Stormwater projects can include dry well installation, maintenance, and cleaning; levee maintenance; and various other project that address how stormwater makes its way through Missoula. This page provides information on projects scheduled for 2022.
Clark Fork River Levee Repairs - Russell St. to California St. Pedestrian Bridge
Description: The U.S. Army Corps of Engineers will be leading Repairs to Clark Fork River Levee between Russell St. and the California St. pedestrian bridge on the north bank of the river.
Benefits: The levee helps protect the businesses and residences behind it from flooding during high-water events. Repairing the riverbank and replacing the large rock, known as riprap, with larger rock will reduce the likelihood of major bank erosion during future high-water events. Having the levee constructed and maintained so that it could be accredited by the Army Corps is critical for the homes and businesses protected by the levee to prevent flooding. In addition, non-accreditation of the levee would cause all businesses and residences protected by it to either obtain or increase their flood insurance coverage.
In addition to placement of larger riprap, native grasses will be planted on this section of the levee as additional help in preventing erosion with the added benefit that the grass lessens the amount of heat directed toward the water. The riprap reflects the sun's heat onto the river, warming the river's water temperature, which has a negative effect on fish species.
Details: The U.S. Army Corps of Engineers will be conducting the work, which is necessary to repair damage to the levee caused by erosion during previous high-water events. Strong river currents displaced much of the riprap along the riverbank.
Trail Detour: Because the area where the levee repairs will take place is adjacent to the Riverfront Trail, a section of the trail will be detoured to nearby Cedar and California streets. Any delays caused by the detour should be minimal as the California St. pedestrian bridge and Riverfront Trail east of the pedestrian bridge will be fully open to all trail users.
Project Funding: The U.S. Army Corps of Engineers is funding the repairs.
Project Dates: The repairs are expected to begin Tuesday, November 8, but the finish date has not yet been determined. This page will be updated as soon as the estimated completion date is available.
Project Contact: Tracy Campbell, Stormwater Utility Superintendent, 406-830-5455 or CampbellTL@ci.missoula.mt.us
A public meeting was held Thursday, April 7 at 6 p.m. to discuss project goals, scope, schedule, and funding for all three project phases fully described below.
Questions? Contact Adam Marsh at MarshA@ci.missoula.mt.us or 406-552-6679.
The City of Missoula won a $2 million American Rescue Plan Act (ARPA) grant to improve stormwater infrastructure in the South Hills. This grant, along with a 10% local match, will fund design and construction of stormwater improvements in the South Hills. This stormwater infrastructure improvement project will take place in three phases:
Phase 1—Grandview Way Improvements
Description: This first phase of the project will extend stormwater mains up Rita Court and Morning Side Court.
Public Benefits: This work will alleviate issues with spring water flowing from private property into the City right of way. Following 2015 and 2020 earthquakes in the South Hills, new springs emerged on private property near Grandview Springs. These springs flow year-round, depositing more water on private property than the homeowners can handle. The water then ends up flowing onto adjacent sidewalks and streets, causing public safety issues when the water freezes. In addition, the excess water on the streets and sidewalks–including freezing and thawing cycles–damages the infrastructure, requiring frequent repairs and shortening its lifespan.
Project Dates: Phase 1 is expected to begin this summer. More details will be posted here once available.
Phase 2—Gharrett Street Improvements
Description: This phase of the project will address a variety of stormwater issues along the Gharrett Street corridor, including the following:
Public Benefits: Improved removal of stormwater from City streets. This help prevent ice from forming on streets and adjacent sidewalks, which can be a safety hazard for pedestrians, motorized vehicles, and bicyclists. It also prevents accelerated damage to street and sidewalk infrastructure.
Project Dates: To be determined. This post will be updated when information is available.
