Bear Creek Watershed-Scale Stormwater Management Plan Technical Workshop Wednesday, March 29, 2017 Participant Exercises - Considerations 1. Bear Creek Rural Areas Key Considerations • 83% of the watershed is rural lands, 45% of the rural area is developed at densities greater than rural zoning designations. • Most development occurred prior to any modern-day resource protection measures. • Health of the stream system has degraded over time. This includes: o increases in stream flow flashiness; o pockets of flooding; o loss of native riparian vegetation; o increased stream temperatures; o bacteria concentrations exceeding state standards, and increased loadings of other pollutants; and o instream habitat lack diversity and salmon populations are considered depressed and in decline. • The vast majority of parcels have already been developed. It’s projected that about 20% of the parcels in the study area will either be new development or re-develop that may trigger stormwater control measures in the next couple of decades; leaving retrofitting as the primary mechanism for restoration. • Public property – centralized, limited amounts of public lands, may be more expensive, far greater certainty of occurring. • BMP’s on privately held lands will be less expensive, may be less effective if not fully implemented, requires a large percentage of the land owners participate and takes longer to implement. There will be less certainty that BMPs: will be kept properly functioning, or continue to exist over time as ownership changes, public willingness to participate, and accepting limitations on alternative uses for that portion of land. • Above ground BMPs are less expensive, easier to maintain, most often single purpose use. • Below ground BMPs are more expensive, potentially harder to maintain, allow for alternative uses above ground (e.g., playgrounds, roads, parking lots). • BMPs types that address 1) Flow control, 2) Infiltration, 3) Water Quality, and 4) Habitat will all likely be needed. • All of the rural areas operate with onsite septic systems. • Most of the rural residents are on public water supply, very few use private drinking wells. FINAL 201-03-27 Participant Exercises - Considerations
Transcript
Bear Creek Watershed-Scale Stormwater Management Plan Technical Workshop
Wednesday, March 29, 2017
Participant Exercises - Considerations
1. Bear Creek Rural Areas
Key Considerations • 83% of the watershed is rural lands, 45% of the rural area is developed at densities greater than rural zoning designations. • Most development occurred prior to any modern-day resource protection measures. • Health of the stream system has degraded over time. This includes:
o increases in stream flow flashiness; o pockets of flooding; o loss of native riparian vegetation; o increased stream temperatures; o bacteria concentrations exceeding state standards, and increased loadings of other pollutants; and o instream habitat lack diversity and salmon populations are considered depressed and in decline.
• The vast majority of parcels have already been developed. It’s projected that about 20% of the parcels in the study area will either be new development or re-develop that may trigger stormwater control measures in the next couple of decades; leaving retrofitting as the primary mechanism for restoration.
• Public property – centralized, limited amounts of public lands, may be more expensive, far greater certainty of occurring. • BMP’s on privately held lands will be less expensive, may be less effective if not fully implemented, requires a large percentage of the land owners
participate and takes longer to implement. There will be less certainty that BMPs: will be kept properly functioning, or continue to exist over time as ownership changes, public willingness to participate, and accepting limitations on alternative uses for that portion of land.
• Above ground BMPs are less expensive, easier to maintain, most often single purpose use. • Below ground BMPs are more expensive, potentially harder to maintain, allow for alternative uses above ground (e.g., playgrounds, roads, parking lots). • BMPs types that address 1) Flow control, 2) Infiltration, 3) Water Quality, and 4) Habitat will all likely be needed. • All of the rural areas operate with onsite septic systems. • Most of the rural residents are on public water supply, very few use private drinking wells.
FINAL 201-03-27 Participant Exercises - Considerations
Buffer FenceChannel Restoration (e.g., re-meandering, channel adjustment, LWD placement, riparian planting)Floodplain, Wetland, and Floodplain Ponds Restoration, Connection, and CreationLarge Woody Debris Supplementation and In-stream StructuresNative Revegetation (non-trees)Off-channel, side-channel, and Tributary Restoration, Connection, and CreationRemoval of bank modificationsRiparian Forest BufferSediment Reduction (e.g., road restoration, agricultural treatments, sw strategies)
Tree Replanting Program, watershed wide
Evaluation Criteria
Water Quality Type Constructed BMPs
Habitat Type Constructed BMPs
Stream Flow Water Quality HabitatProblems
Bear Creek Watershed-Scale Stormwater Management Plan Technical Workshop
Wednesday, March 29, 2017
Definitions Sheet
Constructed BMPs Names Definitions
Access Control/Use Exclusion This practice involved keeping livestock out of grazing areas during times of the year when they are susceptible to water quality, soil and plant impacts.
