Habitat Evaluation Procedure (HEP) was developed by the U.S. Fish & Wildlife Service (USFWS) and designed for use in habitat inventory, impact assessment, and mitigation.
Habitat Suitability Index (HSI), used as part of the procedure, can include an extensive array of variables: water quality, instream cover,
average and maximum depth, substrate composition, percent fines, and proportion of specific habitat types.
TRPA Fish Biologists have extensive experience conducting salmonid spawning gravel evaluations,
and salmon and trout spawning surveys.
Other habitat evaluations TRPA Fish Biologists have conducted include fish barrier analysis for
natural high gradient impediments,
low flow passage issues,
and man-made barriers.
TRPA Fish Biologists also conduct large woody debris surveys (as seen above),
and stream margin organism stranding surveys during managed and unmanaged recreational boating flow down-ramping events and hydro-peaking operations.