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Ultra-Urban Stormwater Research Facility

WSDOT and its partners have cooperatively operated an ultra-urban stormwater research facility since 1996 . This test site receives urban stormwater from a heavily traveled section of an interstate highway within the City of Seattle (ultra-high traffic volume > average daily traffic (ADT) of 200,000 vehicles). The system collects highway runoff from one end of a bridge, and uses splitter pipes to route the flow to four test bays.

Photo Looking Down on Lake Union Stormwater Research Facility
Looking down onto the Lake Union Ship Canal Stormwater Research Facility

The drainage basin covers approximately 31.6 acres, with 22.7 acres of pavement and 8.9 acres of roadside landscaping. The WSDOT stormwater collection system for the basin is separate from the City of Seattle's stormwater system for the adjoining neighborhoods and streets.

Photo of a Flow Splitter at the Lake Union Stormwater Research Facility
The facility diverts road runoff through two sets of flow splitters, four gate valves, and into four test bays.

Photo of Detail Splitter looking down onto the Lake Union Ship Canal Stormwaer Research Facility Photo of a Gate Valve at the Lake Union Ship Canal Research Facility
Detail of flow splitter at the Ship canal Research Facility Gate valve leading to test bay at Ship Canal Research Facility


Stormwater equipment vendors who have participated in the project so far include:

  • Stormwater Management, Inc.
  • AquaShield, Inc.
  • Jensen Precast
  • BaySaver, Inc.

This project was initiated because of the sparse information on the effectiveness and maintenance requirements of "emerging", "proprietary", and "ultra-urban" stormwater treatment technologies.

  • Demand for technologies in highly urban areas 
  • Information needed for decision making
  • Highway Specific Data 
  • Stormwater concerns specific to highways
  • National audience for evaluation 
  • Develop a facility and program to allow public agencies to verify the performance of commercially available vault-contained BMPs
  • Provide proprietors a cost-effective means to demonstrate their technologies in a program that will have high visibility to key markets and decision-makers
  • Establish a verification program as a collaborative effort, involving multiple organizations and experts from a variety of jurisdiction and disciplines

There are four basic objectives for the evaluation of the technologies:

  1. Verify the "performance claimed by the vendor".
    How do these technologies perform over a range of flow rates?  
  2. Evaluate the technology as a Best Management practice for treating urban stormwater.  
  3. Evaluate the technology in a treatment train with other BMPs (where possible).  
  4. Evaluate the operation and maintenance costs, safety, and other operational issues.  

Space at this facility may be made available to other organizations or private corporations for stormwater research.  Contact Mark Maurer of the Highway Runoff Program at the Headquarters Design Office.