Spillways

Spillways

All embankment ponds require one or more spillways for overflow water. It is common to have a vegetated earthen emergency spillway around one end of the dam for flood flows and a pipe spillway through the dam for normal flows. The stand pipe or trickle tube should be installed a foot or more below the level of the earthen emergency spillway. Anti-seepage collars are needed along the pipe through the dam to help prevent the pipe from washing out. A trash guard should be installed on the stand pipe for safety purposes and to prevent clogging with debris.

The design capacity and type of materials needed for both the emergency and pipe spillways are variable for different pond sizes and watersheds. Technical advice should be obtained from the Natural Resources Conservation Service or a civil or agricultural engineer for this portion of the pond design.