pier scour components of total scour. It was determined that
Cresson Covered Bridge is scour critical. The embedment depth is unknown and the
riverbed is highly susceptible to erosion and scour from fast flowing waters during flood
events. Sediment buildup has been noted on pier footings and scour protection is needed
on pier noses. It was the recommendation of this investigation that partially grouted
riprap be installed at Cresson Covered Bridge. Subsequently, it was determined that
STANDARD DREDGE AND FILL WETLAND APPLICATION
Swanzey 23737 6 Normandeau Associates, Inc.
other scour protection methods would be more appropriate, as described below.
Proposed Action
The POA report determined that the bridge’s scour critical rating was “critical during
floods”; meaning the bridge and abutments are susceptible to undermining from erosive
forces during high flows. The POA recommended scour countermeasures at only the
west abutment and pier. Due to evidence of undercutting along the river bank, NHDOT
proposes to place riprap at the east abutment as well. Standard riprap, rather than
partially grouted riprap, will be suitable at each abutment location. Additional scour
countermeasures in the form of prefabricated concrete “A‐Jacks” ® are proposed at the
pier location. A‐Jacks are concrete interlocking six‐pronged units that are prefabricated
by ConTech Engineered Solutions LLC and installed as depicted in Photo 8 (Exhibit H ‐
Photographs).
2. That the alternative proposed by the applicant is the one with the least impact to wetlands
or surface waters on site.
Impacts to wetlands have been minimized to the extent possible. The No‐Build alternative
would affect no wetlands but would not meet the need to improve to safety of the bridge.
The project proposes to use a causeway for access to the work area. While a trestle would
have a smaller temporary impact footprint on the riverbed, it would be prohibitively
expensive, costing an estimated $460,000 compared with $81,000 for a temporary causeway. 3. The type and classification of the wetlands involved.
Wetlands proposed to be impacted include Riverine, Lower Perennial, Unconsolidated
Bottom, Sand Substrate, Permanently Flooded (R2UB2H); and jurisdictional Riverbank. 4. The relationship of the proposed wetlands to be impacted relative to nearby wetlands and
surface waters.
The jurisdictional resources proposed to be affected all are part of the Ashuelot River. 5. The rarity of the wetland, surface water, sand dunes, or tidal buffer zone area.
The Ashuelot River is typical of perennial rivers in New Hampshire. 6. The surface area of the wetlands that will be impacted.
The project as proposed will involve 10,514 square feet of temporary impact and 3,198
square feet of permanent impact to wetland resources.
STANDARD DREDGE AND FILL WETLAND APPLICATION
Swanzey 23737 7 Normandeau Associates, Inc.
7. The impact on plants, fish and wildlife including, but not limited to:
a. Rare, special concern species; b. State and federally listed threatened and endangered species; c. Species at the extremities of their ranges; d. Migratory fish and wildlife; e. Exemplary natural communities identified by the DRED-NHB; and f. Vernal pools.
A data request to the New Hampshire Natural Heritage Bureau was made and the response
indicated that there are known occurrences of state and federally listed dwarf
wedgemussels within the project area. (Exhibit B ‐ NHB Response) FHWA has initiated
consultation with the U.S. Fish and Wildlife Service as required under Section 7 of the
Endangered Species Act. Results of the consultation will be forwarded to NHDES when
available.
An environmental review was conducted through the US Fish and Wildlife Service’s
(USFWS) online Information for Planning and Conservation website (IPaC). The response
indicated that in addition to the dwarf wedgemussel, the federally threatened northern
long‐eared bat (Myotis septentrionalis) has the potential to occur within the project area.
Informal consultation performed for the northern long‐eared bat under the “Federal Highway
Administration (FHWA) and Federal Railroad Administration (FRA) Range‐wide Programmatic
Informal Consultation for Indiana Bat and Northern Long‐eared Bat” indicated that there will be
no effect to this species from the proposed project. (Exhibit C – USFWS NLEB Consultation)
8. The impact of the proposed project on public commerce, navigation and recreation.
The project will improve public commerce, navigation, and recreation by protecting the
existing pier and bridge abutments for the Cresson Covered Bridge. 9. The extent to which a project interferes with the aesthetic interests of the general public.
For example, where an applicant proposes the construction of a retaining wall on the bank
of a lake, the applicant shall be required to indicate the type of material to be used and the
effect of the construction of the wall on the view of other users of the lake.
The project will not interfere with the aesthetic interests of the general public. The purpose
of the project is to preserve this historic structure. 10. The extent to which a project interferes with or obstructs public rights of passage or
access. For example, where the applicant proposes to construct a dock in a narrow
channel, the applicant shall be required to document the extent to which the dock would
block or interfere with the passage through this area.
STANDARD DREDGE AND FILL WETLAND APPLICATION
Swanzey 23737 8 Normandeau Associates, Inc.
The project will not interfere with public rights of passage or access. Traffic will be
maintained over the bridge throughout construction. 11. The impact upon abutting owners pursuant to RSA 482-A:11, II. For example, if an
applicant is proposing to rip-rap a stream, the applicant shall be required to document the
effect of such work on upstream and downstream abutting properties.
The impact to abutting property owners will be positive, as it will improve safety at the
bridge. 12. The benefit of a project to the health, safety, and well being of the general public.
The project will improve health, safety, and well‐being of the general public. 13. The impact of a proposed project on quantity or quality of surface and ground water. For
example, where an applicant proposes to fill wetlands the applicant shall be required to
document the impact of the proposed fill on the amount of drainage entering the site
versus the amount of drainage exiting the site and the difference in the quality of water
entering and exiting the site.
