Stormwater Projects

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.

PROJECT UPDATE:  Repair of the trail asphalt will run from Tuesday, April 25, through Saturday, April 29. A detour route will be posted.

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.

Trail Detour Map

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

“Graffiti Wall” Cleanup to Prevent Further River Pollution

The City’s Stormwater Utility is teaming up with the Clark Fork Coalition on Earth Day, Saturday, April 22, to remove the accumulated layers of paint on a wall known as the “graffiti wall,” which is located at the south end of the California Street Pedestrian Bridge. The wall is on private property, so the groups are working with the property owner to remove the many, many layers of paint that are flaking off in chunks as our weather undergoes freeze and thaw cycles. These paint chunks are being washed into the Clark Fork River with snowmelt and rain, polluting the river.  

The wall is not an approved canvas for public art. It is on private property, and the owner never sanctioned it as being available for public art.

For information on how to join the efforts to clean up the river before spring runoff, visit www.clarkfork.org.

South Hills Stormwater Improvement Project

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.

South Hills Project Slideshow Presentation (pdf)

Public Meeting Presentation Video

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 1 Area Map

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:

• Gharrett St. (55^th St. to Rufus Rd)
  • Re-grade a portion of the street to eliminate ponding.
  • Install ADA crossings and curb and gutter extensions.
• Bonnie Ct., Anthony Ln, Highwood Dr., and Valley View Dr. Intersections – Improve gutter on west side of intersection.
• Storm Drain Extension – Extend stormwater main about 590 linear feet from Cardinal Dr. to Arcadia Dr., and install new inlets at intersections.
• Water Quality Unit – Install a new hydrodynamic separator (HDS) into the new storm drain system to serve the Gharrett St. drainage. The HDS will improve water quality by removing large debris from the stormwater before it makes its way to the Bitterroot River.

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 2 Area Map

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
• construct a forebay to improve access to the pond for easier maintenance.

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.

Phase 3 Area Map

Project Contact:   Adam Marsh, Utility Engineer, email MarshA@ci.missoula.mt.us or call 406-552-6679

Clark Fork River Levee Maintenance Work—Completed

Intermittent North Riverfront Trail Section Closures

Location:  Along the North Riverfront Trail in two sections—between the California Street pedestrian bridge and Russell Street and also between the Madison Street Bridge and Orange Street Bridge.

UPDATE Monday, March 6—Levee work adjacent to the North Riverfront Trail between the California Street pedestrian bridge and Russell Street bridge has been completed, and the trail is open. All other work continues.

UPDATED Project Dates:  Work is now planned to begin Tuesday, February 28, with an anticipated completion date by March 14. These dates are subject to change due to adverse weather conditions and other factors.

Description:  The City's Stormwater Utility manages the Clark Fork River levees, which includes routine vegetation maintenance, which generally requires intermittent closures of the adjacent trail. 

Trail closure details:

• Portions of the North Riverfront Trail system will be closed from 9 a.m. to 4 p.m. weekdays. 
• Trail closures are timed to avoid peak commuter traffic times, but trail users should plan for a few extra minutes of travel time during the project.
• The portion of the trail between the California Street pedestrian bridge and Russell Street bridge will be detoured to nearby Cedar and California streets while crews complete the vegetation removal work. The pedestrian bridge and the trail east of the pedestrian bridge will both remain fully open to trail users. COMPLETED - This section of trail fully open.
• For the trail section between the Madison Street and Orange Street bridges, a prearranged detour route has not been defined due to winter road conditions and other factors. Cyclists and pedestrians are advised to use parks, streets, and sidewalks as needed to travel around the trail closures.
• Trail closure updates will be posted on this web page.

Trail Closure & Detour Maps

Background Information:  The U.S Army Corps of Engineers requires vegetation maintenance to preserve levee structures. This includes removal of trees with trunks larger than 4 inches and non-native trees and shrubs on the levees. To comply with Army Corps regulations that require removal of all trees within 15 feet of either side of the floodwall and levee structures, some trees in the adjacent park areas and along the floodwall must be removed. Missoula Parks and Recreation staff will plant replacement trees in areas that don’t encroach on the levee boundaries.

Stormwater Utility staff also collaborated with Missoula Parks and Recreation staff to identify the non-native vegetation that will be removed from the levees. They also consulted with Montana Fish, Wildlife, and Parks to obtain the necessary permit. The Clark Fork River will not be disturbed during this work.

Benefits:  Engineers from the Army Corps will be inspecting the levees in the near future, and the levees could lose their accreditation if not properly maintained. Having the levee system constructed and maintained so that it could be accredited by the Army Corps is critical for the homes and businesses protected by the levees to prevent flooding. In addition, non-accreditation of the levees would cause all businesses and residences protected by the levees to either obtain or increase their flood insurance coverage.

Project Contact:  Tracy Campbell, Stormwater Utility Superintendent, at CampbellTL@ci.missoula.mt.us or 406-830-5455