Animal Waste Utilization Application of aged organic material to fields, at agronomic rates, during the growing season.
Basic Dispersion BMP Includes dispersion device (e.g. rock pad, splash block) and dedicated flow path of specified length. Flow path for basic dispersion may be over non-native vegetation and vary by dispersion device.
Bioretention BMP Pre-sized in KCSWDM to achieve LID Performance Standard for flow control based on till, outwash, and rainfall regions. Depth is 6" minimum to 12" maximum. Includes 18" of bioretention soil mixture over in situ soils. Underdrained designs not allowed w/o variance in KC. Requires 1 foot separation from bottom of BMP to seasonal high groundwater.
Bioswale Facility A bioswale is an open, gently sloped, vegetated channel designed for treatment of stormwater. Basic treatment. Buffer Fence Fencing used to keep livestock a specified distance away from a waterbody.
Detention Vault or Tank Underground storage structure with orifice, weir, etc. for controlled/metered release .
Full Dispersion (100 ft. forested flow path)
Target surfaces are dispersed into native vegetated areas. Fully dispersed surfaces are considered mitigated for flow control, water quality, and LID/BMP requirements. Total area dispersed (impervious and non native pervious) must be no more than 35% of site. Various dispersion devices (rock pads, gravel trenches, sheet flow) with limitations on amount of impervious surfaces tributary to each device. Flow path is subject to restrictions including slope, adjacency to hazard areas and septic systems. Applicable to both pollution generating and non pollution generating surfaces.
Full Infiltration BMP Use of gravel filled trenches, drywells, or ground surface depressions to fully and reliably infiltrate runoff into the ground. In situ soils must be coarse sands or cobbles or medium sands. Requires a minimum 1 foot separation to max seasonal groundwater from bottom of BMP.
Infiltration Pond Facility Open air (pond) infiltration facility.
Infiltration Vault or Tank Facility
Underground vaults or tanks that allow infiltration of stormwater. Infiltration tanks consist of underground pipe that has been perforated to allow detained stormwater to be infiltrated. Infiltration vaults consist of a bottomless concrete vault structure placed underground in native infiltrative soils.
Limited Infiltration BMP (dry well or trench)
Pre-sized in KCSWDM to achieve LID Performance Standard for flow control based on till, outwash, and rainfall regions. Requires pretreatment if mitigating pollution generating surfaces unless underlying soils meet soil suitability criteria for groundwater protection. Requires 1 foot separation from bottom of BMP to seasonal high groundwater.
Constructed BMPs (continued) FINAL 03-27-2017 Definitions Sheet
Names Definitions
Permeable Pavement BMP Asphalt, concrete, or pavers may be used. 6" sand treatment liner is allowed for pretreatment only for residential driveways serving 2 or less households. Otherwise, pollution generating permeable surfaces not allowed unless underlying soils meet soil suitability criteria for groundwater protection.
Prescribed Grazing A grazing plan that maintains a stubble height of at least 3 inches Rainwater Harvesting (Cistern,
rain barrel) Rain Barrel (small scale) and Cistern (larger scale) retention systems. Typically requires action to be emptied unless orificed for ongoing controlled release.
Reduced Impervious BMP Reduction in impervious surface below established norms must be assured through covenant and/or alternative design of impervious surfaces. For example: Restricted footprint ; Wheel strip driveways; minimum disturbance foundation, etc.
Riparian Forest Buffer A buffer area along a waterbody, planted with native trees and shrubs.
Sand Filter Facility Stormwater filters through a constructed sand bed with an underdrain system. Basic treatment for standard size and enhanced basic treatment for large sand filters.
Limited Infiltration BMP (dry well or trench)
Pre-sized in KCSWDM to achieve LID Performance Standard for flow control based on till, outwash, and rainfall regions. Requires pretreatment if mitigating pollution generating surfaces unless underlying soils meet soil suitability criteria for groundwater protection. Requires 1 foot separation from bottom of BMP to seasonal high groundwater.
Permeable Pavement BMP Asphalt, concrete, or pavers may be used. 6" sand treatment liner is allowed for pretreatment only for residential driveways serving 2 or less households. Otherwise, pollution generating permeable surfaces not allowed unless underlying soils meet soil suitability criteria for groundwater protection.