There will be no impact to the quantity or quality of surface and ground water. 14. The potential of a proposed project to cause or increase flooding, erosion, or
sedimentation.
The project will not cause flooding, erosion, or sedimentation. All appropriate erosion and
sedimentation controls will be used during construction to prevent sedimentation or
turbidity in the Ashuelot River.
15. The extent to which a project that is located in surface waters reflects or redirects current
or wave energy which might cause damage or hazards.
The purpose of the scour countermeasures is to redirect river currents that are causing
ongoing erosion at the bridge piers. 16. The cumulative impact that would result if all parties owning or abutting a portion of the
affected wetland or wetland complex were also permitted alterations to the wetland
proportional to the extent of their property rights. For example, an applicant who owns
STANDARD DREDGE AND FILL WETLAND APPLICATION
Swanzey 23737 9 Normandeau Associates, Inc.
only a portion of a wetland shall document the applicant’s percentage of ownership of that
wetland and the percentage of that ownership that would be impacted.
If all abutters to the project also installed scour countermeasures in the Ashuelot River there
would be additional cumulative impacts, however, this is unlikely to occur. 17. The impact of the proposed project on the values and functions of the total wetland or
wetland complex.
The project will have no impact to the values and functions of the Ashuelot River. 18. The impact upon the value of the sites included in the latest published edition of the
National Register of Natural Landmarks, or sites eligible for such publication.
NA
19. The impact upon the value of areas named in acts of congress or presidential
proclamations as national rivers, national wilderness areas, national lakeshores, and such
areas as may be established under federal, state, or municipal laws for similar and related
purposes such as estuarine and marine sanctuaries.
The Ashuelot River is a Designated River under NH RSA 483, the New Hampshire Rivers
Management and Protection Program. Coordination has taken place with the Local Rivers
Advisory Committee and a copy of this application will be sent to them for their review.
20. The degree to which a project redirects water from one watershed to another.
NA Additional Comments
None.
NH PGP – Appendix B August 20121
New Hampshire Programmatic General Permit (PGP)Appendix B - Corps Secondary Impacts Checklist
(for inland wetland/waterway fill projects in New Hampshire)
1. Attach any explanations to this checklist. Lack of information could delay a Corps permit determination.2. All references to “work” include all work associated with the project construction and operation. Work includes filling, clearing, flooding, draining, excavation, dozing, stumping, etc.3. See PGP, GC 5, regarding single and complete projects. 4. Contact the Corps at (978) 318-8832 with any questions.1. Impaired Waters Yes No1.1 Will any work occur within 1 mile upstream in the watershed of an impaired water? See http://des.nh.gov/organization/divisions/water/wmb/section401/impaired_waters.htmto determine if there is an impaired water in the vicinity of your work area.* 2. Wetlands Yes No2.1 Are there are streams, brooks, rivers, ponds, or lakes within 200 feet of any proposed work?2.2 Are there proposed impacts to SAS, shellfish beds, special wetlands and vernal pools (see PGP, GC 26 and Appendix A)? Applicants may obtain information from the NH Department of Resources and Economic Development Natural Heritage Bureau (NHB) website, www.nhnaturalheritage.org, specifically the book Natural Community Systems of New Hampshire.2.3 If wetland crossings are proposed, are they adequately designed to maintain hydrology, sediment transport & wildlife passage?2.4 Would the project remove part or all of a riparian buffer? (Riparian buffers are lands adjacent to streams where vegetation is strongly influenced by the presence of water. They are often thin lines of vegetation containing native grasses, flowers, shrubs and/or trees that line the stream banks. They are also called vegetated buffer zones.)2.5 The overall project site is more than 40 acres.2.6 What is the size of the existing impervious surface area?2.7 What is the size of the proposed impervious surface area?2.8 What is the % of the impervious area (new and existing) to the overall project site?3. Wildlife Yes No3.1 Has the NHB determined that there are known occurrences of rare species, exemplary natural communities, Federal and State threatened and endangered species and habitat, in the vicinity of the proposed project? (All projects require a NHB determination.)3.2 Would work occur in any area identified as either “Highest Ranked Habitat in N.H.” or “Highest Ranked Habitat in Ecological Region”? (These areas are colored magenta and green, respectively, on NH Fish and Game’s map, “2010 Highest Ranked Wildlife Habitat by Ecological Condition.”) Map information can be found at: ��PDF: www.wildlife.state.nh.us/Wildlife/Wildlife_Plan/highest_ranking_habitat.htm.��Data Mapper: www.granit.unh.edu.��GIS: www.granit.unh.edu/data/downloadfreedata/category/databycategory.html.
x
x
x
x
x
x
x
x
NA
no changeno change
NH PGP – Appendix B August 20121
3.3 Would the project impact more than 20 acres of an undeveloped land block (upland, wetland/waterway) on the entire project site and/or on an adjoining property(s)?3.4 Does the project propose more than a 10-lot residential subdivision, or a commercial or industrial development?3.5 Are stream crossings designed in accordance with the PGP, GC 21?4. Flooding/Floodplain Values Yes No4.1 Is the proposed project within the 100-year floodplain of an adjacent river or stream?4.2 If 4.1 is yes, will compensatory flood storage be provided if the project results in a loss of flood storage?5. Historic/Archaeological ResourcesFor a minor or major impact project - a copy of the Request for Project Review (RPR) Form (www.nh.gov/nhdhr/review) shall be sent to the NH Division of Historical Resources as required on Page 5 of the PGP***Although this checklist utilizes state information, its submittal to the Corps is a Federal requirement.** If project is not within Federal jurisdiction, coordination with NH DHR is not required under Federal law..`
x
x
x
x
x
x
STANDARD DREDGE AND FILL WETLAND APPLICATION
Swanzey 23737 13 Normandeau Associates, Inc.
