RUBY VALLEY, MONTANA

MILLER CATTLE CO.

In the 1950s, the river flowing through the property had been channelized, or straightened, to accommodate the agricultural operations on the ranch by making flooding more predictable and converting the floodplain into crop and grazing opportunities. The resulting steeper channel became incised and vertically disconnected from its former floodplain, which progressively lowered the water table and diminished riparian corridor habitat. The higher velocities stripped the gravel sizes necessary for spawning beds, diminishing the resident fish population, and the lack of sinuosity resulted in a near plane bed channel that lacked the habitat complexity of a healthy river.

The design phase identified a new alignment that would more closely resemble up and downstream intact reference reaches in sinuosity, slope, and prism. This new channel alignment would be built at a specific elevation that would allow flooding to access the floodplain, which is crucial for the propagation of woody riparian plants such as willow and cottonwood. The new shape and placement of the channel would dissipate excess, high-velocity water energy, which had led to stream bed and bank erosion and sedimentation for many decades.

The first fall after project completion saw the most brown trout spawning activity within the project reach the landowners had ever observed. The added sinuosity and the careful grading of the channel bed resulted in deep pools that have persisted in the years since, greatly enhancing the quality of the fishery. Analysis of pre and post-project sampling for both trout and riparian/wetland bird species identified a marked improvement in the numbers and diversity of both.