Predicting Peak Outflow from Breached Embankment Dams

From 1977 to 1995, a series of regression relations were developed to predict the peak discharge from breached embankment dams. In 2008, a study was conducted to review previous investigations, expand the working database of dam failures, and evaluate the appropriateness of the existing relationships. Forty-four case studies were collected and added to the existing database, resulting in a composite database of 87 case studies. The composite database was evaluated and a statistical analysis was performed using linear, curvilinear, and multiple-regression techniques. Enhanced simple- and multiple-regression expressions were developed to predict peak-breach discharge as a function of the height and/or volume of water behind the dam. A comparison of selected historical and newly derived expressions indicates that three previously developed relations remain valid for conservative peak outflow predictions. Newly developed expressions relating peak outflow as a function of the height (H) and/or volume (V) of water behind the dam at failure provide encouragement for practical applications where a best estimate of the peak-breach discharge is desired.