Prescribed Grazing A grazing plan that maintains a stubble height of at least 3 inches Rainwater Harvesting (Cistern,
rain barrel) Rain Barrel (small scale) and Cistern (larger scale) retention systems. Typically requires action to be emptied unless orificed for ongoing controlled release.
Reduced Impervious BMP Reduction in impervious surface below established norms must be assured through covenant and/or alternative design of impervious surfaces. Options include: Restricted footprint ; Wheel strip driveways; minimum disturbance foundation ; Open grid decking over pervious surface
Riparian Forest Buffer A buffer area along a waterbody, planted with native trees and shrubs.
Sand Filter Facility Stormwater filters through a constructed sand bed with an underdrain system. Basic treatment for standard size and enhanced basic treatment for large sand filters.
Stormwater Treatment Wetland Facility
Shallow man-made ponds that designed to treat stormwater through the biological processes associated with emergent aquatic plants. Considered to provide "enhanced basic treatment" e.g. 80% TSS removal plus 30% dissolved copper removal and >60% dissolved zinc removal. Can incorporate limited live storage.
Wet vault Facility Underground concrete vaults facility using dead storage to settle out pollutants. Used for basic (80% TSS removal goal).
Wetpond Facility Open air facility using dead storage to settle/remove pollutants. Basic treatment achieved. For large (1.5 x basic size) wet ponds, lake protection standard is achieved (50% Total Phosphorous removal goal).
FINAL 2019-03-27 Definitions Sheet
Background for Exercises - Programmatic BMPs
Base
flow
Flas
hine
ss
Floo
ding
(out
of
bank
)
Tem
pera
ture
F eca
ls
TSS
Met
als
BIBI
Fish
Wet
land
Ripa
rian
Vege
tatio
n
System-wide
applicationReadiness
Based on Audience Research
Effectiveness Cost
Adopt-a-Stream Foundation/ Streamkeeper
Bear Creek Watershed Network (to be created)Beaver Management (in development)KC Adopt a RoadKC Adopt-a-ParkKC Don't Drip and DriveKC Public Health Wastewater Program Natural Yard CarePet Waste (Poop and Scoop)Puget Sound Starts HereSalmon Watcher ProgramTake Back Your MedsWater TendersWaterWorks Grant Program
Acquisition and Protection (e.g. Conservation Easement)Copper Brake Pad RegulationCraft 3 - funding for OSSFarm Management PlanKC Land Conservation Work Plan
KCD Conservation Reserve Enhancement ProgramKCD Stream Stewards (Expand to Bear Creek)KCD Wetland Plan Cooperative
Regulatory Mechanisms for habitat regulationsStormwater Regulation (modify design manual requirements)
Public Outreach & Stewardship Type Programmatic BMPs
Regulatory & Government Action Type Programmatic BMPs
Evaluation CriteriaProblems
Stream Flow Water Quality Habitat
Bear Creek Watershed-Scale Stormwater Management Plan Technical Workshop
Wednesday, March 29, 2017
Definitions Sheet
Programmatic BMPs Names Definitions
Copper Brake Pad Regulation
WA Legislation requires brake pads sold or installed to have reduced levels of copper and other heavy metals due to claims that as brake pads wear down, copper and other metals are deposited on roadways where they are washed into streams and rivers.
Craft 3 - funding for OSS A nonprofit Community Development Financial Institution lender with a mission to strengthen economic, ecological and family resilience in Pacific Northwest communities by providing loans to businesses, nonprofits and individuals, including those without access to traditional financing. Focus is on Offsite septic systems.
Farm Management Plan
KC Adopt-a-Park Three or four volunteer work party events per year for brush clean-up, litter pick-up, tree planting, flower-bed weeding and/or planting, invasive weed removal, trail maintenance, monitoring restoration efforts, and many other potential projects.
KC Adopt a Road Litter reduction campaign designed to remove litter debris from unincorporated King County roads and improve the quality of the environment. The County provides guidance and equipment to foster safe and effective cleanups and the volunteers do the work of gathering the litter along designated roads.
KC Don't Drip and Drive Foster public understanding of stormwater, policies and plans to manage it, and ways we can all help. Resources can help determine if your car might be leaking, and if so, what you can do about it. They offer free inspection programs and workshops.
KC Land Conservation Work Plan King County’s conservation efforts are focused in five major categories, which taken together benefit nature and people.
