How is the City managing Stormwater?

The Natural Resources Program works cooperatively with other city departments to plan and manage the drainage system in Wilsonville. The Federal Clean Water Act, Safe Drinking Water Act, and Endangered Species Act direct the City to improve stormwater quality and protect watersheds, rivers, streams and drinking water resources.

Key Elements

Key elements of the city’s stormwater management program include:

• 2012 Stormwater Master Plan - The 2012 Stormwater Master Plan identifies areas of the city that currently experience erosion, flooding, and water quality problems, or that can be expected to experience such problems with future development.
• Public Works Standards (Section 3) - Public Works Standards (Section 3), outlines design and construction requirements for stormwater and surface water management. Provisions are intended to prevent or reduce adverse impacts to the drainage system and water resources. These requirements are intended to protect the beneficial uses, such as swimming, fishing etc., in the Willamette River.
• The Federal Clean Water Act requires municipalities to obtain a National Pollutant Discharge Elimination System (NPDES)  permit for stormwater discharges.   More information about our Municipal Separate Storm Sewer System (MS4) permit, including annual reports can be found here.
•  ​2022 Stormwater Management Program Document - The city’s Stormwater Management Plan (SWMP) is the means for complying with the NPDES permit and managing the city's stormwater system. All stormwater facilities on private property are maintained by the property owner or Home Owners Association.
• Total Maximum Daily Loads (TMDLs) - Total Maximum Daily Loads (TMDLs) - Total Maximum Daily Loads define the amount of pollutants that can be present in a water body without causing water quality criteria to be exceeded. Extensive water quality monitoring and modeling (for temperature, bacteria, and mercury) has been completed to establish Total Maximum Daily Loads for the Willamette River. The City’s first Willamette River TMDL Implementation Plan was approved by the Oregon Department of Environmental Quality (DEQ) in 2008. The City submitted its updated TMDL Implementation Plan to the DEQ in 2020.
• Erosion Control Program - Wilsonville recognizes the importance of protecting the environment and providing for the long-term stewardship of our natural resources. The Engineering Division has responsibility for managing the Erosion Control Permits.
• Wilsonville Code Chapter 8 - Environment - This section of the City code details City Stormwater regulations as they apply to system users, spills, sediment and erosion control, and other pertinent information.