Surface Water Management

Ash Avenue Park-and-Ride—Marysville, WA

Perteet developed the conceptual plan and site work for the 150-stall expansion of an existing park-and-ride. The project included the urban design plan for the neighboring area, plus the streetscape and shelter design. This project expanded the city sewer system by 1,337 feet and added a lift station to better serve properties along the city’s southwest edge. The job included a realignment of Ash Avenue, moving it a few feet to the east within the city's right of way to make room for more parking spaces, and provided an area for pedestrians to wait, a bus shelter, a bus pullout area, sidewalks, lighting and landscaping.

Budget impacts of conventional drainage methods nearly caused this project to be canceled. But by using low impact development drainage techniques involving a unique porous pavement and stormwater treatment system, we saved the city $400,000 in the cost of on-site facilities—plus the expense of one-mile of conveyance pipe. This system allows rain water to infiltrate through the pavers into an amended soil media where stormwater pollutants are captured and filtered through natural biotreatment processes using peat moss, prior to discharging into the groundwater. Creating an on-site stormwater treatment and innovative groundwater recharge method provides substantial construction cost savings, as compared with conventional stormwater treatment and disposal. State Department of Ecology officials prefer this design.

Extensive coordination with the City, Community Transit and the Washington State Department of Transportation (WSDOT) was key to the success of this project. The Ash Avenue Park and Ride improvements have been used by the Puget Sound Action Team as a model project and it won an ACEC award for “Exceeding Client Expectations.”

Riverfront Master Drainage Plan—Everett, WA

Perteet designed a master drainage plan for more than 120 acres of prime riverfront property along the Snohomish River. The plan included preparing storm collection system layouts, sizing water quality treatment and detention facilities, a storm pump station design, and outfall details to create a fish-friendly habitat along the stream bank. We also prepared construction cost estimates and a feasibility assessment and recommendations. The project scope included an assessment of possible environmental constraints, coordination with several city departments, public presentations, and preparing master drainage plan maps and reports.

Snoqualmie Ridge II - Low Impact Development—Snoqualmie, WA

Perteet prepared low-impact development (LID) drainage standards to be implemented by the City of Snoqualmie, in order to achieve a high level of stormwater quality management and environmental protection of the receiving waters.

Perteet staff gave presentations at public meetings on the benefits and uses of LID techniques for surface water management. The job also included conducting an environmental study on the benefits of LID, and preparing construction cost comparisons using LID techniques as compared with conventional drainage design.

Project Elements included a basin plan, hydrologic analysis, hydraulic design and a design study.