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HomeMy WebLinkAboutStormwater Management Action Plan PP SupplementalStormwater Management Action plan (SMAP) Stormwater Management Action plan (SMAP) June 27, 2022 Background City is required to do a Stormwater Management Action Plan (SMAP) per the NPDES Phase II Stormwater Permit – Focus on Water Quality SMAP involves: Delineating watersheds Analyzing water quality data in these watersheds Prioritizing a watershed Picking a subbasin within the priority watershed to focus on for water quality measures Watershed Prioritization - Overview Watershed Prioritization based on: Fish Habitat Flow Water Quality Land Use Environmental Justice Watershed Prioritization - Fish Habitat Vegetated Stream Buffers Fish Barriers Watershed Prioritization - Flow Flow Control Facilities Watershed Prioritization - Water Quality Fairweather Creek Water Quality Watershed Prioritization - Land Use Vacant Land Watershed Prioritization - Environmental Justice Income Regions Watershed Prioritization - Matrix Watershed Prioritization - Matrix Fairweather Creek Basin = Priority Watershed Next Step – Choose a Subbasin Goals Selection Process (things to think about) Potential future projects/policies Upcoming required actions Next Steps Subbasin Discussion Northern Subbasins Fairweather Creek Subbasins Southern Subbasins Subbasin Selection – Goals Protect Change land use to preserve an area Restore Retrofit an area to provide water quality treatment -Structural Means -Non-Structural Means Subbasin Selection – Potential Actions Non-Structural (Policies/Activities): Source tracking study to see what pollutants are entering streams Public education Require developers to provide ‘enhanced’ treatment More frequent illicit discharge/spill inspections(i.e. catch basin inspections) Prioritize inspections of businesses for their stormwater practices Prioritize maintenance of city owned stormwater facilities Prioritize street sweeping / catch basin cleaning Subbasin Selection – Potential Actions Structural: Retrofit existing flow control/water quality facility (detention pond) Install new water quality facility (proprietary, possibly w/ future road/utility projects) Permeable pavement Modify ditches/biofiltration swales ‘Road diet’ – reduce impervious surfaces Install tree canopy over stream Also includes property acquisition for future facilities Subbasin Selection – What’s Coming Besides SMAP, City will also be required to do “Structural Stormwater Controls” (Projects that reduce pollutants or affect hydrology downstream) Counties/Large Cities doing these now Beginning 2024 (next NPDES Ph. II Permit cycle) Possibly choose SMAP subbasin knowing that these types of projects will be coming Each project = points; City needs X amount of points in the permit cycle Subbasin Selection – What’s Coming Current Relative Structural Stormwater Controls Point System: (subject to change) Points New/Retrofit flow control facility (detention) 1.0 In a known flooded area</ 1.5 New/Retrofit water quality facility 1.0 In a known water quality problem area</ 1.5 WQ provides enhanced/phosphorus treatment 2.0 Meets WQ standards (not just a retrofit project) < 2.5 Low Impact Development (LID) (i.e. rain garden) 1.5 Property acquisition 0.5 Maintenance (>$25k, miles swept or pipes cleaned) 0.25 Points Restoration of riparian buffer 0.35 Restoration of forest cover 0.25 Floodplain reconnection 0.10 Permanent removal of impervious surface 1.0 Points get multiplied by area served Currently counties/large cities have to collect 300 points (up to 75 points (or 25%) can be maintenance related) Subbasin Selection – Next Steps Recap Chose Fairweather Creek Watershed Talked goals for subbasin (protect or restore) Discussed possible future project types (structural / non-structural) Time to pick a subbasin (Ecology recommended 400 - 600 acres) By June 30th, only need to choose a subbasin (not projects)(per permit) Allow other interested parties (Tribes, Public, Natural Resource Agencies, etc.)to comment on selected subbasin. By March 2023, SMAP written to include subbasin, projects, costs, schedule and implementation plan. Subbasin Selection – Next steps Recommend selecting flow control/water quality projects that will meet the future permit (structural stormwater control projects) Retrofit Detention pond New Proprietary WQ vault/filter Projects selected will likely need to be constructed (In 2024+) Set realistic budget (possible Ecology grants) Realize realistic construction opportunities Combine w/ future road/utility projects? Subbasin Discussion Subbasin Selection Discussion Recommend Entire Fairweather Creek Watershed(Potential Projects Shown) Install new WQ Treatment Vault Potential Expansion of Existing Pond Potential Tree Canopy around Pond Creek listed on State list for impaired waterbodies ‘End of pipe’ types of facilities before discharging to the creek Potential Tree Canopy Opportunities