ABSTRACT
This chapter explores the types of basins for energy dissipation. Rock basins should be used for net drops of less than 30m as problems may occur for deeper basins with failures associated with weak rock formations. A baffle basin involves several basic elements including bottom geometry, plan geometry, wall roughness and discharge variation. Baffle blocks are normally arranged in one or several rows that are orientated perpendicular to the direction of approach flow. Expanding basins are used quite often, as for low-head plants with only partial operation of gates. The geometry of the bucket basin must be chosen in such a way that all discharges produce tailwater levels that fall between the minimum and the maximum elevations. As hydraulic jumps involve zones of separation and high velocity flow, the pressure fluctuations may be significant besides the mean pressure. The choice for the lining of a stilling basin is strongly related to the degree of pressure fluctuation.
