In this paper, genetic programming (GP) was used to simulate outflow hydrograph from earthen dam breach. The required data for
the modeling were collected from literature, new experimental tests, and a physically based model. A number of homogeneous cohesive and
noncohesive embankments were constructed in the flume and breached by overtopping flows. In the experiments, 40 embankments were
constructed and tested in various sizes with different materials. The results demonstrate that the results of the GP method are in good agreement with the observed values. The model was tested for a case study (Teton Dam). In addition, an experimental-based broad-crest weir
(EXBCW), a lumped model for calculating the peak outflow discharge due to an earth dam breach, was proposed on the basis of the
governing equation of broad-crest weir outflow and experimental data. Finally, the results of the EXBCW model were compared with
the observed data and results of empirical and GP-based methods.