Stormwater System InformationSalmon

Stormwater runoff happens when rain or snow melt flows off impervious surfaces such as roofs, driveways, sidewalks, and streets which prevent the water from naturally soaking into the ground. 

Stormwater flowing across hard surfaces may pick up pollutants along the way such as oil, fertilizer, chemicals, dirt, litter, and other debris. When runoff becomes polluted, it can harm the environment by flowing into Monroe’s surface water collection system. These waters eventually flow into our streams, lakes, wetlands, and the Skykomish River.

The Department of Ecology’s Stormwater Management Manual for Western Washington has been adopted for reference by the Monroe City Council. The City is required by Federal Law to maintain an operating permit, which is generally referred to as the National Pollutant Discharge Elimination System permit. Collectively these documents provide the required foundation for the majority of the City’s stormwater management program activities.

The National Pollutant Discharge Elimination System permit requires the City to post select documents for public review and comment. Below, you will find links to the City’s annual stormwater system report, the stormwater management program plan, and the quality assurance project plan.

Stormwater Management Plan (SWMP) Public Comment 

The Stormwater Management Program is a set of actions and activities performed by the City to comply with Section S5 of the City’s Phase II Municipal Stormwater Permit. The SWMP is provided as a means to inform the public of planned activities for the upcoming calendar year and is updated annually.  The City of Monroe welcomes public comment on the Stormwater Management Plan (PDF) throughout the year. If you have comments regarding the 2020 report or suggestions for our 2021 plan, please email

National Pollutant Discharge Elimination System Document Links

Stormwater Management Program Plan (PDF)

Stormwater Annual-Report (PDF)

Quality Assurance Project Plan (PDF)

Stormwater Contact Information

Please report clogged storm drains and accidental spills to the City of Monroe.

If you have questions regarding the City of Monroe’s Stormwater Management Program, please visit Monroe Listens or call 360-794-7400 during normal business hours.

Report illegal dumping or spills that are potentially life threatening or hazardous to the environment by calling 9-1-1.