Civil Engineering PE

Answer: D - Stilling basins are commonly installed for energy dissipation, scour prevention, and channel erosion control purposes. Stilling basins are used at culvert outfalls to dissipate kinetic energy to prevent or mitigate scour holes and downstream channel erosion. Stilling basins are often a low-cost alternative to other in-stream modifications that can be made to address erosion and ecosystem restoration issues.