The dissipation of energy in a stilling basin is often increased by the use of blocks and baffles which create additional eddies and turbulence in the flow. These are beneficial in decreasing the specific energy of the flow and in lowering depths downstream of the hydraulic jump. However it must be appreciated, by students and teachers alike, that dissipation of additional energy will increase downstream velocities. Although this should be obvious from a specific energy diagram the effects may easily be overlooked. This brief paper helps to clarify the extent of the velocity increase and provides quantitative data showing the relationship between velocity increase and specific energy decrease.
