A final environmental impact statement for relicensing the 1,166.5-MW Hells Canyon hydroelectric complex includes a Federal Energy Regulatory Commission staff proposal to increase downstream flows for juvenile fall chinook salmon migration.
FERC staff prepared the final EIS with an alternative also calling for: additional ramping restrictions during the fall chinook salmon rearing period; stricter reservoir refill targets after the flood control season; an 8,500-cubic-foot-per-second minimum flow downstream of Hells Canyon dam in some high water years; and warm water fish spawning protection levels in Brownlee Reservoir.
The EIS evaluates Idaho Power’s relicense application for Hells Canyon (No. 1971), a three-powerhouse complex on the Snake River in Idaho and Oregon. (HNN 8/16/06) It documents the views of government agencies, Indian tribes, the public, the license applicant, and FERC staff. FERC will consider the EIS when deciding on relicensing. Idaho Power has operated the project under temporary annual license since the original license expired July 31, 2005.
The staff alternative incorporates most of Idaho Power’s proposed environmental measures, but with some modifications, including 35 more environmental measures. The staff alternative also includes numerous measures to benefit resident and anadromous fisheries, in recognition of the cumulative effects that Idaho Power’s mid-Snake and Hells Canyon projects have had on upstream fisheries, including the elimination of anadromous fish runs upstream of Hells Canyon Dam.
Measures specified by FERC staff that would benefit resident fisheries and could contribute to the eventual restoration of anadromous fish upstream of the project include improvements to the adult fish trap at Hells Canyon Dam, and future construction of an adult fish trap at Oxbow Dam.
Several alternatives were examined in the EIS, issued Aug. 31. They included: continuing to operate the project with no changes or enhancements; operating the project as proposed by Idaho Power; FERC staff’s alternative; and the staff alternative with mandatory conditions proposed by federal resource agencies. FERC staff said the mandatory condition alternative was similar to the staff alternative.
It also considered federal takeover of the project, issuance of a non-power license, and project retirement, but concluded �none of these alternatives are reasonable in the context of this proceeding.