Longfellow Natural Drainage Systems

Review Status

On November 1, 2018, we reviewed the concept phase (30% phase) for the Longfellow Natural Drainage Systems project. At this meeting we approved the concept phase with several recommendations.

Project Description

Seattle Public Utilities (SPU) plans to improve the water quality within the region by preventing roughly 15,000 tons of pollutants from entering creeks within each of the City's three largest urban watersheds.  SPU will partner with Seattle Department of Transportation (SDOT) and other local agencies, community organizations, and private developers to construct bioretention systems within city rights-of-way (ROW).  The plan calls for the creation of four miles of bioretention systems by 2025 to help treat runoff from 44 acres, a minimum of 24 acres of which is located within the ROW.

As part of this plan to improve water quality, reduce flooding, and increase partnerships between departments and organizations, SPU has identified four project sites to implement natural drainage systems within the Longfellow Creek Watershed.  The project sites include:

  • Kenyon and 24th Ave SW
  • 24th Ave SW between Barton St SW and Thistle St SW
  • Sylvan Triangle
  • 29th Ave SW below Barton St SW

Natural drainage design features will include vegetation to clean pollutants and reduce flooding, new pathways, lighting, street trees, and reduced road widths.

November 1, 2018

Seattle Design Commission

Address: 600 4th Avenue, 5th Floor, Seattle, WA, 98124
Mailing Address: P.O. Box 94788, Seattle, WA, 98124-7088
Phone: (206) 684-0435

The Seattle Design Commission advises the Mayor, City Council, and City departments on the design of capital improvements and other projects and policies that shape Seattle's public realm.