what we do


Developing best management practices

Stormwater management practices and regulations have advanced rapidly in recent years. To reduce the impact of built areas, Parametrix uses low impact development (LID) principles and practices. Our solutions optimize the use of on-site natural features to improve water quality, protect habitat and wildlife, reduce life-cycle costs, and enhance communities. We apply the latest technologies to provide clients better ways to manage stormwater.

NPDES Stormwater Management Program
NPDES Stormwater Management Program 
​​Tacoma, Washington
Client: ​​​​​Lorig and Tacoma Housing Authority

Partner: David Evans & Associates

The Port of Tacoma constructs, operates, and maintains stormwater conveyance systems and outfall structures on Port-owned properties in the Tacoma Tideflats. The Port is one of two current Phase I secondary permittees in Washington State under the NPDES Municipal Stormwater Permit (MS4) program. The Permit outlines specific conditions pertaining to Port-owned conveyances, development and redevelopment requirements, and program management criteria. Parametrix is part of the team to support and assist with the analysis, planning, and programs that the Port develops and enacts to achieve long-term compliance with its permits and provide stormwater management services to Port facilities. The program will consider and seek to anticipate long-term permit and program needs and create a roadmap for future stormwater management activities, infrastructure, operations, maintenance, and permit compliance.



  • Manchester Stormwater Retrofit | Parametrix

    Manchester Stormwater Retrofit

  • NPDES Stormwater Management Program  | Parametrix

    NPDES Stormwater Management Program

  • Surface Water Comprehensive Plan Update | Parametrix

    Surface Water Comprehensive Plan Update

  • Newberg-Dundee Bypass | Parametrix

    Newberg-Dundee Bypass

  • Duwe’ig Stormwater Treatment Wetlands | Parametrix

    Duwe’ig Stormwater Treatment Wetlands

  • Parametrix Stormwater - SR 520 Bridge Replacement and HOV Program, Seattle to Redmond, Washington

    SR 520 Bridge Replacement and HOV Program


"Over the past year I have had the pleasure of working with the Parametrix team on the City's Storm and Surface Water Utility Comprehensive Plan Update. This has truly been a collaborative effort... working alongside city staff from a variety of departments and programs in addressing policy, regulatory and natural resources challenges."

Brian Ward, PE, Utilities Engineer, City of Bellevue, Washington