Beaver Creek is a third-order tributary
to Keep Cool Creek in the Upper Blackfoot Watershed. The source of Beaver Creek is a
natural lake called Reservoir Lake. From this source it flows south nine miles to its
confluence with Keep Cool Creek with base flows of approx. 6 - 10 cfs. The forested
headwaters are part of the Helena National Forest. As the stream enters the wide
lower valley, the ownership changes to state and private property. On the private
property the stream enters a large scrub-shrub beaver system encompassing several hundred
acres in size. Historically, Beaver Creek supported healthy populations of bull trout and
westslope cutthroat trout.
The native fishery is
impacted by four irrigation ditches located towards the mouth of Beaver Creek. These
diversions not only block upstream migrations but also entrain downstream migrating
fish. Riparian management in the lower reaches of Beaver Creek have also impacted the
stream because of improper grazing practices and riparian logging. In order to prioritize
restoration resources, we developed a fisheries-based restoration priority scorecard,
based on biological, social and financial considerations, for 83 impaired tributaries of
the Blackfoot River. Beaver Creek is ranked 7 of 83 streams surveyed.
Restoration and protection of the
Beaver Creek system began in 1997 with reconstruction of the two upper most irrigation
diversions. The upper most diversion was completely replaced with a rock weir
structure that allows for upstream fish passage as well as bedload movement. The
lower diversion was fitted with a fish ladder for passage.
In 1999, a conservation easement was
secured on 90% of the private property in the watershed (2,800 acres). The
conservation easement protects the ranch in perpetuity from sub-division, draining or
degrading wetlands, sod-busting of native prairie, and commercial timber harvest.
|Aerial view of the Beaver Creek Watershed. In the foreground is the private
property protected by the conservation easement.