A critical review of fish passage facilities suitable for excluding anadromous salmonids and clupeids from hydroelectric turbine intakes identified four potential methods. A floating louver array in conjunction with surface spill from an ice and trash sluiceway located near the turbine intakes was considered to have the best chance of diverting 75% or more of the juvenile migrants from the turbine intakes. A prototype floating louver device was designed, built, and tested at a 5.5. m deep canal with a flow of approximately 150 m3/s. The device was based on the observation that downstream fish migrants are found near the water surface. Hence, only the top 2.4 m of water depth was screened. The louver array was 176 m long and guided between 80 to 100% of radio tagged Atlantic salmon smolts. Further testing of the device with anadromous clupeids is scheduled for the fall of 1990.