
NPDES Permit
The City of Newcastle holds a National Pollutant Discharge Elimination System (NPDES) Phase II Municipal Stormwater Permit required under the federal Clean Water Act and regulated in Washington State by the Department of Ecology. Each year, the City submits an Annual Report to the state summarizing efforts to meet permit requirements.
View Annual Reports in the Document Center.
Stormwater Management Planning
The Stormwater Management Plan (SWMP) is Newcastle’s long-term plan for managing stormwater and complying with the NPDES Phase II Permit. It outlines programs and practices to reduce pollution, prevent flooding, and protect local creeks, wetlands, and Lake Boren. The plan covers construction oversight, system maintenance, monitoring, and community outreach, ensuring a coordinated approach to keep stormwater systems functioning and waterways healthy.
The Stormwater Management Action Plan (SMAP) focuses on high-priority drainage areas, such as May Creek. It identifies actions to reduce flooding, control runoff, and improve water quality, helping the City use resources efficiently and guide projects that support the broader goals of the SWMP.
View Stormwater Management Plans in the Document Center.
Stormwater Management Programs
To carry out these plans, Newcastle implements a variety of stormwater management programs. These programs help plan, operate, and maintain the stormwater system while complying with the NPDES Phase II Permit. Together, these programs help stormwater flow safely, reduce flooding, and protect local creeks, wetlands, and Lake Boren.
Related Links
Report a Spill or Flooding Concern
For hazardous spills or urgent concerns:
206-296-3311
For non-hazardous spills:
425-649-4444 (business hours)
206-296-3311 (evenings/weekends)
For drainage or water quality concerns, Report an Issue.
