Swan Creek Urban BMP Inventory and Assessment Jeff Grabarkiewicz, Kari Gerwin, Ann-Drea Hensley TMACOG, Lucas SWCD/Engineers, and Partners
Presentation Outline Project Background Methods Inventory Desktop Analysis Initial Results Desktop reduction Ranking and criteria Field visits Outcomes
Project Background Project began as a grant application in 2010 Original idea was to inventory and assess stormwater ponds in four Swan Creek subdrainages and retrofit three to five sites GOAL: Improve Swan Ck. water quality and downstream channel stability Funded in 2011 through Lake Erie Protection Fund
Mapping: TMACOG Project Background
Project Background: Why These Watersheds? Resources Sources of Impairment (Swan Creek TMDL) - Swan Wolf Creek, Creek: TMDL Urban runoff, storm sewers, surface/parking runoff - Heilman Ditch-Swan Creek: Urban and industrial runoff - Lower Blue Creek: Urban runoff and storm sewers - Gale Run-Swan Creek: Unspecified
Project Background Question: How do we establish a pool of locations that maximize retrofit benefits in these four subwatersheds? (on a budget)
Presentation Outline Project Background Methods Inventory Desktop Analysis Initial Results Desktop reduction Ranking and criteria Field Visits Outcomes
Methods Reviewed retrofit guides Formed a technical team TMACOG, Lucas SWCD, Village of Whitehouse, Springfield Township, Lucas County Engineer s Office, City of Toledo, Ohio EPA, and NRCS
Methods: Inventory Establish retrofit possibilities Focused on stormwater ponds, bioretention, culverts, parking lots, outfalls, rooftop retrofit GIS (Geographic Information Systems) Data from Lucas County Engineer s Office, Auditors Office, and Penta Career Center Layers- storm sewer outfalls, culverts, sw ponds, parking lots Aerial photos, roads, utilities, streams, wetlands, etc.
Methods: Desktop Analysis Suitability Mapping for BMPs For some BMPs we applied an initial suitability filter Bioretention Pervious pavement Culverts and Outfalls
Methods: Desktop Analysis Developed suitability criteria for individual BMPs PDA s/pca s Imperviousness Residential/commercial/industrial areas Well-draining soils Access to streets Sewered areas Parks Slope Zoning Floodplains Sewered areas Parks Slope Zoning Floodplains Public lands Groundwater Pollution Potential Areas (avoid for infiltration practices)
Methods: Desktop Analysis Example: Bioretention Cells GIS Layers for Raster Calculator Example: Bioretention Criteria Areas (Suitability Map)
Presentation Outline Project Background Methods Inventory Desktop analysis Initial Results Desktop reduction Ranking and criteria Field visits Outcomes
Initial Results After the inventory and suitability analysis we had an initial pool of possibilities: 130 stormwater ponds 357 parking lots 33 cul-de-sacs 19 culverts 6 outfalls Need to eliminate sites to reduce the pool
Desktop Reduction: Sit SW Ponds 130 stormwater ponds Went through one-by-one and ranked ponds low or medium if- Extended detention/extended retention Possessed wetland features
Desktop Reduction: Sit Parking Lots 357 parking lots
Desktop Reduction Ultimately, every potential retrofit location was looked at by a team member All locations that received a high ranking proceeded to the final round We reduced our pool from 624 sites to 133 sites
Field Visits and Ranking All 133 sites were visited and if deemed suitable, were then ranked
Ranking Volume of water (required drainage areas) Cost (Green Values National SW calculator) Access Impervious area treated Position relative to impairments (IBI) Lasting Impact (scored 1-5 or 10-30 total)
Outcomes 87 final sites made it through the desktop reduction/field check/ranking Top 14 retrofit sites 1. Stormwater pond, City of Toledo, 1.5 acres 2. Outlet Diversion, City of Toledo, 1.3 acres 3. Parking lot, City of Maumee, 0.3 acres 4. Parking lot, City of Toledo, 1.8 acres
Outcomes: Mapping Volume of water (required drainage areas) Cost (used National SW calculator) Access Impervious area treated Position relative to impairments (IBI) Lasting Impact (scored 1-5 or 10-30 total)
Deliverables GIS-based maps for major jurisdictions Retained all sites (low, med, high) Spreadsheet of sites with all pertinent data Project Poster and Presentation Web content GIS-based inventory of existing green infrastructure GIS database of feasible retrofits for existing stormwater practices Database User s Manual
Acknowledgements Lake Erie Protection Fund Technical Team: Lucas County Engineer s Office, USDA-NRCS, City of Toledo, Springfield Township, Village of Whitehouse, Ohio EPA, LSWCD, TMACOG Penta Career Center, Cuyahoga SWCD TMACOG staff: Ann-Drea Hensley, Kari Gerwin, and Kurt Erichsen