Impact basins are effective energy dissipators but are relatively expensive structures (see Figure 8-28).

Stilling basins are hydraulically similar to sills (Figure 8-29). However, they are more expensive in construction and could present serious silting problems. A chief advantage in stilling basins is the lack of a waterfall effect.

Radial energy dissipators are quite effective but extremely expensive to construct and, therefore, not ordinarily justified (Figure 8-30). They function on the principle of a circular hydraulic jump. For a detailed discussion on dissipator types, along with a variety of design methods for velocity control devices, refer to .