Testing the instream flow method in trout streams

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:219929

Studley, T K ^[1]; Railsback, S F; Asce, M ^[2]

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1. Pacific Gas and Electric Company, Sam Ramon, CA (United States)
2. Railsback & Associates, Arcata, CA (United States); and others

Pacific Gas and Electric Company`s (PG&E) Department of Research and Development and co-sponsors are fieldtesting the Instream Flow Incremental Methodology (IFIM) at a number of trout stream study sites. Fish populations, flows, and other variables were measured for an eight-year baseline period. Three levels of increasingly sophisticated predictions of population response to increased flows were made. The flow increases have been implemented and additional data are being collected to test the predictions. The baseline data and prediction analyses indicate that (1) using different habitat suitability criteria produces substantially different predictions of how populations respond to flow changes, (2) overlaps in habitat used by trout species can lead to misleading predictions of a population`s response to flow changes, and (3) factors other than habitat during summer low flows can limit trout populations (these include spawning habitat, high flows, stream channel characteristics, and stream temperature). Comprehensive field studies are expensive, but are more likely to result in instream flows that provide a cost-effective tradeoff between power and fisheries values.

• OSTI ID: 219929
• Report Number(s): CONF-9507190--
• Country of Publication: United States
• Language: English

Related Subjects

13 HYDRO ENERGY
CALIFORNIA
DAMS
ENVIRONMENTAL EFFECTS
FLOW RATE
FORECASTING
HABITAT
HYDROELECTRIC POWER PLANTS
POPULATIONS
STREAMS
TESTING
TROUT