Pacific Northwest Green Street Pilot Projects, What Have We Learned?

Over the last several years, jurisdictions around the Pacific Northwest have been on a quest to find better and more sustainable techniques to manage stormwater runoff from street surfaces. Motivations for doing this consist of many things, including but not limited to the downgraded condition of our urban streams and waterways, the Federal Clean Water Act and subsequent NPDES (National Pollution Discharge Elimination System) MS4 permit requirements, TMDLs (Total Maximum Daily Loads) placed on waterways, the Safe Drinking Water Act and subsequent regulations on the injection of stormwater into the ground, and combined sewer system capacity deficiencies.Around ten years ago, jurisdictions in Oregon and Washington began experimenting with “Green Street” designs that reduce the negative effects of stormwater runoff by lowering the amount of impervious surface in the street section, or retaining and infiltrating stormwater in rain gardens, swales, or planters within the street right-of-way. Many pilot projects have been constructed and monitored, allowing us to acquire information on performance (flow rate and volume and pollution reduction), maintenance needs, public perception, ancillary benefits, and costs. A collaborative sharing of information has taken place, including a Green Street Summit between Vancouver British Columbia, Seattle, and Portland, which has quickly furthered progress.Today our streetscapes our changing before our eyes, as Green Street construction has become mandatory for new development in Portland and around the region. The market is further driving Green Street construction, as many of the techniques have proven to be more cost-effective than traditional designs.This presentation will highlight 13 Green Street pilot projects from around the Pacific Northwest over the last 10 years in chronological order, discussing lessons learned along the way. Projects include:Seattle Public Utilities SEA (Street Edge Alternatives) ProjectsN Leadbetter Road in PortlandNE 35th & Siskiyou in PortlandSE Ankeny in PortlandSE 20th & Division (New Seasons) in PortlandSW 12th & Montgomery at PSU in downtown PortlandWestmoreland Porous Pavement Pilot Project in PortlandN Gay Avenue Porous Pavement Pilot Project in PortlandNew Columbia in PortlandNE Fremont in PortlandSE 21st & Tibbetts (Peoples Co-op) in PortlandSE Yamhill in GreshamHigh Point in Seattle