Stormwater Projects

Pattee Creek Restoration Project - Phase II

Description: This project involves continued revegetation along the riparian areas of Pattee Creek along Pattee Creek Drive. We aim 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:

• improving the water quality of Pattee Creek by using vegetation to mitigate temperature and sedimentation increases;
• improving the riparian area of the creek by restoring vegetation to promote vegetative cover, sinuosity, and bank stabilization;
• supporting a healthy habitat for native aquatic species;
• education and outreach to landowners that reside along the creek in the right-of-way; and
• landowner participation and investment in the project.

Details: This project is the second phase of the long-term goal of restoring and revegetating all 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. 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. The project is also providing opportunities for education and outreach concerning healthy riparian areas. We have partnered with some citizens of the Pattee Creek watershed to form “Friends of Pattee Creek,” a community action group to steward the creek and its needs.

Coordination: This project has been planned and supported through a partnership between the City of Missoula Stormwater Utility and Missoula Conservation District. MCD has a similar revegetation project in the upper watershed. For more information, please reach out to JuliaDrennan@macdnet.org.

Project Funding: The first phase of the project was funded by Big Sky Watershed Corps (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. This year’s funding is provided by a supplementary grant of $5,000 from MDEQ. These funds will primarily be used for planting materials.

Project Dates: A volunteer day for project implementation will be held September 15, 2023, starting at 10 a.m. Volunteers are welcome to participate in accordance with their availability and capacity. We will be providing all materials, in addition to a free lunch from Tagliare Delicatessen.

Project Contact: Lyndsey Holloway, Project Manager, at HollowayL@ci.missoula.mt.us or call 406-493-8031

South Hills Stormwater Improvement Projects

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 Morningside 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 June 26 with completion expected by August 28. All project dates are subject to change due to adverse weather conditions and other factors. This page will be updated as necessary during the project.

Grandview Way Project Area Map

Project Contact:  Adam Marsh, Utility Engineer, at MarshA@ci.missoula.mt.us or 406-552-8835

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 helps 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:  Work begins July 10, 2023, with completion expected by September 28. These dates are subject to change to due inclement weather or other factors. This page will be updated as needed.

Gharrett Street Project Area Map

Detour Maps — Work will start at Briggs St. and move south to 55th St.

ADDITIONAL INFORMATION

Traffic Control and Safety:  Maintaining a safe work environment, both for our crews and the general public, is extremely important to the City. Road closure signs will be used to divert thru-traffic while crews are actively working on certain blocks. Local traffic for residents needing access to their driveways will still be allowed though you may have to work with the contractor to accommodate your individual access needs.   

On-Street Parking:  When the City’s contractor is ready to mobilize their equipment to work on a particular block, they will post signs for all cars currently parked on that block to move within 24 hours. If those cars are not moved within that period, the contractor will arrange to have them towed to a side street adjacent to the project.

Project Contact:  Adam Marsh, Utility Engineer, at MarshA@ci.missoula.mt.us or 406-552-8835

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:  Starts July 17, 2023, with completion expected in October. Plants will go in afterward as long as the weather and temperatures permit.

Cattail Corner Area Map

Project Contact:   Adam Marsh, Utility Engineer, email MarshA@ci.missoula.mt.us or call 406-552-8835

Previous public outreach on these projects:

South Hills Project Slideshow Presentation (pdf) (from April 7, 2022, public meeting)

Public Meeting Presentation Video

Cattail Corner Stormwater Improvements

Description:  This phase of the South Hills Stormwater Project 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. 

Primary goals for Cattail Corner include:

• increase stormwater infiltration capacity by installing dry wells around the 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 and less disruptive future maintenance.

This phase also includes the design and construction of two water quality unit retrofits on the existing storm main to remove debris from stormwater before it enters the rest of the stormwater system.

Public Benefits:  Makes Cattail Pond and wetlands into a well-functioning stormwater treatment facility that uses "green infrastructure" to treat urban stormwater. The result will be a healthier wetlands and pond area.

For information about green infrastructure, visit www.ci.missoula.mt.us/2678/Green-Infrastructure. 

