Dear Michael Bätscher :

You need to route the model with out any dam failure by setting the value for "Water Surface Elevation at Time of Failure" in the Dam Description to a very high number. Then, observe the elevation of the water at each of the dam, and determine at what elevation the water is when you want the dam to fail. Then, change the value for "Water Surface Elevation at Time of Failure" to be the observed water surface elevation.

If you have any additional questions or need any further information, please contact me again.

Sincerely,

Chris E. Maeder, M.S., P.E.
Senior Technical Engineer
chris.maeder@bossintl.com