Stormwater Program


Program History

Starting in 2007, Benton County staff from Community Development, Environmental Health, and Public Works developed and successfully implemented a National Pollutant Discharge Elimination System (NPDES) program (see program brochure).

The program requirements are part of the Clean Water Act that local governments and private organizations must comply with for discharges of pollutants into the waters of the United States and regulating quality standards for surface waters. This means that there are many actions that the County is taking in the ‘urbanized areas' around the cities of Corvallis and Philomath known as the Federal Urbanized Area.

The overall goal of the Benton County Stormwater Program is to reduce the volume of runoff from current development (for example parking lots, subdivisions) and the developing landscape, while reducing the amount of pollutants carried by stormwater runoff to our rivers and streams. In order to meet this overall goal Benton County staff has developed and implemented Six Minimum Control Measures.

Benton County Stormwater Management Plan (SWMP)

The Benton County Stormwater Management Plan was developed by Benton County Community Development, Environmental Health, and Public Works in 2007 and adopted by the Benton County Board of Commissioners. Benton County updated its NPDES Phase II MS4 Permit on February 21, 2023 and the corresponding amendments to Benton county Code went into effect on March 23, 2023. Previous versions of the SWMP can be found in the Document Library under the "Historical Documents" section. 

Best Management Practices (BMP) Document

Benton County has established 'Best Management Practices (BMPs)' to help minimize environmental impacts of our daily work in County facilities, roadways, and construction sites. These Best Practices include proper erosion and sediment control and reducing our impact footprint on Benton County's natural resources.

Stormwater Program Related Code Documents and Applications

To view specific stormwater features, ​please visit our Benton County Storm App: BC Storm App Link. Guidance for regulations and enforcement under the Stormwater Program are included in the Benton County Code as well as the Benton County Land Development Code in the following chapters:

To view Erosion & Sediment Control Permit information and documents, please visit the Erosion & Sediment Control Permit page.

Benton County Code                                                                    Land Development Code
Chapter 21: Nuisance Abatement                                                Chapter 87: Goal 5 Resources
Chapter 23: Solid Waste Management                                        Chapter 91: Specific Use Standards
Chapter 31: Enforcement                                                              Chapter 99: General Development Standards
Chapter 36: Illicit (Non-Stormwater) Discharges