Scour

Eagle Nest Dam - Eagle Nest, New Mexico

E&H evaluated the scour potential of the rock foundation on the downstream side of the Eagle Nest Dam when subject to overtopping during the PMF. The methods used to evaluate site conditions were the Erodibility Index Method (EIM) (Annandale 1995), the Comprehensive Fracture Mechanics approach (CFM) and the Dynamic Impulsion Method (DIM). Scour potential of the existing spillway on the left bank was assessed by inspecting the rock and judging its potential vulnerability. Based on the information that was generated during the jet scour analysis we assessed the spillway performance and that of its discharge area without detailed calculation. E&H determined that scour potential at the base of the dam during an overtopping event could occur in two possible modes; instability of the rock on the left abutment, and scour potential by fatigue of the rock foundation in the downstream impingement zone.

Engineering - Science - Sustainable Solutions