Army Corps of Engineers Secondary Impacts Checklist Supplemental Narrative
1. Impaired Waters
1.1 Will any work occur within 1 mile upstream in the watershed of an impaired water?
Yes. Aquatic life in the Ashuelot River is impaired by Aluminum, Benthic‐
Macroinvertebrate Bioassessments, Habitat Assessments, Lead, and pH. Primary contact
recreation is impaired by E. coli. The proposed project is not anticipated to have any effect
on these impairments as it involves only the installation of scour protection measures.
2. Wetlands
2.1 Are there are streams, brooks, rivers, ponds, or lakes within 200 feet of any proposed
work?
Yes. The proposed project is in the Ashuelot River.
2.4 Would the project remove part or all of a riparian buffer? (Riparian buffers are lands
adjacent to streams where vegetation is strongly influenced by the presence of water.
They are often thin lines of vegetation containing native grasses, flowers, shrubs and/or
trees that line the stream banks. They are also called vegetated buffer zones.)
Yes. A small amount of shrub vegetation, and two small trees, will be removed to provide
access for machinery to the work area.
3. Wildlife
3.1 Has the NHB determined that there are known occurrences of rare species, exemplary
natural communities, Federal and State threatened and endangered species and habitat,
in the vicinity of the proposed project? (All projects require a NHB determination.)
Yes. A data request to the New Hampshire Natural Heritage Bureau was made and the
response indicated that there are known occurrences of state and federally listed dwarf
wedgemussels within the project area (Exhibit B ‐ NHB Response). FHWA has initiated
consultation with the U.S. Fish and Wildlife Service as required under Section 7 of the
Endangered Species Act. Results of the consultation will be forwarded to NHDES when
available.
An environmental review was conducted through the US Fish and Wildlife Service’s
(USFWS) online Information for Planning and Conservation website (IPaC). The response
indicated that in addition to the dwarf wedgemussel, the federally threatened northern
long‐eared bat (Myotis septentrionalis) has the potential to occur within the project area.
Informal consultation performed for the northern long‐eared bat under the “Federal Highway
Administration (FHWA) and Federal Railroad Administration (FRA) Range‐wide Programmatic
STANDARD DREDGE AND FILL WETLAND APPLICATION
Swanzey 23737 14 Normandeau Associates, Inc.
Informal Consultation for Indiana Bat and Northern Long‐eared Bat” indicated that there will be
no effect to this species from the proposed project. (Exhibit C – USFWS NLEB Consultation)
3.2 Would work occur in any area identified as either “Highest Ranked Habitat in N.H.”
or “Highest Ranked Habitat in Ecological Region”?
Yes. This portion of the river is identified as Tier 1 Habitat in the 2010 NH Wildlife Action
Plan (Exhibit D – 2010 WAP).
4. Flooding/Floodplain Values
4.1 Is the proposed project within the 100‐year floodplain of an adjacent river or stream?
Yes. The project lies within the FEMA mapped floodplain of the Ashuelot River (Exhibit E –
Floodplain). However, there will be no alterations to floodplain storage.
5. Historic/Archaeological Resources
For a minor or major impact project ‐ a copy of the Request for Project Review (RPR)
Form (www.nh.gov/nhdhr/review) shall be sent to the NH Division of Historical
Resources as required on Page 5 of the PGP.
A Phase lA‐1B archaeological survey undertaken for the site concluded that that the
proposed construction activities within the APE are unlikely to adversely affect intact
archaeological resources associated with Pre‐Contact cultures or the Euroamerican
occupation of Swanzey. The study recommended no further archaeological survey, so long
as the project parameters remain within the limits of the APE and do not include subsurface
impacts. NHDHR concurred with this conclusion on 8/19/14. (Exhibit F – Cultural Resource
Effect Memo)
STANDARD DREDGE AND FILL WETLAND APPLICATION
Swanzey 23737 15 Normandeau Associates, Inc.
Env-Wt 404.04 Rip-rap.
(a) Rip-rap applications shall be considered only where the applicant demonstrates that anticipated turbulence, flows, restricted space, or similar factors render vegetative and diversion methods physically impractical.
A Scour Critical Bridge Plan of Action (POA) was prepared in June of 2010 for Cresson
Covered Bridge. As part of the POA, a scour analysis was performed in order to investigate
contraction and pier scour components of total scour. It was determined that Cresson
Covered Bridge is scour critical. The embedment depth is unknown and the riverbed is
highly susceptible to erosion and scour from fast flowing waters during flood events.
Sediment buildup has been noted on pier footings and scour protection is needed on pier
noses. It was the recommendation of this investigation that partially grouted riprap be
installed at Cresson Covered Bridge. Subsequently, it was determined that other scour
protection methods would be more appropriate.
(b) Applications for rip-rap shall include:
(1) Designation of a minimum and maximum stone size;
Class III riprap will be used at the bridge abutments. Riprap design calculations are
attached to this application (Exhibit G – Scour Countermeasure Design Calculations.)
Additional scour countermeasures in the form of prefabricated concrete “A‐Jacks” ® are
proposed at the pier location. A‐Jacks are concrete interlocking six‐pronged units that are
prefabricated by ConTech Engineered Solutions LLC.
(2) Gradation;
As above.
(3) Minimum rip-rap thickness;
Riprap at the bridge abutments will be placed in a 2’ thick layer.
(4) Type of bedding for stone;
Riprap at the abutments will be placed on a 6” layer of very coarse crushed stone. A‐Jacks
will be placed on a 6” layer of fine gradation crushed stone, as depicted on Sheet 6 of
Wetland Impact Plans, “Scour Mitigation Details”.
