Stormwater

The Public Works Department has prepared a Stormwater Management Program (SWMP) as required by the National Pollutant Discharge Elimination System (NPDES) Phase II Municipal Permit (Permit) issued by the Washington State Department of Ecology (Ecology). This program was implemented to improve the quality of water discharged from the city's storm drainage system into the Green River via Newaukum Creek and into the White River via Boise Creek. The permit requires the city to submit Annual Reports on its stormwater activities and annual updates to its SWMP Plan for future stormwater activities. These documents can be found at the links provided at the bottom of the page.

Ecology Manual

To mitigate for impacts associated with stormwater runoff, the city requires that stormwater management practices be designed, constructed, operated and maintained in accordance with the Stormwater Management Manual for Western Washington (SWMMWW) prepared by Ecology. The current SWMMWW can be accessed from the Ecology website.

Illicit Discharge Reporting

If you are aware of a spill (illicit discharge) into a stormwater system, ditch or waterway please contact:

  • Public Works Department: Monday to Friday, 8 a.m. - 4:30 p.m.
    • (360) 825-3593 or (360) 825-5541
  • Enumclaw Police Department: After hours and holidays
    • (360) 825-3505

For Spills and other environmental issues outside the city limits contact the Department of Ecology Southwest Regional Office at Ecology Spills.

Low Impact Development (LID)

Low Impact Development is a stormwater management strategy that strives to mimic natural pre-disturbance hydrologic processes of infiltration, filtration, storage, evaporation and transpiration by emphasizing conservation, use of on-site natural features, site planning, and distributed stormwater management practices that are integrated into a project design. As required by the Permit, implementation of LID principles and LID best management practices (BMPs) on all new development and redevelopment projects are required within the city where feasible. In addition to the SWMMWW, information on LID can be found from the following resources:

Private Stormwater Facility Maintenance

The City of Enumclaw requires property owners to inspect and maintain their private stormwater facilities annually. Inspections and maintenance shall be performed in accordance with the Maintenance Standards for Drainage Facilities found in the SWMMWW (Appendix V-A: BMP Maintenance Tables) and as established by the manufacture. It is important that property owners maintain these systems to prevent flooding and pollutants from entering the storm drainage system and downstream surface waters of Enumclaw. More information on identifying and maintaining your stormwater facilities can be found at Stormwater Partners.

Stormwater Management Program Reports

The City annually updates its Stormwater Management Program Plan to incorporate new permit requirements and make improvements where necessary. The City's current Stormwater Management Program Plan and annual report of activities performed last year can be found at the below links.