Maintaining Your Private Stormwater System

Properly maintaining a stormwater system is important whether you are part of a neighborhood or a business. Rain becomes runoff when it flows over yards, sidewalks, roads, driveways and parking lots. Along the way the water collects pollutants such as vehicle oil, fuel, brake dust, pet waste and other contaminants Eventually this water empties directly into our streams, rivers, lakes and Puget Sound. Stormwater systems are designed to collect and control runoff. They play a key role in preventing flooding, pollution and erosion. Stormwater systems include structures such as catch basins, ponds and ditches, which require periodic maintenance to ensure they function properly.

Property Owner Requirement

Pierce County requires property owners to inspect and maintain stormwater systems on their private property - including systems on commonly owned land. That means you and your neighbors are all owners of the stormwater system and all responsible.  Pierce County inspects private stormwater systems at businesses and in residential developments to ensure they are functioning properly, and pollutants are not entering the drainage system and surface waters in Pierce County. If the system is malfunctioning the owner(s) is the responsible party to make maintenance improvements.

To schedule a courtesy inspection to ensure your system is functioning properly, call (253) 798-2725.

Best Management Practices

Best management practices are steps you can take to prevent runoff from coming into contact with pollutants. Examples include covering a pile of exposed soil to prevent erosion, moving drums of waste to a covered area, and having a spill kit on hand to prevent spills from spreading.

Legal Authority

The Environmental Protection Agency (EPA) has authorized Washington State Department of Ecology (Ecology) to develop and administer the Municipal Stormwater Permit in the state. in addition, the State Water Pollution Control Act (Chapter 90.48 RCW) provides Ecology the authority to issue a separate state waste discharge permit. Ecology has chosen to combine that permit with the National Pollution Discharge Elimination System (NPDES) permit. Pierce County is regulated under Phase I of the NPDES. Pierce County has established the following ordinance, and others, to comply with federal and state regulations: Pierce CountyCode 11.05


Visit our Resource Library for more information about managing private stormwater systems.
Best management practicesChapters and other documents regarding best management practices in the Pierce County Stormwater Management and Site Development Manual 
Contact Us
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Kimberly Stanfield
Water Quality Supervisor
Phone: (253) 798-3096
7:30 a.m.–4:00 p.m.
Mailing Address:
2702 S 42nd St, Ste 201
Tacoma, WA 98409-7322