(5) Cross-section and plan views of the proposed installation;
See Sheet 6 of Wetland Impact Plans, “Scour Mitigation Details”.
(6) Sufficient plans to clearly indicate the relationship of the project to fixed points of reference, abutting properties, and features of the natural shoreline; and
See Sheet 6 of Wetland Impact Plans, “Scour Mitigation Details”.
STANDARD DREDGE AND FILL WETLAND APPLICATION
Swanzey 23737 16 Normandeau Associates, Inc.
(7) A description of anticipated turbulence, flows, restricted space, or similar factors that would render vegetative and diversion methods physically impractical.
The POA used information from the Cheshire Countywide FEMA Flood Insurance Study
and a field soil classification to calculate a pier scour estimate. Based on these
computations, it was estimated that there is the potential for eleven feet of scour at the
bridge pier during the 100‐year storm event. Vegetative stabilization and diversion
methods to prevent scour are physically impractical at this location.
STANDARD DREDGE AND FILL WETLAND APPLICATION
Swanzey 23737 17 Normandeau Associates, Inc.
Mitigation
This project involves only the installation of scour countermeasures for infrastructure
protection. As such, it is exempt from the requirement to mitigate under Env‐Wt 302.03 (c)
(2) c.
Project Location
Service Layer Credits: Copyright:© 2013 National Geographic Society, i-cubed
Pro
ject No
: 86
753.0
9
Dra
wn
By: vch
ase
Date
: 9/8/20
15
NHDOT 23737
CRESSON COVERED BRIDGE
25 Nashua Road Bedford, NH 03110(603) 472-5191 www.normandeau.com
SWANZEY, NH
SCALE:1:24,000
0 2,000 4,0001,000Feet
SEPTEMBER, 2015
EXHIBIT A - LOCUS
Mem
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185
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488
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H
0330
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56
To:
Vic
ki C
hase
, Nor
man
deau
Ass
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tes
25
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hua
Road
Bedf
ord,
NH
033
01-5
022
From
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Re
view
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Nat
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Her
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Bur
eau
N
HB
File
ID:
NH
B15-
1052
To
wn:
Sw
anze
y Lo
catio
n:
Saw
yer's
Cro
ssin
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oad
D
escr
iptio
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NH
DO
T pr
opos
es to
repl
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scou
r pro
tect
ion
ston
e ar
ound
the
pier
and
abu
tmen
ts o
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Cre
sson
Cov
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Brid
ge.
cc:
Kim
Tut
tle
As r
eque
sted
, I h
ave
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ched
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dat
abas
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of r
are
spec
ies a
nd e
xem
plar
y na
tura
l com
mun
ities
, with
the
follo
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sults
.
Com
men
ts:
Thi
s site
is w
ithin
an
area
flag
ged
for
poss
ible
impa
cts o
n th
e fe
dera
lly-li
sted
Ala
smid
onta
het
erod
on (d
war
f wed
gem
usse
l) in
the
Ash
uelo
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iver
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Inve
rteb
rate
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H F
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SC”
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Nat
ural
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at th
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NH
F&
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logi
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ly b
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Exh
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B
NHB15-1052 EOCODE: IMBIV02030*021*NH
New Hampshire Natural Heritage Bureau - Animal Record Dwarf Wedge Mussel (Alasmidonta heterodon)
Legal Status Conservation Status Federal: Listed Endangered Global: Critically imperiled due to rarity or vulnerability State: Listed Endangered State: Critically imperiled due to rarity or vulnerability
Description at this LocationConservation Rank: Fair quality, condition and/or landscape context ('C' on a scale of A-D). Comments on Rank: Detailed Description: 2010: Ashuelot River - Cresson Bridge to Homestead Dam: Critical habitat throughout this
stretch of river. 496 mussels collected and relocated. Relocation site 1: 17 animals relocated from vicinity of Thompson covered bridge. Relocation site 2: 166 animals relocated from pre-drawdown survey. Relocation site 3: 313 animals relocated from surveys conducted during drawdown.2003: Obs_id 2421: 1 adult male observed. Obs_id 2459: 14 seen, age and sex unknown. 2001: A total of 13 shells at six sites along a two-mile stretch of river. Upstream of this stretch, four sites in a 1.25-mile stretch downstream of the confluence of the Ashuelot and The Branch each had no A. heterodon found. Sites 5 - 8: one shell observed. Site 10: 5 shells and some juveniles observed. Site 11: four shells observed.
General Area: 2010: Ashuelot River - Cresson Bridge to Homestead Dam: High quality habitat throughout stretch of river. Mussels occurred on stable banks, often in less than 6 inches of water.2003: Freshwater - Stream or river (Obs_id 2421). 2001: Up- and down-stream of an effluent pipe for a wastewater treatment plant. Site 5: Very slow flow (less than 0.05 m/s), substrate of large boulders and sand. Canopy fairly dense, and the river is well shaded. Site 6: Flow fairly quick (0.2-0.4 m/s). River is 10-15 yards wide, 1-4 feet deep, with a substrate of large boulders, gravel, and sand. Heavy riparian canopy. Site 7: Slow flow (less than 0.10 m/s). River is 1-6 feet wide, with a substrate a mix of sand, gravel, and boulders. Receives a lot of sunlight, since riparian canopy minimal. Site 8: Very slow flow (less than 0.10 m/s). River is 20-25 yards wide and less than 3 feet deep except for deeper spots along the banks. Substrate is almost entirely sand with silt and clay on the margins and much woody debris (almost no stable substrate). Little riparian canopy. Site 10: Flow rate very slow (less than 0.10 m/s). River is 2-6 feet (up to 11 feet) deep. Substrate mostly sand and silt but becoming very rocky where the mussels were found. Woody debris common throughout. Site 11: Very slow flow (less than 0.10 m/s). River generally 2-6 feet deep, reaching 8-10 feet. Substrate rocky (boulders, cobble, sand) in mussel area.
