Low Impact Development -- Better Streets for Water Quality

1. Low Impact Development -- Better Streets for Water Quality Sustainability Collaborative August 4, 2004 Chris Eaton, AICP, Angelo Eaton & Associates

2. Presentation Overview • Green Streets, Green Roofs, Green Parks • why, what, how • Low Impact Development - State of the Art in the Pacific Northwest • Buildings/roofs • Parks • Parking Lots • Streets • Samples of built projects, standards and guidelines • Resources

3. Why work to solve issues? • Environmental Benefits • Infiltrate storm water close to source mirrors the natural system • Reduces runoff • Reduces detention requirements • Improves groundwater recharge • Current water quality treatment may not adequately address pollution issues such as temperature • Pending water quality rules (TMDLs) may increase standards

4. Why work to solve issues? • Improve Quality of Life • Additional street trees • Provides more “livable streets” • Public has more awareness of water quality • Salmon are happier with cooler water

5. Why is Low Impact Development Important?

6. What is Low Impact Development? • Low Impact Development (LID) seeks to reduce impacts of built environment: • Emulate natural hydrology • Recharge ground water • Zero runoff • Maximize Infiltration • Minimize Impervious Surface • Treat runoff at the source • Handle first ½” rainfall with infiltration measures • Smaller parking areas and streets/driveway areas

7. How to achieve LID for water quality • Pervious driveways and sidewalks • Pervious pavement – overflow parking • Collect roof runoff • Rain Garden (bio-retention) • Swales and strips (bio-filtration) • Hot Spot water quality treatment

8. Alternative Storm Water Management in Oregon and Washington • Low Impact Development related to water quality and storm water • Buildings/roofs • Parks • Parking Lots • Streets • Tualatin Basin Alternative Storm Water Manual • Samples of built projects

9. Samples of new designs - Roofs • Buckman Terrace, Portland, OR

10. Samples of new designs - Roofs • Convention Center, Scupper and Rain Garden, Portland, OR

11. Samples of OLD designs - Roofs • Marble Scupper Trajan Forum, Roma, Italy (early 2nd century A.D.)

12. Samples of new designs - Parks • Ralph Stanley Park, CascadeStation, Portland, OR

13. Samples of new designs – Parking Lots • Water Quality Swale, Parking Lot C, Tualatin Commons, Tualatin, OR

14. Samples of new designs - Parking Lots • Pervious Pavers on overflow parking area, Tualatin Police Building, Tualatin, OR

15. Samples of new designs - Streets • SEA Streets, NW 2nd Ave (between 117th and 120th) Greenwood Neighborhood, Seattle, WA

16. Samples of new designs - Streets • Eagle Landing, Clackamas, Oregon, 2004

17. Why are streets important? • Typical urban street standards assume a piped infrastructure with raised curbs • Current Storm water standards require new streets/development to meet water quality and detention standards. • In Tualatin Basin, these standards generally based on Clean Water Services

18. Why are streets important? • There are new prototypes being developed (or “reinvented”) for use for both streets and parking areas

19. Water Quality Model Street Standards • Goal: work with local government staff to develop street/stormwater design criteria that would be approved through the land division process.

20. Tualatin Valley Water Quality Endowment Fund Project • Tualatin Basin Alternative Storm water Manual • Follow-up to Audubon project “Stormwater Pavement Impacts Reduction (SPIR) project • 10 Tualatin Basin local governments • Clean Water Services • Getting “Green Street” concepts through the permit process

21. Alternative Storm Water Manual • This will make it possible for new development or new road projects to incorporate “green street” features without needing a variance or special process.

22. Alternative Storm Water Manual • Approach • Meet or exceed the minimum standards for • Road right –of-way widths; • Stormwater systems; • Detention, • Water quality; and • Pollution reduction requirements. • Swale design follows design parameters illustrated and described in this manual. • Swale vegetation shall be consistent with CWS standards. • Determine pre and post development stormwater runoff quantities. • Analyze the down-stream capacity. • Provide detention that meets or exceeds the level required. Size the facilities accordingly. • Plant additional street trees of certain type

23. Alternative Storm Water Manual • If infiltration is proposed, provide facility sizing information including soil percolation rates. • Public Streets - City or County road design standards for pavement width and ROW width will apply. Curbless streets or alternatives curbs as illustrated in this manual are acceptable and shall not require a road variance. • Narrower pavement widths are encouraged, but would be an exception to those standards and will require a special variance. • Private “green streets” are acceptable if they meet the criteria and standards outlined in this manual. • Street Classification - The Green Street approach is best suited to Local Streets, although could also be applied to collector and arterial streets. • Maintenance responsibility for Green Street stormwater facilities must be established.

24. Alternative Storm Water Manual

25. Alternative Storm Water Manual

26. Alternative Storm Water Manual

27. Alternative Storm Water Manual

28. Implementation Issues • Maintenance is an unknown for local governments • Cost and equipment • Public education • Engineering studies on long term projects are underway, but not final • Physical limitations (slope and soil constraints) • DEQ Underground Injection Control (UIC) Program • UIC program does NOT apply to all swales • “Rule authorized” approach is not burdensome • Amount of land in right-of-way • Developer perception is that approval of new approaches may be difficult

29. Built Projects, Standards and Guidelines • Important to show local officials, professionals, and investors built examples • Understand that some LID looks “different” • Public education

30. Infiltration Planter Storm water Manual, Portland Bureau of Environmental Services, Portland, Oregon, 2002

31. Downspout Storm water Manual, Portland Bureau of Environmental Services, Portland, Oregon, 2002

32. Curbless Parking Lot Clean Water Services Water Quality Laboratory, Hillsboro, Oregon, 2001

33. Curbless Parking Lot & Swale Clean Water Services Water Quality Laboratory, Hillsboro, Oregon 2001

34. Swale Clean Water Services Water Quality Laboratory, Hillsboro, Oregon, 2001

35. Porous Pavement Tualatin Police Training Facility, Tualatin, Oregon, 2001

36. Downspout Storm water Manual, Portland Bureau of Environmental Services, Portland, Oregon, 2002

37. Parking Lot Island & Wheel-Stop Weepholes Portland Community College Annex, Portland, Oregon, 2001

38. Wheel-Stop Weephole Portland Community College Annex, Portland, Oregon, 2001

39. Parking Lot Island Swale & Pedestrian Connection OMSI, Portland, Oregon, 2001

40. Weep hole Needing Maintenance Reed College, Portland, Oregon, 2001

41. Local Street with Swales Metro, Green Streets Manual, 2001

42. Local Treewell Metro, Green Streets Manual, 2001

43. Urban Treewell Metro, Green Streets Manual, 2001

44. Resources • Metro Greenstreets, Innovative Solutions for Stormwater & Stream Crossing, Metro Handbooks, June 2002, www.metro-region.org • SEA Streets, City of Seattle Conservation and Environment website, June 2002, www.seattle.gov/util/seastreets • City of Portland, Bureau of Environmental Services,http://www.cleanrivers-pdx.org/tech_resources/2002_swmm.htm • Oregon Department of Environmental Quality (DEQ), http://www.deq.state.or.us/wq/ • City of Vancouver, BChttp://www.city.vancouver.bc.ca/engsvcs/streets/greenstreets/

45. James Taylor Chair in Landscape and Livable Environments, Patrick Condon