High Point Natural Drainage System (NDS) Project

Because of its size and its relationship to Longfellow Creek, the redevelopment of the High Point neighborhood in West Seattle offered Seattle Public Utilities (SPU) a unique opportunity to implement a large scale natural drainage system in an urban environment, where it could make a real difference. High Point features the largest natural drainage project that the City has undertaken, and the first time that a natural drainage strategy of this scale has been used in such a high density urban setting.

Features and Benefits 

Designed in partnership with Seattle Housing Authority, this natural drainage system treats about 10 percent of the watershed feeding Longfellow Creek – one of Seattle’s priority watersheds.

The natural drainage system at High Point mimics nature in many ways, from using swales to capture and naturally filter stormwater to open, landscaped ponds and small wetland ponds to hold stormwater overflow. In short, High Point processes water just like a forest meadow.

High Point serves as an exemplary model for other large-scale developments and the potential to integrate green infrastructure, both locally and nationally. Take a virtual tour of the High Point Natural Drainage System.

Location

The High Point NDS is part of the High Point Redevelopment, which covers 34 blocks from 35th Ave SW to High Point Drive SW and SW Juneau St. to SW Myrtle St.

Construction Schedule

Construction of the first phase of the High Point NDS was completed in the fall of 2005. The first phase is bounded on the north and south by SW Juneau St. and SW Morgan St., and on the west and east by 35th Ave SW and High Point Drive SW. The second phase of construction was completed in 2009.

SPU began monitoring the first phase of the High Point natural drainage system in January of 2007.

Project Resources

• Low Impact Development Practices (PDF)
• Stormwater Flow Paths (PDF)
• High Point NDS Phase 1 (PDF)
• High Point NDS Phase 2 (PDF)
• Street Section Details (PDF)
• Roadway Detail (PDF)
• Drainage Details (PDF)
• Sidewalk Detail (PDF)
• Conformance Specs Swale (PDF)
• Cross Section with Utilities (PDF)
• Conformance Specs Pervious Pavement (PDF)