Phase 3—Cattail Corner Improvements
Description: This project phase will improve how Cattail Corner functions as a stormwater treatment wetland. Additional work will be done to offset increased flows to the storm drain system due to the Gharrett Street project (Phase 2). Primary goals for Cattail Corner include:
- increase stormwater infiltration capacity by installing dry wells around pond,
- restore stormwater retention capacity by removing accumulated sediment,
- improve natural biological treatment of urban stormwater (additional water volume in the pond allows the stormwater to remain in the pond longer, providing more time for plants to remove and process nutrients in the stormwater),
- increase wetland biological diversity and habitat values by planting additional native plant species and removing invasive species, and
This phase also includes the design and construction of two water quality unit retrofits on existing storm main to remove debris from stormwater before it enters the rest of the stormwater system.
Public Benefits: Makes Cattail Pond into a well-functioning stormwater treatment facility that uses "green infrastructure" to treat urban stormwater. For information about green infrastructure, visit www.ci.missoula.mt.us/2678/Green-Infrastructure.
Project Dates: To be determined. This post will be updated when information is available.
Project Contact: Adam Marsh, Utility Engineer, email MarshA@ci.missoula.mt.us or call 406-552-6679
Pattee Creek Restoration Project—Completed
Pattee Creek Restoration & Planting Event: Friday, October 7, 2022, from 9 a.m. to 3 p.m. Volunteers welcome for any portion of this time. Email Mackenzie Tenan at firstname.lastname@example.org to receive an event survey and more details.
Description: This project involves revegetation along the riparian areas of Pattee Creek on Pattee Creek Drive. This is implemented to mitigate water quality issues such as alteration in stream-side or littoral vegetative covers, flow regime modification, temperature, and sedimentation brought upon the creek due to the impacts from residential development.
Benefits: The major benefits of this project include:
Details: This project will be the foundation of the long-term goal of restoring and revegetating throughout the entirety of Pattee Creek. According to the Bitterroot Watershed Restoration Plan, the creek “is a stream of concern in the Bitterroot watershed” since it is a tributary to the impaired Bitterroot River. It will reduce impacts of alterations in streamside and littoral vegetative covers, sedimentation, and temperature where the waterbody is channelized adjacent to residential development.
Because the creek is within the City right-of-way and flows through residential development, it is particularly susceptible to water quality issues. The project is also providing opportunities for education and outreach concerning healthy riparian areas. Public meetings, educational pamphlets, and Healthy Riparian Guidebooks will support this education and outreach goal. Participating landowners will maintain these boulevards by not mowing up to the creek within the established buffer or significantly altering the newly planted native vegetation. Ecological stewardship within the community will be a focus to provide protection from current nonpoint source pollution, as well as creating resiliency to protect from future nonpoint source pollution. Further emphasis on community and education outreach will be demonstrated by involving community volunteers in the revegetation event to plant and install browse protection.
Coordination: This project has been planned and supported through a partnership between the City of Missoula Stormwater Utility and Missoula Conservation District by hosting a Big Sky Watershed Corp (BSWC) Member, Mackenzie Tenan. As the project manager, she will have the support of both entities to complete the project deliverables:
Project Funding: With fundraising help from the BSWC Nonpoint Source Project Support Grant provided by the Montana Watershed Coordination Council (MWCC) and Montana Department of Environmental Quality (MDEQ), the project was awarded approximately $5,300. In addition, supplementary grant money from MDEQ awarded the project another $4,975. These funds will primarily be used for planting materials.
Project Dates: There will be a public meeting about the project hosted by the City of Missoula Stormwater Utility and Missoula Conservation District on Wednesday, June 15 at the Outdoor Classroom at Bancroft Ponds. The planting event will be scheduled for early October with an official date to be released.
Project Contact: Mackenzie Tenan, Project Manager, at email@example.com or call 406-552-6379
Caras Park – Stormwater Outlet Phase II Project—Completed
January 2022 Update—The infiltration gallery has been installed. The headwall and flap gate will be installed once weather permits in the spring. Final grading will also be completed once weather conditions will allow.
Description: The project involves installing a stormwater infiltration gallery under Caras Park and a small concrete headwall at the outfall pipe into the Clark Fork River just downstream from Brennan’s Wave. The headwall allows for a flap gate to be installed, preventing backflow into the infiltration system when the river is at higher levels.