General Comments: 2010: Mussel survey was coordinated with the removal of the Homestead Dam on the Ashuelot River, as well as repairs to the Thompson covered bridge. Prior to bridge repairs, all mussels found near the footprint of the construction work were relocated to Relocation site 1. Prior to dam removal, all mussels found upstream to Cresson Bridge were collected and relocated to Relocation site 2. During the impoundment drawdown following the dam removal, all mussels observed were collected and relocated to Relocation site 3.2003: Scuba search of 500 yard site (2.5 hrs. x 2 people)found one large (>40mm) male DWM. Tesselated darters abundant throughout. Also A. undulata (>50 live) and S. undulatus (20-50 live). Lat./long. by Terrain Navigator near mid-point of site (Obs_id 2421). Information taken from "Freshwater Mussels of the Ashuelot River -- Keene to Hinsdale, August 2003," written by Ethan Nadeau of Biodrawversity consulting firm. Report submitted to NHFG and USFWS (Obs_id 2459).
Management Comments:
2001: Diverse mussel communities at sites 10 and 11, 700 and 1500 yards downstream of the effluent pipe, respectively, suggest no lasting negative consequences from the wastewater effluent.
Location Survey Site Name: Keene Managed By: Dickinson Memorial Forest
NHB15-1052 EOCODE: IMBIV02030*021*NH
County: Cheshire Town(s): Swanzey Size: 61.8 acres Elevation: Precision: Within (but not necessarily restricted to) the area indicated on the map. Directions: 2010: Relocation sites 1 & Upstream of Cresson Bridge. Relocation site 3: Downstream of Cresson
Bridge.2003: Obs_id 2421: 30-60 meters upstream of the covered bridge at Swanzey Dam. (Swanzey Dam Site #16, Freshwater Mussels of the Ashuelot River -Keene to Hinsdale, August 2003) (Obs_id 2421). From NH Rte 10 in Swanzey, take Sawyers Crossing Road ca. 2 miles east to the covered bridge over the Ashuelot River. 2001: Site 5: canoe upstream ca. 1.6 miles to where powerlines border the river upstream of a bend. Site 6: ca. 900 yards downstream of site 5 and 1000 yards upstream from the wastewater treatment plant effluent pipe. Site 7: ca. 600 yards upstream of the effluent pipe, just downstream of a bend in the river. Site 8: ca. 100 yards upstream of the effluent pipe, along the western shore. Site 10: ca. 200-300 yards upstream of the covered bridge, on the western side of the river. Site 11: canoe downstream of the covered bridge ca. 700 yards to an area on the eastern side of the river downstream of a sharp bend with a steep, rocky bank.
Dates documented First reported: 2001-08-08 Last reported: 2010-08-12
The U.S. Fish & Wildlife Service has jurisdiction over Federally listed species. Please contact them at 70 Commercial Street, Suite 300, Concord NH 03301 or at (603) 223-2541.
1
Federal Highway Administration (FHWA) and Federal Railroad Administration (FRA) Range-wide Programmatic Informal Consultation for
Indiana Bat and Northern Long-eared Bat�
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1 Available through IPaC System Official Species List: https://ecos.fws.gov/ipac/
9/8/15
FHWA
NHDOT
Ron Crickard
Chief, Project Management
(603) 271-7966
05E1NE00-2015-SLI-1947
Swanzey 23737 Scour Protection
Scour protection Repair of the Cresson Covered Bridge (Bridge No. 136/143)
2
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2 Coordinate with local Service field office for appropriate dates.
✔
3
11. For Bridge/Structure Work Projects:
a. Proposed work:
b. Timing of work:
c. Evidence of bat activity on bridge/structure:
d. If applicable, verify that superstructure work will not bother roosting bats in any way:
e. If applicable, verify that bridge/structure work will occur only in the winter months:
12. Please confirm the following:
Proposed project(s) adhere to the criteria of the range-wide programmatic informal BA (see Section 2.0).
All applicable AMMs will be implemented, including3:
Tree Removal AMM 1:
Tree Removal AMM 2:
Tree Removal AMM 3:
Tree Removal AMM 4:
Bridge AMM 1:
Bridge AMM 2:
Bridge AMM 3:
Bridge AMM 4:
Structure AMM 1:
Structure AMM 2:
Structure AMM 3:
Structure AMM 4:
Lighting AMM 1:
Lighting AMM 2:
Dust Control AMM 1:
Water Control AMM 1:
Water Control AMM 2:
Water Control AMM 3:
Water Control AMM 4:
Water Control AMM 5:
Water Control AMM 6:
Wetland/Stream Protection AMM 1:
Wetland/Stream Protection AMM 2:
Wetland/Stream Protection AMM 3:
Wetland/Stream Protection AMM 4:
Wetland/Stream Protection AMM 5:
Wetland/Stream Protection AMM 6:
