Longfellow Creek Natural Drainage System (NDS)

What & Why 

Seattle Public Utilities (SPU) will construct natural drainage systems (NDS) at 3 sites in the Longfellow Creek basin. NDS consist of shallow depressions in the public right-of-way, or "planter strip," filled with deep-rooted plants and spongy soils that temporarily hold and clean polluted stormwater from streets and sidewalks before the stormwater enters our waterways.

Natural drainage systems offer multiple community benefits, including:

  • Greener, more attractive neighborhoods
  • Lower risk of flooding
  • Healthier creek ecosystems
  • Calmer traffic patterns
  • And more

Seattle Department of Transportation is partnering with SPU on this project to provide pedestrian improvements at most sites, and this project is funded in part by the Levy to Move Seattle. 

The project FAQ contains more information.

What's happening now?

The team has completed our technical analysis of potential sites for the Longfellow Creek NDS project and selected sites that will move into the design phase. We selected sites based on a variety of factors that included community input, recurring drainage and flooding issues, existing soil conditions, and availability of off-street parking. Selected sites can be viewed on this map.

Selected Sites for Design:

  • 24th Ave SW between SW Thistle St and SW Barton St
  • Sylvan Triangle (Sylvan Way SW between SW Orchard St and Delridge Way SW)
  • 24th Ave SW and SW Kenyon St

Throughout 2019 and 2020, we will:

  • Design the natural drainage systems and pathway improvements
  • Continue to engage with residents, businesses, and community organizations around individual sites

If you're interested in learning more and finding out about upcoming community engagement events, please sign up for project updates.

Project goals and benefits

This project will improve water quality in Longfellow Creek, as well as improve stormwater drainage, slow down traffic, provide pedestrian improvements, and beautify streets.

The project will also help the City of Seattle achieve its goal of managing 700 million gallons of stormwater runoff using green infrastructure by 2025.

Project Documents