Why Manage Stormwater


The Washington State Department of Ecology has implemented the Western Washington Phase II Municipal Stormwater Permit to municipalities over 10,000 residents. The City of Centralia's population is 15,800. We are now a phase II permittee as required by the Department of Ecology. Phase II requires stormwater discharges to waters of the state (China Creek, Skookumchuck River, Chehalis River, Plumbers Lake, Borst Park Lake, Hayes Lake, and Agnew Mill Ponds) owned or operated by small municipalities and from small separate storm sewer systems (MS4s), located within urbanized areas to obtain a permit. The City of Centralia, as a regulated MS4, is required to comply with permit regulations.

The permit conditions include the preparation of a Stormwater Management Plan (SWMP). This plan was completed and adopted by the Centralia City Council in 2007. View the Stormwater Management Plan (PDF). The plan also requires the development of 5 control measures, that when properly implemented, will reduce pollutants to the maximum extent practicable (MEP). Additionally, annual reports must be prepared and submitted for approval to the Department of Ecology. The annual report is available by contacting the City of Centralia Utilities Office at 360-330-7512.

How Will We Manage Stormwater

The SWMP specifies 5 minimum measures that regulate municipal systems and must be in place to meet compliance. At a minimum, the City of Centralia is required to identify Best Management Practices (BMPs) for the following 5 control measures.

  • Public Education and Outreach
  • Public Involvement and Participation
  • Illicit Discharge Detention and Elimination
  • Controlling Runoff from New Development, Redevelopment and Construction Sites
  • Pollution Prevention and Operation and Maintenance for Municipal Operations

What Can You Do to Help

At Home:

  • Don't dump non-stormwater items (antifreeze, oil, paint) into storm drains
  • Wash your vehicles on a lawn or take to a car wash to reduce direct runoff into the stormwater system
  • Compost your yard waste
  • Pick up after your pet
  • Direct downspouts away from paved surfaces, use rain barrels, and/or add a rain garden