3 See AMMs Fact Sheet (Appendix B) for more information on the following AMMs.
Project Location
Service Layer Credits: Copyright:© 2013 National Geographic Society, i-cubed
Pro
ject No
: 86
753.0
9
Dra
wn
By: vch
ase
Date
: 8/26/2
015
NHDOT 23737
CRESSON COVERED BRIDGE
25 Nashua Road Bedford, NH 03110(603) 472-5191 www.normandeau.com
SWANZEY, NH
0 2,000 4,0001,000Feet
AUGUST, 2015
EXHIBIT DWAP TIER 1 HABITAT
LegendWAP TiersGRIDCODE
Highest Ranked Habitat in NH
Highest Ranked Habitat in Biological Region
Supporting Landscapes
¯1:12,000
Project Location
Service Layer Credits: Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics,CNES/Airbus DS, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the
Pro
ject No
: 86
753.0
9
Dra
wn
By: vch
ase
Date
: 9/9/20
15
NHDOT 23737
CRESSON COVERED BRIDGE
25 Nashua Road Bedford, NH 03110(603) 472-5191 www.normandeau.com
SWANZEY, NH
SCALE:
0 2,000 4,0001,000Feet
SEPTEMBER, 2015
EXHIBIT E - FLOODPLAINS Data Source: Federal Emergency Management Agency. DIGITAL FLOOD INSURANCE RATE MAP DATABASE,CHESHIRE COUNTY, NEW HAMPSHIRE 1986.
Legend
1:2,400
FEMA MAPPED FLOODPLAIN WITH BASE FLOOD ELEVATION
Cultural Resources Effect Memo
Project Town: Swanzey (::;
State No.: 23737 IT fli S ~ Date: 3/9/2015
Federal No. (as applicable): Swanzey, X-A002(758)
Pursuant to attached concurrence memo, and for the purpose of compliance with the regulations of National Historic Preservation Act and the Advisory Council on Historic Preservation's procedures for the Protection of Historic Properties (36 CFR 800), the NH Division of Historical Resources and, when applicable, the NH Division of the Federal Highway Administration or the US Army Corps of Engineers have coordinated the identification and evaluation of cultural resources relative to the repair and improvement of the rip rap and scour protection of the Cresson Covered Bridge (State Bridge No. 136/143) that carries Sawyer's Crossing Road over the Ashuelot River in Swanzey, New Hampshire. The State of NH received funds from the National Historic Covered Bridge Preservation Program for this municipally-owned historic covered bridge. The project involves constructing scour countermeasures to prevent scour damage at the historic covered bridge site. Bridge impacts are limited to scour protection areas.
A Phase lA-1B archaeological survey undertaken for the site concluded that that the proposed construction activities within the APE are unlikely to adversely affect intact archaeological resources associated with Pre-Contact cultures or the Euroamerican occupation of Swanzey. The study recommended no further archaeological survey, so long as the project parameters remain within the limits of the APE and do not include subsurface impacts. NHDHR concurred with this conclusion on 8/19/14 (See attached concurrence memo).
Based on a review of the project, as presented on this date, it has been determined that:
o No Historic or Archaeological Properties will be Affected
[2;1 There will be No Adverse Effect on Historic or Archaeological Properties Describe any outstanding commitments: Project parameters shall remain within previously delineated APE, and there shall be no subsurface impacts,
o There will be an Adverse Effect on Historic or Archaeological Properties or Resources describe the effect, measures to minimize harm and proposed mitigation. _______________ _ _______________________________ (.attach pages as Necessary).
In accordance with the Advisory Council's regulations, we will continue to consult, as appropriate, as this project proceeds.
The NH State Historic Preservation Officer concurs with these findings~: y~~~~~~~:2::~~~~.:::. :.-__
There Will Be: No 4(f) [2;1; Programmatic 4(f) 0; Full 4 (f) 0; or
o A finding of de minimis 4(f) impact as stated: In addition, with NHDHR concurrence of no adverse effect for the above undertaking, and in accordance with 23 CFR 774, FHWA intends to, and by signature below, does make a . finding of de minimis impact. NHDHR's signature represents concurrence with both the no adverse effect determination an the d minimis findings. Parties to the Section 106 process have been consulted and their concerns
h e,""o "'""~" 't,ref7':; ~;frem'''" of S~f"" 4{D h,,~ '- ,.f,f",d, Fed a1 Highway Adnnmstration
Army Corps of Engineers
Cc:FHWA, NHDHR, ACOE ( <= as applicable fl )
Job Swanzey 23737 Computed By TPL Date 2/24/2014
Description Sawyers Crossing over Ashuelot River Checked By FB Date 2/28/2014
Riprap
References:
1. NHDOT/CHA Scour Critical Bridge Plan of Action Report , June, 2010
