Restoring Beaver Creek

Beaver Creek is the primary spawning tributary for the large migratory rainbow and brown trout that move up from Holter Reservoir in the spring and fall. Many anglers from across the state come to the Missouri River specifically the Hauser tailwaters, to fish for these trophy size trout. The 2017 Hauser tailwater angler report (Montana FWP, Adam Strainer) observed 22,834 angler days. This Missouri River fishery (section 10A) that Beaver Creek supports is ranked 22nd in the state and 5th regionally and brings approximately $7.5 million dollars in revenue to the Helena area.

Location of Beaver Creek restoration project
map showing location of Beaver Creek  

Beaver Creek is listed as an impaired stream by the Montana Department of Environmental Quality for both sediment and riparian damage. The Forest Service and the Montana Department of Fish, Wildlife and Parks have also noted declines in spawning rainbow trout over the past 20 years due to angling pressure, predation, whirling disease, and continued habitat degradation.

The restoration project will be implemented in two phases and restore approximately 1.2 miles of lower Beaver Creek. Phase I was implemented the fall of 2020 in partnership with NorthWestern Energy, Montana Fish Wildlife and Parks, Pat Barnes Trout Unlimited Chapter and the Helena-Lewis and Clark National Forest. Phase II will hopefully be implemented the Fall of 2022 but, is contingent on funding and resource considerations.  

Project goals are to improve fish habitat, water quality, restore floodplain connectivity to support riparian vegetation and create additional wetland habitat. Treatments include reconstructing the channel to former floodplain elevations to create additional stream meanders (sinuosity) since the stream was artificially straightened to support agricultural practices.  Restoring the stream to historic elevations and expanding the floodplain will further support emergent and scrub-shrub wetlands. The University of Montana Bird Ecology lab will continue to monitor bird communities pre/post project implementation. Newly constructed pool and riffle stream habitat features will improve rearing and spawning habitat for trout with the goal of increasing natural recruitment.

The project is designed to raise the groundwater table and recharge the aquifer to support the riparian and wetland communities and maintain connectivity with the Missouri River even in drought years. This will take some time and currently, surface flow is lost at the lower end of the constructed channel. This, however, is not uncommon after large restoration projects given the area of disturbance, raising the elevation of the channel in parts, and timing of construction into late fall.  Subsurface flow conditions can persist in the short-term especially in watersheds such as Beaver Creek that have been literally disconnected from the floodplain for decades. Once the alluvial aquifer is recharged after a couple spring run-off events, surface flow is usually restored. In fact, monitoring on many other projects in the area have observed that base flows actually increase with increased aquifer storage resulting from reconnection of the stream channel and floodplain.

Beaver Creek completed channel
Completed channel and floodplain construction looking downstream toward station 26+50. The new channel was raised, and the old channel in part was converted to a connected ephemeral wetland area with placement of beaver dam analogs.

Total project construction cost for Phase I was $462,590 and this included the time of many volunteers including students from Capital High School, the Montana Discovery Foundation and Pat Barnes Trout Unlimited Chapter. Below are pictures that capture project implementation and volunteer efforts from last fall.

 Beaver Creek volunteers
Pat Barnes Trout Unlimited members and Capital High School student willow collecting

More information:

Phase 2 design plans and overview (74.8 MB)

News coverage:

Restoration underway for major trout spawning stream near Helena - Helena Independent Record; November 2020


Last updated: May 21, 2021