Benefits: The major benefits of this project include:
- improving the water quality of the Clark Fork River by treating the stormwater with the highest concentration of contaminants from the downtown area before it enters the river,
- providing health benefits for river recreationists by improving water quality,
- improving water quality by diverting warmer stormwater into the infiltration gallery, and
- complying with state water quality requirements.
Details: In 2017, a hydrodynamic separator (HDS) was installed under the park to pre-treat stormwater runoff collected from Missoula’s 60-acre downtown area by removing larger debris from the stormwater. The current project improves upon that treatment by diverting the first one-half inch of stormwater into an infiltration gallery to further prevent stormwater runoff from carrying contaminants into the river. This initial stormwater runoff during a weather event has the most concentration of contaminants gathered from streets, sidewalks, gutters, and other areas where water enters storm drains instead of filtering into the ground. These contaminants include oil, grease, and bacteria.
In addition, stormwater is usually warmed as it moves across asphalt and concrete pavements as it makes its way into storm drains. Warm water further degrades the river’s water quality because it has a negative effect on fisheries and can enhance growing conditions for algae blooms, which are also bad for fish.
After the new infiltration gallery is installed, the first one-half inch stormwater will be diverted into the infiltration gallery where it will be filtered through highly permeable soils and eventually enter the aquifer instead of emptying directly into the river. This is the same way most other stormwater in Missoula is handled once it enters a storm drain. For larger storms, after the first one-half inch has been infiltrated, the remaining storm water will still discharge to the Clark Fork River.
Coordination: This project was planned and is being coordinated with the City of Missoula’s Parks and Recreation Department. In conjunction with this stormwater project, Parks & Recreation will be implementing Phase 1 of the Caras Park Improvements outlined in the North Riverside Parks & Trails Plan, which was adopted by City Council in November 2020.
- To install the infiltration gallery, the berm in the park between the trail and the pavilion structure will be removed.
- Following structure installation, the area will be leveled to be more even with the brick plaza area around the pavilion, which aligns with Parks & Recreation’s plans. Removing the berm allows for an improved view of the river as well as room for trail widening and making the area usable for more activities.
- This stormwater project is being timed so that the park area will be disturbed only once instead of once for stormwater work and once for the first phase of the Caras Park project.
- By combining the efforts of the two departments, the City will realize a savings of about $100,000 in construction costs.
- Park “down time” will be minimized because we are completing the work at the same time as the Montana Department of Transportation constructs the Bear Tracks Bridge on Higgins Ave.
Project Funding: With fundraising help from the Missoula Downtown Foundation, the Parks & Recreation Department is able to begin the first phase of its North Riverside Parks & Trail Plan at the same time as we begin this stormwater project. We were able to bid both projects together, resulting in a savings of about $100,000 to the City of Missoula.
Project Dates: Work is expected to begin Oct. 4 with completion expected in Spring 2022. These dates are subject to change due to weather and other unforeseen circumstances.
Project Contact: Andy Schultz, City Engineer for Utilities, at SchultzA@ci.missoula.mt.us or call 406-552-6758
Maintenance Follow-Up Work on Levee III and Levee V—Completed
Description: This project involves further removal of tree stumps that were initially treated last spring after the invasive or large tree was removed from the levee. Stumps that have sprouted will be cut off and treated again. For more information on last year’s project and reasons for removal, please visit the 2021 Completed Stormwater Projects web page.
Project Dates: Scheduled to begin Tuesday, April 5, 2022, with completion expected around April 15. These dates are subject to change due to weather and other unforeseen circumstances.
Project Maps (pdf)
Trail Closure Information:
Because the trail will not be fully closed, no detour is needed. Cyclists and pedestrians are advised to use parks, streets, and sidewalks as needed to travel around the trail closure areas. Closures will be timed to avoid peak commuter traffic times. Please plan for a few extra minutes of travel time during the project.
Project Contact: Tracy Campbell, Superintendent for the Stormwater Utility, at CampbellTL@ci.missoula.mt.us or call 406-552-6364.