What are the methods for energy dissipation below spillways?

Energy dissipation methods: (1) Stilling basin - hydraulic jump confined in basin with floor blocks and end sill to force jump (USBR Type I-IV designs), (2) Flip bucket/ski jump - throws jet away from dam, energy dissipated in plunge pool, (3) Roller bucket - submerged bucket creates reverse roller, (4) Stepped spillway - energy dissipated over multiple steps, (5) Impact-type - flow impacts floor or walls. Selection depends on tailwater conditions, space availability, downstream erodibility, and discharge magnitude. Proper design prevents erosion that could undermine dam.