Dam Break for the Dalles Dam

The Dalles Dam consists of a powerhouse, a concrete spillway, a navigation lock, concrete non-overflow sections, an earth-fill embankment on the Washington shore, a rock-fill embankment on the Oregon shore, and fish passage and appurtenant facilities. This dam is one of the largest navigation dams in the United States; it is approximately 8,735 feet in length and over 200 feet high. This paper will discuss the hydrologic and hydraulic approaches for the dam failure analysis. It will also focus on the breach characteristics, type of failure and non-failure simulations that were used in the model analysis. This paper will also spotlight the water resource engineering assumptions and techniques that were used in the HECRAS and HECGeoRAS models.