KCD Wetland Plan Cooperative
The Wetland Plant Cooperative is a source of native plants and can provide assistance on designing and installing stream, wetland, estuarine and other habitat enhancement projects.
Mitigation Reserves Program - in-lieu fee
mitigation
When permitted projects will create unavoidable impacts to the environment, project sponsors must offset, or "mitigate" the environmental impacts associated with the project. The mitigation process includes avoiding and minimizing impacts as much as possible, and then making up for any unavoidable impacts through implementation of a mitigation project. Mitigation projects can occur on-site (at or near the place where the impact project occurs) or off-site. King County Code prioritizes on-site mitigation when it is ecologically feasible and likely to succeed long-term. However, if mitigation on or adjacent to the development site is impractical or won’t result in meaningful ecological benefit, off-site mitigation becomes an option under King County code and state and federal rules. Off-site mitigation options may include use of a mitigation bank, "permittee-responsible" mitigation, or in-lieu fee mitigation through the Mitigation Reserves Program.
Natural Yard Care SWD and WLRD have programs addressing natural yard care Pet Waste(Poop & Scoop) Offers ideas for pet owners to help keep streams, lakes and Puget Sound clean. FINAL 2019-03-27 Definitions Sheet
Programmatic BMPs (continued) Names Definitions
Public Transit Reduction Programs (Commute Trip
Reduction, Rideshare)
Law passed to improve air quality, reduce traffic congestion, and reduce the consumption of petroleum fuels through employer-based programs that encourage the use of alternatives to driving alone. Each city and county must reduce drive alone trips at major worksites by 10% by 2011.
Puget Sound Starts Here Public awareness campaign focuses on our connections to the Puget Sound. The goal of Puget Sound Starts Here is to raise awareness of how our everyday actions impact this place where we live, work and play.
Regulatory Mechanisms for habitat regulations TBD
Salmon Recovery Funding Board (SRFB) Grants
The State of WA Recreation and Conservation Office awards grants to King County annually to fund restoration of salmon habitat as well as acquisition of lands where habitat projects could be implemented to support salmon recovery efforts. Each year King County receives grants awarded by the SRFB to support salmon recovery efforts. Recent funding levels are roughly $400,000 annually; this amount may fluctuate depending on overall state budget and funding priorities.
Take Back Your Meds Helps people dispose of their unwanted medications. Large amounts of medicines go unused or are expired and how disposed makes a difference for our waters and our environment. Flushing drugs sends them directly into our waters.
Water Tenders
Grassroots organization dedicated to the protection and preservation of aquatic resources with a special focus on the Bear Creek Basin. Through educational outreach programs, they instill good stewardship ideals. Some efforts include: annual autumn docent programs during the salmon migration, educational kiosk installations, newsletters and community meetings.
WaterWorks Grant Program
KC Ordinance 18031 established grant award criteria and process for the WaterWorks Grant Program. Applicants can request funding from $25,000—$250,000 in support of sound investments in clean water and the community. WaterWorks provides funding to organizations for projects that create a benefit to or improvement of water quality within WTD’s service area and benefit its ratepayers. Non-profits, schools and educational institutions, cities, counties, tribes, and special purpose districts are eligible to apply, and partnerships are encouraged. Community involvement and support are key evaluation criteria, in addition to water quality benefits.
FINAL 2019-03-27 Definitions Sheet
2. Bear Creek Urban Areas Key Considerations:
• Portions of City of Redmond, City of Woodinville, and King County have urban areas. • City of Redmond (approx. 740 acres). Good infiltration are mostly located in the valley floors. • City of Woodinville (approx. 970 acres); much of the area mapping indicates good infiltration soils. • Unincorporated King County (approx. 1000 acres) is zoned residential and business/commercial. • Zoning greater than R-1 (more than one house per acre) has minimal pervious landscape, due to maximizing footprint of structures. • Problems are the same as in the rural areas except stream flows are flashier and metal concentrations are higher. • Over 75% of urban areas are developed, retrofitting is needed, some parcels are projected to be redeveloped, very few undeveloped parcels are
developable. • Implementing enough raingarden type of LID BMP (above ground) on private property may be difficult to achieve. • Implementation costs likely more expensive and less options to choose from because of feasibility. • Public outreach/stewardship programmatic BMPs (e.g., Poop and Scoop) will be less expensive and easier to implement, but greater uncertainty in
participation and effectiveness. • Regulatory/government action programmatic BMPs would be more effective (e.g., updating stormwater mitigation criteria), but harder to implement
and not very applicable for retroactive mitigation.
