This paper responds to a strategy in the Council’s 2014 Columbia River Basin Fish and Wildlife Program addressing mitigation of the impacts of hydropower dams on anadromous fish in areas where dams block fish passage to historic habitat. The first phase of the three-phase approach calls for studies and evaluations to inform what is known generally about fish passage and specifically about the quality of the habitat in the blocked waters of the Upper Columbia above Chief Joseph and Grand Coulee dams. Neither dam was built with fish-passage facilities.
The habitat evaluation is being conducted for the Council by the Spokane Tribe of Indians. In this paper, which can be viewed as a corollary to that evaluation, Council staff evaluates information from passage studies at Chief Joseph and Grand Coulee, and at other dams where fish passage has been studied or completed. Included in the evaluation are dams in Washington and Oregon, on the border of Oregon and Idaho, and in California and Pennsylvania. In order to better understand each location, staff compiled standardized information into case studies, summarizing information gleaned from design documents, annual reports, and from personal communications with project staff.
The paper explores six themes that could apply in planning and providing fish passage at high-head dams such as Chief Joseph and Grand Coulee:
The paper addresses high-head dam passage for both adult and juvenile fish and recommends that fishery managers working on and studying passage should consider the following: