Modeling Gradual Dam Breaches

A simulation model of the gradual failure of an earth dam has been formulated, developed and tested with real-life data. A significant feature of the model is its ability to account for the growth of the breach and the eventual draining of the reservoir. Concepts of water and sediment routing are used in conjunction with a channel geometry descriptor to arrive at a self-contained mathematical model of the breach enlargement and the ensuing flood wave. Unsteady flow elements of the simulation are an implicit numerical solution of the complete Saint Venant equations coupled with a sequential sediment routing technique. This approach provides an increased rational basis for determining outflow hydrographs from postulated earth dam breaches.