Blanchard Creek is a
small tributary to the lower Clearwater River. Blanchard Creek was historically
dewatered in its lower one mile from irrigation withdrawal. Fish population surveys
in 1990 indicated this dewatering, associated poor fish passage at headgates for two
irrigation canals, and the Highway 200 stream crossing negatively impacted the fishery in
the lower reaches of the tributary. Other problems identified in the drainage were road
erosion and livestock impacts to the riparian area. 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. Blanchard Creek ranked 13 of 83 streams surveyed.
Interest in maintaining the health of
this stream by the ranch owners through maintenance of a minimum flow has resulted in a
water lease arrangement. The arrangement involves stopping diversion of stream flows once
Blanchard Creek reaches 3 cfs, which generally accommodates the early season of irrigation
for crop production. The release of flows after 3 cfs has resulted in some crop losses
late in the season that are being reimbursed at an agreed upon value.
"fish-friendly" diversion structures were constructed and fitted with fish
ladders at both diversion points. The culvert under Highway 200 was also modified to
facilitate fish passage. Improved riparian grazing management was initiated by Plum Creek
Timber Company and the Department of Natural Resource Conservation.