Determine Required Thickness and Layout Dimensions for Riprap Design Guide 14 Ref. 2
Need to determine required riprap size Example 14.4 Ref. 2
Determine appropriate SBR
SBR < 5.0 From review of Existing Site Plan
Channel Avg Velocity, Vavg = 3.60 fps Ref. 1
Flow depth adjacent to abut., y = 11.90 ft = WSE -El. @ Toe of Abut. Ref. 1
Determine d50
gravitational accel, g = 32.20 ft/s2
Specific gravity of riprap, Ss = 2.65
Froude Number, Fr = 0.184
Abutment Type = vertical wall
Abutment Type Factor, K = 1.02
d50 = 0.25 ft Equation 14.1 Ref. 2
Select Class III Riprap Table 12.1 Ref. 2
Use d50 = 1.00 ft
Determine Minimum Riprap thickness Assumed placed in dry conditions
tmin = 2.00 ft = max (1.5 d50 or d100) Section 14.3 Ref. 2
Contraction Scour = 0.00 ft Ref. 1
Bed forms = 0.00 ft Ref. 1
Use tmin = 2.00 ft Use tact = 2.00 ft
Determine Minimum Riprap extents
minimum extent into floodplain = 18 ft =1.5 y Section 12.4 Ref. 2
extent downstream embank. = 19 ft =75% of 25 feet for partially grouted riprap
197 Loudon Road, Suite 310
Concord, NH 03301
2. HEC-23: Bridge Scour & Stream Instability Countermeasures: Experience, Selection, & Design Guidance -
3rd Edition, Vol. I & II
T:\Projects\New Hampshire\Swanzey 23737 Winchester 23738\23737_23738\Computations\Revetment Design - Swanzey\Riprap Design Calcs_Swanzey 23737.xlsx ABUT
Job Swanzey 23737 Computed By TPL Date 11/20/2013
Description Sawyers Crossing over Ashuelot River Checked By FB Date 2/24/2014
GRANULAR FILTER DESIGN
References:
1. NHDOT River Bed Sample Sieve Test Results, October 18, 2013
3. NHDOT Standard Specs for Road & Bridge Construction, 2010
Determine Key Indices for Base Soil
d50s = 0.18 mm Interp. Grain Dist Chart Ref. 1
d10s = 0.075 mm Ref. 1
d60s = 0.203 mm Ref. 1
Cu = 2.71 = d60/d10
Determine Key Indices for Riprap Use Class III Table 12.1 Ref. 2
d50 = 305.00 mm Table 12.1 Ref. 2
d15 = 203.00 mm Table 12.1 Ref. 2
d85 = 406.00 mm Table 12.1 Ref. 2
Cu = 2.00 = d85/d15
Determine Maximum Allowable d50R for Riprap directly on Base Soil
A50 = 12 Using Cisten-Ziems chart (Fig. 16.2) Ref. 2
d50R = 2.16 mm = A50(d50s)
NG, FILTER REQUIRED
Determine Key Indices for Filter Use NHDOT Spec 304.4 - Crushed Stone (Fine)
d50 = 4.75 mm Section 304, Table 1 Ref. 3
d10 = 1.50 mm Section 304, Table 1 Ref. 3
d60 = 19.00 mm Section 304, Table 1 Ref. 3
Cu = 12.67 = d60/d10
Minimum thickness = 150.00 mm Section 12.4 Ref. 2
Determine Maximum Allowable d50f for Filter
A50 = 28 Using Cisten-Ziems chart (Fig. 16.2) Ref. 2
d50f = 5.04 mm = A50(d50s)
OK, FILTER SUITABLE
197 Loudon Road, Suite 310
Concord, NH 03301
2. HEC-23: Bridge Scour & Stream Instability Countermeasures: Experience, Selection, & Design Guidance -
3rd Edition, Vol. I & II
T:\Projects\New Hampshire\Swanzey 23737 Winchester 23738\23737_23738\Computations\Filter Design\Granular\Filter Design_Riprap_Calcs_Swanzey 23737.xlsx HA-6
Job Swanzey 23737 Computed By TPL Date 11/20/2013
Description Sawyers Crossing over Ashuelot River Checked By FB Date 2/24/2014
197 Loudon Road, Suite 310
Concord, NH 03301
Determine Maximum Allowable d50R for Riprap directly on Filter
A50 = 10 Using Cisten-Ziems chart (Fig. 16.2) Ref. 2
d50R = 47.50 mm = A50(d50s)
NG, INTERMEDIATE FILTER REQUIRED
Determine Key Indices for Intermediate Filter Use NHDOT Spec 304.6 - Crushed Stone (Very Coarse)
d50 = 37.50 mm Section 304, Table 1 Ref. 3
d10 = 4.75 mm Section 304, Table 1 Ref. 3
d60 = 75.00 mm Section 304, Table 1 Ref. 3
Cu = 15.79 = d60/d10
Minimum thickness = 150.00 mm Section 12.4 Ref. 2
Determine Maximum Allowable d50f for Intermediate Filter
A50 = 32 Using Cisten-Ziems chart (Fig. 16.2) Ref. 2
d50f = 152.00 mm = A50(d50s)
OK, INTERMEDIATE FILTER SUITABLE
Determine Maximum Allowable d50R for Riprap directly on Intermediate Filter
A50 = 9 Using Cisten-Ziems chart (Fig. 16.2) Ref. 2
d50R = 337.50 mm = A50(d50s)
OK, NO ADDITIONAL INTERMEDIATE FILTER REQUIRED
Check Hydraulic Conductivity of Filter Layer
Base soil properties do not match types listed in Table 16.1 Ref. 2
Calculate estimated hydraulic conductivity of the base soil
Kozeny-Carman Equation Ks = (g/v)*5.556*10-3
[n3/(1-n)
2]*d10
2
gravitational accel, g = 9.81 m/s2
kinematic viscosity, v = 1.307E-06 m2
/s @ 50o
F
porosity, n = 0.8279 = 0.255 (1+ 0.83Cu)
Ks = 0.44950814 cm/s
Kfilter > 4.49508136 cm/s must be > 10Ks
T:\Projects\New Hampshire\Swanzey 23737 Winchester 23738\23737_23738\Computations\Filter Design\Granular\Filter Design_Riprap_Calcs_Swanzey 23737.xlsx HA-6
Job Swanzey 23737 Computed By TPL Date 11/20/2013
