National Dam Safety Program. Williams Dam (Inventory Number VA 14111). Staunton River Basin. Patrick County, Virginia. Phase I Inspection Report

摘要

Williams Dam is an earthfill dam about 250 feet long and 28.6 feet high. Based on criteria established by the Department of the Army, Office of the Chief of Engineers (OCE), the Spillway Design Flood (SDF) is the 1/2 PMF. The emergency spillway will pass 11 percent of the PMF or 22 percent of the SDF without overtopping the crest of the dam. The SDF will overtop the dam by a maximum of 2.15 feet, reach an average critical velocity of 5.6 feet per second and flow over the dam for 3.75 hours. Flows overtopping the dam during the SDF are not considered detrimental to the embankment. The spillway is adjudged inadequate but not seriously inadequate. The visual inspection revealed no apparent problems or remedial measures in need of immediate attention. A stability check of the dam is not required. It is recommended that a formal maintenance program and warning system be established.