3. Plan Implementation Key Considerations:
• Requires multiple jurisdictions to collaborate. • To achieve targets for the specified metrics, it is likely all of the following are required:
o conventional ‘end of pipe’ stormwater infrastructure (e.g. ponds, tanks, vaults, sand filters, bioswales, etc.); o green infrastructure (e.g. bioretention, infiltration trenches, drywells, permeable pavements, injection wells); o habitat improvements; and/or o source control of pollutants.
• Implementation of the plan requires prioritization that considers: o Local resident willingness to see stormwater mitigation occur at a parcel level on their own property; and o Whether measurable improvements are desired sooner rather than later, and where to focus first.
• Programmatic BMPs are less quantifiable and less certain there will be full participation. • Should we spend resources beyond an estimated optimal cost-effectiveness?
o Should we switch to programmatic BMPs after we reach the “knee of the curve” even though the benefits from those type of BMPs is not readily quantifiable?
• How many years the implementation of the plan should be spread out with the understanding that the further in the future the objective is set, the less expensive per year it might be, but with less likely of success given that public and private core values may change over time.
FINAL 201-03-27 Participant Exercises - Considerations
Table #________ Bear Creek Watershed-Scale Stormwater Management Plan Technical Workshop Wednesday March 29, 2017
Participant Feedback Recording Sheet
We are interested in your input on how we prioritize work in this watershed. The following questions reflect the tradeoffs inherent in the selection of BMPs and the approach to plan implementation.
Please record your individual responses to the questions in the space provided below and with your table facilitator. If you have additional comments after the meeting, please email them to Jeff Burkey at [email protected] I. Rural Area
1. Constructed BMPs - What are your thoughts about where the emphasis should be placed for implementing BMPs - on public or private
lands?
2. Constructed BMPs - What are your thoughts about where we should place our emphasis - in above ground, land used for stormwater projects only or below ground projects where the surface of land can be used for something else?
FINAL 2017-03-27 Participant Feedback Recording Sheet Page 1 of 6
3. Constructed BMPs - Please put in rank order the importance of these evaluation criteria when selecting Constructed BMPs using 1-6, where 1 is least important and 6 is most important to you?
Cost Amount of Area Treated
Certainty and Ease of Maintenance
Longevity of BMPs
Public Perception and Acceptance
Executable/ Implementable
$$$$ $$$ $$ $
Some BMPs typically will mitigate multiple acres of disturbance. Whereas other BMPs commonly only treat 100's or thousands of square feet.
Whether the BMPs is easy to maintain, have a high degree of certainty that they will be maintained, and doesn't require maintenance more than once a year.
Whether BMPs are self-sustaining and last for decades if given proper maintenance or whether they are short lived.
Whether the BMPs are generally accepted by the public or does the BMP routinely get challenged.
What does it take to implement the BMP? Does it require public participation to be successful? Does it require regulatory adoption? Does it require land acquisition? Is there existing funding or no current funding?
4. Habitat: How should we prioritize habitat restoration efforts versus stormwater mitigation? Why is that important to you? Is it more
important to see habitat BMPs earlier, parallel or after the constructed stormwater BMPs?
FINAL 2017-03-27 Participant Feedback Recording Sheet Page 2 of 6
5. Programmatic BMPs - How would you prioritize the use of public outreach/stewardship versus regulatory/government action approaches to changing behaviors or practices that impact stream quality?
6. Programmatic BMPs - Please put in rank order the importance of these evaluation criteria when selecting Programmatic BMPs using 1-5, where 1 is least important and 5 is most important to you?
System-wide application Readiness Based on Audience Research Effectiveness Cost
Is the effort applied at upstream/system-wide
level (versus at downstream/site level)
Effort is already in place and ready to
use or is in a mature stage of
development
Was developed based on input from audiences
Does the program improved or changes awareness, attitude,
knowledge, or behavior?
$$$$ $$$ $$ $
FINAL 2017-03-27 Participant Feedback Recording Sheet Page 3 of 6
II. Urban Area 1. In a more urban environment with more expensive BMPs to implement, more constraints, and poorer stream health, please share your
thinking about the most effective approach? Programmatic, constructed, other creative ideas are welcome. Please share why.
