1 / 21

Greening the Region Using Stormwater Infrastructure

Greening the Region Using Stormwater Infrastructure. May 7, 2014 Jim Simmonds King County Water and Land Resources Division Jim.Simmonds@kingcounty.gov. Stormwater Paradigm. Parcels Built Before Stormwater Controls Required. About three-fourths of urban lands lack stormwater facilities.

sharne
Download Presentation

Greening the Region Using Stormwater Infrastructure

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Greening the Region Using Stormwater Infrastructure May 7, 2014 Jim Simmonds King County Water and Land Resources Division Jim.Simmonds@kingcounty.gov

  2. Stormwater Paradigm

  3. Parcels Built Before Stormwater Controls Required About three-fourths of urban lands lack stormwater facilities

  4. Check Dams Stormwater Retrofit Examples Bioswales Cisterns Ponds Pervious Pavement Green Roofs Rain Gardens

  5. Estimated Stormwater Needs • $3B - $15B for treatment in Puget Sound • Capital costs, no O&M, no land costs • $1.4B for Juanita Creek basin (7 sq miles) • Full lifecycle cost • $1.1B for 64 small basins in unincorporated King County • Full lifecycle costs

  6. Stormwater Retrofit Planning for WRIA 9 • $1M grant from EPA, $335K match • 4 years • Model stormwater retrofit needs in WRIA 9 • Work with stakeholders • Present retrofit options analysis to WRIA 9 Watershed Ecosystem Forum • Extrapolate cost estimates to all Puget Sound

  7. Project Benefits • Planning-level estimate of facility and funding needs • Cost vs stream improvement • Demonstrate use of modeling tools • Influence capital project planning • Influence future NPDES permits • Influence discussion on new funding

  8. Approach • Gather geospatial data about • existing stormwater facilities, soil, precipitation patterns, slope, impervious area, development type, land costs, stream channels • Conduct hydrologic modeling • Model hydrologic improvements with stormwater facilities

  9. Future Development 2007 Satellite-Derived Land Use (UW 2007) 2040 Simulated Land Use (Alberti 2009)

  10. SUSTAIN: System for Urban Stormwater Treatment and INtegration

  11. Modeling Approach • Study area: 278 mi2, 446 catchments • Model 135 hypothetical 100-acre catchments representing combinations of: • 5 generic land uses • 3 soil types • 2 slopes • 3 precipitation zones • 2 land costs

  12. SUSTAIN Optimization Target: Reduce Stream Flashiness High Pulse Count: Number of times mean daily flows ≥ high-flow threshold set at 2 X long-term mean daily flow rate

  13. High Pulse Count and Biology

  14. Addressing Redevelopment • Redevelopment improves stormwater management • Nearly ½ of project area to have new or re development by 2040 • More expected beyond 2040 • Decreases estimated need

  15. Addressing Climate Change • Three approaches for assessing impacts • Analysis of precipitation patterns for downscaled global climate model output • Impacts of climate change on hypothetical pond sizing • Impacts of climate change on high pulse count in hypothetical basin • Likely need about 10% more flow control, but model variability is large

  16. 2040 Potential B-IBI Scores No Stormwater Management Full Stormwater Management

  17. Policy and Planning Horizon are Everything • How stringent are stormwater requirements for redevelopment? • How aggressively do public programs build facilities? • How long in the future do we aim for success?

  18. What If? • Assume new and redevelopment builds on-site facilities and developers contributes funds to build off-site facilities (ponds) • Assume public funds used to build everything else • Assume all stormwater facilities built within either 30 years

  19. Annual Public Costs

  20. The Big Questions • How quickly do we want to improve stream flows and water quality? • To what degree do we want to improve stream flows and water quality? • Where does capital funding come from? • Where does operating funding come from?

  21. Project Team • Don Robinett, SeaTac • Ben Parrish, Covington • Chris Thorn, Auburn • Jeff, Burkey, Curtis DeGasperi, David Funke, Larry Jones, Chris Knudson, Beth leDoux, Doug Navetski, Elissa Ostergaard, Giles Pettifor, Dan Smith, Allison Vasallo, Mark Wilgus, Olivia Wright, King County • Rich Horner, ErkanIstanbullouglu, UW • Ed O’Brien, Mindy Roberts, Ecology • Dino Marshalonis, Michelle Wilcox, EPA • Tamie Kellogg, Kellogg Consulting

More Related