Stormwater Utility

StormwaterThe City of Redmond, through its NPDES Municipal Permit, is responsible for ensuring proper maintenance and operation of all public and private stormwater systems within the City. These include 363 miles of pipes, 23,500 catch basins and manholes, 940 vaults, 304 bioswales, 68 miles of streams, and 328 ponds throughout the City.

The Stormwater Utility: 

  • Ensures that public and private stormwater systems are planned, developed and maintained to prevent flooding, protect water quality and preserve natural stormwater systems
  • Monitors water quality and provides leadership and focus for community efforts working toward improved stormwater management
  • Identifies needs for capital improvement of the stormwater systems including streams and habitat, prioritizes, selects, and constructs those improvements
  • Ensures that City construction and maintenance projects are planned and implemented to cause as little short term and long term harm as possible to the environment

Managed by the Public Works Department, Environmental and Utility Services division, the Stormwater Utility funds support engineers, scientists, technicians, inspectors, project managers, and administrative specialists in several divisions within the City's Public Works Department. 

The City is addressing Stormwater Management in 3 phases:



  • Building & maintaining regional facilities
  • Low Impact Development (LID)
  • Stormwater Technical Notebook
  • Standard specifications & details


  • Building and maintaining stormwater ponds
  • Private drainage inspections
  • Spill Response (IDDE)
  • Maintenance and operations of public systems

Stormwater Technical Notebook Update (2022)

In early 2022, the City will undertake a review and update of the 2019 Stormwater Technical Notebook (STN).  The purpose of this update is to bring the STN in full compliance with the technical requirements found in Appendix 1 of the City’s 2019 NPDES permit, to improve readability, and to correct inconsistencies.  A draft version of the 2022 STN will be available for review and comment in late April.  

Contact Cindy Wellborn, STN Update Project Manager, to be notified about this project.