III. Plan Implementation 1. How should we implement this plan? Please share your thoughts why it is your preferred approach. The below table shows some possible
approaches. If you have other suggestions for prioritizing or sequencing some other way, please share. Some examples:
Possible Approaches Some Pros and Cons
Watershed wide? Prioritize BMP construction based on modeled impact to the watershed overall; potentially most cost effective approach, more difficult to observe effectiveness and employ adaptive management as early as sub basin by sub basin approach; potentially more acceptable politically.
Sub-basin by sub- basin?
Construct BMPs/complete mitigation called for in the strategy in one sub-basin before moving on to the next—allows for earlier analysis/observation of effectiveness of mitigation strategy and allows adaptive management based on those results to be applied going forward.
• Worst First? Potentially provides cost effective opportunities to address many problems w/same mitigation/BMPs; prevents
hitting biological ‘tipping’ point where recovery becomes even more difficult. • Easiest First? Allows for earlier completion of and analysis/observation of effectiveness of mitigation strategy. • Upstream
First? Fixing upstream problems may contribute to improvements in downstream system not predicted by model; some mitigation types more likely to succeed by eliminating/fixing upstream flow/water quality problems first.
• Other sub-basin prioritization method or approach? Small group of key sub-basins?
Could include a sub-basin in each jurisdiction; or sub-basins selected to test strategy/BMP effectiveness vs problems—i.e. a temperature problem dominated basin, a fecal problem dominated sub-basin, a flow problem dominated sub-basin.
FINAL 2017-03-27 Participant Feedback Recording Sheet Page 4 of 6
2. The cost to meet the targets using constructed solutions will be significant. At some point in the future, water quality, flow, and/or BIBI
targets may be partially or mostly achieved after large expenditure/construction of BMPs. Modeling or actual results may predict diminishing returns (marginal improvements to meet target metrics) for further investment in BMP construction. How important is it to you that the targets identified in the Plan be achieved fully? At what point should other solutions/practices be considered?
3. Depending on how the BMPs are implemented, it may take decades before there will be any measurable improvements within Bear Creek.
a. What is an acceptable time horizon for achieving the targets? (example – 20 years, 50 years, 100 years?)
b. How long before you feel it would be important to see progress?
FINAL 2017-03-27 Participant Feedback Recording Sheet Page 5 of 6
4. Are there other issues, concerns, questions you may have about the Bear Creek Watershed scale Stormwater Management Plan?
Optional: Provide your name or organization here.
Thanks so much for your participation and comments!
FINAL 2017-03-27 Participant Feedback Recording Sheet Page 6 of 6
Background
Bear Creek Watershed-Scale Stormwater Management Plan Technical Workshop Materials 1
DRAFT 03-22-2017
2 DRAFT 03-22-2017
3 DRAFT 03-22-2017
4 DRAFT 03-22-2017
Current Conditions Summary
Bear Creek Watershed-Scale Stormwater Management Plan Technical Workshop Materials 5
Cottage Lake Creek Moderate-higher quality Pool quality/quantity at risk More LWD but still below PFC* Upper Bear Creek Higher quality habitats LWD and pool quantity/quality below PFC* Lower Bear Creek Low-moderate habitat quality Poor LWD volume and frequency Loss of channel complexity and floodplain connectivity * PFC (Properly functioning conditions)
Juvenile salmon use a variety of habitats in the Bear Creek Watershed Habitat use varies by month and sub-basin area
8 DRAFT 03-22-2017
Water Quality
Some water quality improvement, some water quality degradation.
Basin Plan can identify project solutions for decreasing human health risk (bacteria) and protecting aquatic life (temperature, dissolved oxygen, TSS).
9 DRAFT 03-22-2017
Stream Macroinvertebrate Diversity Slight increase in B-IBI statewide over 20 years. But still not at desired levels B-IBI strongly influence by
urbanization. Many sites in Study Area have declining B-IBI. Flashiness increases with urbanization and deteriorates B-IBI Reducing flashiness may contribute to improved B-IBI in the
future.
10 DRAFT 03-22-2017
Wetlands Assessment
Wetlands are important because of their role in the watershed’s hydrology & ecology.
Approx. 330 mapped wetlands in watershed & likely many more unmapped wetlands.
Change analysis shows loss to development. 20% of baseline wetlands were visibly altered since 1981-1990
Limitations of available data likely leads to under-reporting of loss.
