The purpose of the Fleshman Creek Urban Restoration Project is to restore and enhance a two-mile reach of Fleshman Creek, a tributary of the Yellowstone River near Livingston, Montana, and a wild trout resource currently suffering degraded habitat. Specific restoration outcomes include:
- 1) to restore Fleshman Creek Yellowstone cutthroat trout (YCT) habitat in an attempt to re-establish and strengthen population numbers;
- 2) to restore aquatic and riparian habitat;
- 3) to improve Fleshman Creek water quality and quantity;
- 4) to mitigate risks to property and life associated with flooding hazards; and,
- 5) to enhance Fleshman Creek as a community and educational resource and an improved public amenity.
In the fall of 2005, the U.S. Army Corps of Engineers performed a detailed hydrologic analysis of the Fleshman Creek watershed and determined that the 100-year discharge of 856 cfs is significantly higher than the capacity of many culverts through which the creek flows throughout the City of Livingston. When Park County and the City of Livingston began discussing the proposed Fleshman Creek culvert replacement project with the United States Federal Emergency Management Agency (FEMA) and Montana Disaster Emergency Services representatives, they were encouraged to take a holistic approach in restoring Fleshman Creek to a more natural and flood resistant state; to not only have the undersized culverts replaced, but to make other improvements to the watershed as well. It is expected that achievement of restoration outcomes, in addition to replacing the undersized culverts throughout the City of Livingston, will improve the channel's ability to convey floodwater and resist degradation during flood events, as well as improve fish, aquatic and riparian habitat.
This is truly a large-scale habitat restoration project uniting noteworthy partners from multiple federal, state and local agencies and groups, in both cash and in-kind support, including United States FEMA, Montana Department of Natural Resources, Montana Fish, Wildlife and Parks, Park County, the City of Livingston, Trout Unlimited, Livingston School Districts 4 & 1, Park County Conservation District and the Yellowstone River Conservation District Council.
This effort is a collaborative, multi-year approach that will combine extensive restoration, scientific research, community outreach and long-term conservation and monitoring methods to manage the improved stream channels and riparian areas. Fleshman Creek, in its current condition, is susceptible to flooding due to inadequate hydraulic structures and a narrow channel corridor. Replacement of the undersized hydraulic structures, and restoration of the channel corridor, will convey floodwaters to reduce the risk of flooding. Undersized and inefficient culverts will be replaced with hydraulic structures designed for high water events and water movement while reducing stream velocity. Fish movement will additionally be aided by the prevention of debris jams at pipe inlets. Newly contoured streambanks will be replanted with native woody and herbaceous vegetation aiding in bank stabilization, riparian protection, flood energy dissipation, pollutant filtration and improved water quality. Because Fleshman Creek does not suffer from significant geomorphic impairments, the potential for significant channel and fish, aquatic and riparian habitat restoration is easily achievable. Direct evidence of this potential can be observed in two successful restoration projects located both upstream and downstream of this project reach.
Excessive sedimentation and nutrient / pollutant loading has lead to anoxic conditions within the aquatic substrate, shallow water depths, noxious algae blooms, increased water temperature and low-dissolved oxygen conditions within the aquatic environment, all of which contribute to the degraded water quality and habitat conditions found in Fleshman Creek. Stormwater outfalls will be modified to prevent direct discharge to active stream flows and appropriately sized bio-swales, with the ability to provide 30 to 80 percent pollutant removal - including decreases in total suspended solids, total phosphorous, total nitrogen, floating trash, heavy metals, biological oxygen demand, bacteria, greases, oils and turbidity - would be used in series with hydrodynamic separators to maintain minimum velocities during scour events and provide increased treatment efficacy.