City of Arlington Constructed Wetland Design
(Arlington, WA) Landau Associates designed a 10-acre constructed stormwater treatment wetland for the City of Arlington that will serve as a sustainable, ecological connection between an existing Washington State Department of Transportation (WSDOT) wetland mitigation area and the Stillaguamish River corridor. Reclaimed water is pumped to the wetland where it is cleaned and cooled using natural processes, which improves water quality and fish habitat. The wetlands also provide flood storage, wildlife habitat, and open space. Our services included review of channel migration zone documents, evaluation of river and flood fringe areas that could impact the functioning of the wetland and outfall piping, and summarizing of findings in a Drainage Report prepared for Snohomish County. We prepared construction documents, a critical areas report, a Stormwater Pollution Prevention Plan, and permitting documents (shoreline, construction stormwater, general, grading, and WSDOT right-of-way). Engineering services included a geotechnical investigation for a trenchless pipe crossing under State Route 9 and a sampling and analysis plan for water quality investigation that outlined methods and procedures for sample collection, as well as an analysis of pollutant loading rates and treatment capacity.
The Puget Sound Partnership recognized the City of Arlington as a "Puget Sound Champion" for the stormwater treatment wetland's "exceptional work protecting and restoring habitat, cleaning up polluted water, and engaging the community in implementing the Action Agenda—the Partnership's regional plan to clean up Puget Sound."
Landau Associates and the City received a Joint Planning Award for the project from the Washington Chapter of the American Planning Association (APA) and the Planning Association of Washington (PAW).