City Projects

Stormwater Division Duties

As appropriate we coordinate with other agencies and citizens to:

  • Educate the public on stormwater pollution prevention;
  • Screen, sample, and test stormwater for illicit discharges and pollution levels;
  • Report test results and other required activities to the Montana Department of Environmental Quality;
  • Coordinate response to stormwater flooding situations; 
  • Construct, upgrade, and maintain stormwater facilities (to view Missoula's Stormwater infrastructure and facilities, go to the stormwater web map and select the "Storm" Layer); and
  • To see a detailed view of all stormwater division duties review the Stormwater Facility and Operations Plan.

Image showing part of the Missoula Storm Water Map, including hundreds of drywells in a square mile area, with a link to the full page map. Opens in new window

Working Together

For the past 10 years, the City has collaborated with the Missoula Valley Water Quality District to enforce water quality laws, monitor groundwater cleanup sites, oversee household hazardous waste collection, and more. The community’s unique Missoula Water Quality Ordinance provides strong protection of Missoula's waterway through the regulation of discharges, such as dry cleaner solvents, as well as the use of street deicers. Enforcement and co-permit responsibilities are a partnership as defined by the 2003 Interlocal Agreement. This partnership continues following the creation of the Stormwater Division because both entities have similar goals but different tasks.

The Stormwater Utility Division also works with educational partners such as Montana Natural History Center and the Watershed Education Network. We are working together to cultivate and develop our future generations as stewards of Missoula's greatest treasures, our water.

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Major Water Quality Accomplishments

  • Extension of the sewer system in older areas of the community previously served by outdated cesspools and seepage pits;
  • Adoption of the first municipal phosphate ban in the Clark Fork River watershed, leading the way for other communities;
  • Stormwater and flood control improvements for the Pattee Canyon, South Hills, 39th Street, and Miller Creek areas;
  • Installation of treatment devices for stormwater discharges in downtown Missoula at Orange Street and Silver Park and planning for improved treatment at Caras Park and Buckhouse Bridge; and
  • Installation of the hybrid poplar project, 90,000 trees planted near the treatment plant and watered with effluent that would have gone to the Clark Fork River, eliminating significant amounts of nitrogen and phosphorous.

Meeting State and Federal Regulations

The Stormwater Discharge General Permit MS4 is managed by Montana DEQ to help ensure water quality, with each major municipality participating. Missoula's MS4 five year permit, effective January 1, 2017 - December 31, 2021 requires the City to have a full-time stormwater coordinator, increase hands-on education about stormwater pollution and prevention, as well as increase public participation.

The 2019 Annual Report reviews the City of Missoula’s StormWater Division’s activities for the 2019 MS4 permit year. For a broader look at planned activities see Missoula’s Stormwater Management Program (SWMP). This details local pollutants of concern, their reduction, and mitigation in the City of Missoula. Activities described are in accordance with requirements stated in the MT state General MS4 permit. Provide your comments in this online form or by contacting the Stormwater Division.

Beyond this MS4 General Permit the City of Missoula is meeting regulations to comply with the U.S. Clean Water Act and the Montana Pollutant Discharge Elimination System (MPDES).

The Missoula Valley Water Quality District (MVWQD), a division within the Missoula City-County Health Department, responds to illicit discharges.

If you would like to report an illicit discharge or have a stormwater construction site concern you may use the online reporting form or call 406-258-4890 during regular business hours or for an after-hours matter, please call 911.