Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Hungry Horse Dam Fisheries Mitigation; Aquatic Modeling of the Selective Withdrawal System, Hungry Horse Dam, Montana, 1991-1993 Technical Report.

Technical Report ·
DOI:https://doi.org/10.2172/10174482· OSTI ID:10174482
Hungry Horse Dam presently releases frigid water from the bottom of the reservoir all year long. Cold water effects insect production and fish growth downstream. Rapid temperature changes of up to 8.3 C (14 F) have been measured in the Flathead River downstream of the South Fork confluence, controlled by dam discharges. Thermal effects from Hungry Horse Dam are detectable for over 64 Km downstream to Flathead Lake. The installation of a selective withdrawal structure on each of the dam`s discharge penstocks was determined to be the most cost-effective means to provide constant, permanent temperature control without impacting power production and flexibility in dam operation. The thermal model presented herein revealed that fish growth potential in the river would increase two to five times through selective withdrawal, temperature control. Temperature control is possible over the entire range of turbine discharge capacity, with very little effect on power production. Findings indicate that angling would improve through higher catch rates and larger fish. Temperature control will solve the most serious impact to river health. However, flow fluctuations will continue to effect insect production and usable fishery habitat in the Flathead River. A natural thermal regime combined with moderated flow fluctuation would further enhance riverine food production, trout growth and recreation potential.
Research Organization:
Montana Dept. of Fish, Wildlife and Parks, Kalispell, MT (United States); Montana State Univ., Bozeman, MT (United States). Dept. of Biology
Sponsoring Organization:
US Bonneville Power Administration.
OSTI ID:
10174482
Report Number(s):
DOE/BP-60559-1; ON: DE94016387
Country of Publication:
United States
Language:
English