Abstract: The exits of tailrace of Shuibuya Hydropower Plant are located very clolse to the downstream energy-dissipater. The surge wave near the exits of the tailrace is fairly large during the flood-releasing period, and the deposition at the same region is rather serious under small discharge cases. Through comparing and optimizing the test results of different arrangement schemes at a 1∶100 scale hydraulie model, a recommended energy dissipator with stepped narrow-slot ski-jump buckets is worked out, which can solve all abovementioned problems, and thus has been accepted by the desigh. This scheme achieves better effect in the aspects of raising of the elevation of scour pit and reducing the wave height because itconforms fairly well to local geography and river regime downstream the dam and can make use of the energy dissipation of water jetting in air and of water body in river.

Key words: lowering wave and decreasing deposition , tailrace of hydropower plant , Shuibuya Project