Additional Information:  City staff, as well as the project's engineering consultant and contractor, worked with a wildlife biologist/ornithologist to determine the best time of year to begin the project so as to have the least amount of impact to the area as possible. 

Project Dates:  Starts July 17, 2023, with completion expected in October. Vegetation planting will begin right afterward as long as weather and temperatures allow. Otherwise, planting will take place in the spring of 2024. This post will be updated when additional information is available.

Cattail Corner Area Map

Cattail Corner Revegetation Plan

Project Contact:   Adam Marsh, Utility Engineer, email MarshA@ci.missoula.mt.us or call 406-552-8835

Previous public outreach on these projects:

South Hills Project Slideshow Presentation (pdf) (from April 7, 2022, public meeting)

Public Meeting Presentation Video

Gharrett Street Stormwater 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 helps 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:  Work begins July 10, 2023, with completion expected by September 28. These dates are subject to change to due inclement weather or other factors. This page will be updated as needed.

Gharrett Street Project Area Map

Detour Maps — Work will start at Briggs St. and move south to 55th St.

ADDITIONAL INFORMATION

Traffic Control and Safety:  Maintaining a safe work environment, both for our crews and the general public, is extremely important to the City. Road closure signs will be used to divert thru-traffic while crews are actively working on certain blocks. Local traffic for residents needing access to their driveways will still be allowed though you may have to work with the contractor to accommodate your individual access needs.   

On-Street Parking:  When the City’s contractor is ready to mobilize their equipment to work on a particular block, they will post signs for all cars currently parked on that block to move within 24 hours. If those cars are not moved within that period, the contractor will arrange to have them towed to a side street adjacent to the project.

Project Contact:  Adam Marsh, Utility Engineer, at MarshA@ci.missoula.mt.us or 406-552-8835

Previous public outreach on this project:

South Hills Project Slideshow Presentation (pdf) (from April 7, 2022, public meeting)

Public Meeting Presentation Video

Grandview Way Stormwater Improvements

Description:  This first phase of the project will extend stormwater mains up Rita Court and Morningside 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 June 26 with completion expected by August 28. All project dates are subject to change due to adverse weather conditions and other factors. This page will be updated as necessary during the project.

Grandview Way Project Area Map

Project Contact:  Adam Marsh, Utility Engineer, at MarshA@ci.missoula.mt.us or 406-552-8835

Previous public outreach on this project:

South Hills Project Slideshow Presentation (pdf) (from April 7, 2022, public meeting)

Public Meeting Presentation Video

Bitterroot Outfall Project

Location:  On the Bitterroot River just south of the Highway 93 bridge.

Description:  The project will include improvements to the outfall area to address Bitterroot River water quality impairment from stormwater flow from Pattee Creek. Sediment from the swale area is deposited in the river.

• Best Management Practices (BMPs) to address heavy loads of sediment that reach this outfall. The source of sediment is primarily due to road sanding operations in the South Hills during the winter. BMPs could include a hydrodynamic separator installed upstream of the outfall or a sediment forebay that enables sediment removal in a designated location. To facilitate maintenance of this type of BMP, a bypass channel or pipe would be installed.
• Clearing sediment from the energy dissipaters so that they are fully exposed.
• Removal of trees and vegetation that is encroaching on the facilities before damage occurs. 
• Re-grading or otherwise modifying the swale so that flow meanders through and accumulated sediment can settle out.
• Additional vegetation to provide enhanced nutrient uptake and sediment deposition.
• Upgrading the undersized culvert crossing located downstream of the flap gate to accommodate the 1% annual chance flood event.

Benefits:  Improved water quality in the Bitterroot River by improving infrastructure so that sediment is better filtered and settled out of the stormwater before it reaches the river. Planting and installing better green infrastructure helps remove nutrients from the stormwater as well.

Project Dates:  Construction is anticipated in 2025. This page will be updated as further information becomes available.

Public Meeting:  A public meeting was held on July 12, 2023. Link to Bitterroot Outfall meeting recording

Area Map—coming soon

Project Contact:  Adam Marsh, Utility Engineer, at MarshA@ci.missoula.mt.us or 406-552-8835

Clark Fork River Levee Repairs - Russell St. to California St. Pedestrian Bridge—Completed

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.

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