An energy client required the development of an operational analysis of extreme floods for the a reservoir in Wyoming. The operational analysis was intended to define alternative summer reservoir target levels that would allow greater flexibility in flood control operations, thereby reducing the possibility of overtopping and activating the dam’s fuse plug. An analysis of downstream dam break flood routing was also required to demonstrate that the project would not unduly increase flood risk.
Role / Services: WSE provided a range of technical analyses including flood frequency analyses, development of reservoir design inflow hydrographs, reservoir operations modeling, analysis of the potential for breaching of the spillway fuse plug, development of a reservoir rule curve, and downstream hydraulic routing using HEC-RAS.
Outcome: WSE concluded that earlier evaluations of the downstream flood routing may have been overly conservative and that with minor modifications to project operations the potential for increased flood risk in the downstream corridor could be minimized without changes to the physical infrastructure of the dam.