STATUS OF FISH PASSAGE FACILITIES AT NONFEDERAL HYDROPOWER PROJECTS

The status of direct mitigation practices for fish passage was assesse d as part of an ongoing, multi-year study of the costs and benefits of environmental mitigation measures at nonfederal hydroelectric power p lants. Information was obtained from the Federal Energy Regulatory Com mission, hydropower developers and state and federal resource agencies involved in hydropower regulation. Fish ladders were found to be the most common means of passing fish upstream; elevators/lifts were less common, but their use appears to be increasing. A wide variety of miti gative measures, including spill flows, narrow-mesh intake screens, an gled bar racks and light- or sound-based guidance measures, is employe d to prevent fish from being drawn into turbine intakes. Performance m onitoring and detailed, quantifiable performance criteria were frequen tly lacking. Fifty-two of the 66 projects (82%) with operating downstr eam fish passage measures had no performance monitoring requirements; 50 of 71 project operators (70%) indicated that no performance objecti ves had been specified for the mitigative measures. We found that comp rehensive field studies needed to evaluate the effectiveness of fish p assage devices have been rare.