Description Sawyers Crossing over Ashuelot River Checked By FB Date 2/24/2014
197 Loudon Road, Suite 310
Concord, NH 03301
Calculate estimated hydraulic conductivity of the filter layer
porosity, n = 2.9359 = 0.255 (1+ 0.83Cu)
Kfilter = 63.4028334 cm/s must be > 10Ks OK
Calculate estimated hydraulic conductivity of the intermediate filter layer
porosity, n = 3.5968 = 0.255 (1+ 0.83Cu)
Kfilter_I = 649.723332 cm/s must be > Kfilter OK
T:\Projects\New Hampshire\Swanzey 23737 Winchester 23738\23737_23738\Computations\Filter Design\Granular\Filter Design_Riprap_Calcs_Swanzey 23737.xlsx HA-6
Job Swanzey 23737 Computed By TPL Date 8/29/2014
Description Sawyers Crossing over Ashuelot River Checked By RTG Date 9/4/2014
GRANULAR FILTER DESIGN for A-JACKS
References:
1. NHDOT River Bed Sample Sieve Test Results, October 18, 2013
3. NHDOT Standard Specs for Road & Bridge Construction, 2010
Note: A-Jacks require an uppermost filter layer: AJ-24 units
Required d50 = 50-75 mm Table 19.5 Ref. 2
Determine Key Indices for Base Soil
d50s = 0.18 mm Interp. Grain Dist Chart Ref. 1
d10s = 0.075 mm Ref. 1
d60s = 0.203 mm Ref. 1
Cu = 2.71 = d60/d10
Determine Key Indices for Uppermost Filter Layer Use NHDOT Item 585.3 - Stone Fill, Class C
d50 = 50.00 mm Section 585.2.1.3 Ref. 3
d15 = 37.50 mm Section 585.2.1.3 Ref. 3
d85 = 100.00 mm Section 585.2.1.3 Ref. 3
Cu = 2.67 = d85/d15
Determine Maximum Allowable d50R for Uppermost Filter Layer directly on Base Soil
A50 = 13 Using Cisten-Ziems chart (Fig. 16.2) Ref. 2
d50R = 2.34 mm = A50(d50s)
NG, INTERMEDIATE FILTER REQUIRED
Determine Key Indices for Filter Use NHDOT Spec 304.4 - Crushed Stone (Fine)
d50 = 4.75 mm Section 304, Table 1 Ref. 3
d10 = 1.50 mm Section 304, Table 1 Ref. 3
d60 = 19.00 mm Section 304, Table 1 Ref. 3
Cu = 12.67 = d60/d10
Minimum thickness = 150.00 mm Section 19.6 Ref. 2
Determine Maximum Allowable d50f for Filter
A50 = 28 Using Cisten-Ziems chart (Fig. 16.2) Ref. 2
d50f = 5.04 mm = A50(d50s)
OK, INTERMEDIATE FILTER SUITABLE
197 Loudon Road, Suite 310
Concord, NH 03301
2. HEC-23: Bridge Scour & Stream Instability Countermeasures: Experience, Selection, & Design Guidance -
3rd Edition, Vol. I & II
T:\Projects\New Hampshire\Swanzey 23737 Winchester 23738\23737_23738\Computations\Filter Design\Granular\Filter Design_AJacks_Calcs_Swanzey 23737.xlsx HA-6
Job Swanzey 23737 Computed By TPL Date 8/29/2014
Description Sawyers Crossing over Ashuelot River Checked By RTG Date 9/4/2014
197 Loudon Road, Suite 310
Concord, NH 03301
Determine Maximum Allowable d50R for Uppermost filter layer directly on Intermediate Filter
A50 = 11 Using Cisten-Ziems chart (Fig. 16.2) Ref. 2
d50R = 52.25 mm = A50(d50s)
OK, NO ADDITIONAL INTERMEDIATE FILTER REQUIRED
Check Hydraulic Conductivity of Filter Layer
Base soil properties do not match types listed in Table 16.1 Ref. 2
Calculate estimated hydraulic conductivity of the base soil
Kozeny-Carman Equation Ks = (g/v)*5.556*10-3
[n3/(1-n)
2]*d10
2
gravitational accel, g = 9.81 m/s2
kinematic viscosity, v = 1.307E-06 m2
/s @ 50o
F
porosity, n = 0.8279 = 0.255 (1+ 0.83Cu)
Ks = 0.44950814 cm/s
Kfilter > 4.49508136 cm/s must be > 10Ks
Calculate estimated hydraulic conductivity of the intermediate filter layer
porosity, n = 2.9359 = 0.255 (1+ 0.83Cu)
Kfilter = 63.4028334 cm/s must be > 10Ks OK
Calculate estimated hydraulic conductivity of the uppermost filter layer
porosity, n = 0.8194 = 0.255 (1+ 0.83Cu)
Kfilter_I = 98988.1331 cm/s must be > Kfilter OK
T:\Projects\New Hampshire\Swanzey 23737 Winchester 23738\23737_23738\Computations\Filter Design\Granular\Filter Design_AJacks_Calcs_Swanzey 23737.xlsx HA-6
NHDES Standard Dredge and Fill NHDOT
Swanzey 23737 over Ashuelot River
Exhibit H ‐ Photographs
Photo 1 Cresson Covered Bridge, view southeast. All photos June 12, 2015.
Photo 2 Sandbar downstream of center pier.
NHDES Standard Dredge and Fill NHDOT
Swanzey 23737 over Ashuelot River
Exhibit H ‐ Photographs
Photo 3 Center pier
Photo 4 View west from east bank of center pier and sandbar
NHDES Standard Dredge and Fill NHDOT
Swanzey 23737 over Ashuelot River
Exhibit H ‐ Photographs
Photo 5 View west
Photo 6 River substrate viewed from east bank, typical of area
NHDES Standard Dredge and Fill NHDOT
Swanzey 23737 over Ashuelot River
Exhibit H ‐ Photographs
Photo 7 River substrate, view from bridge looking upstream
Photo 8 Example of A‐Jacks installation at another site.
Image from http://www.conteches.com/products/erosion‐control/hard‐armor/a‐jacks.aspx. Accessed June 28, 2015.