National Dam Safety Program. DiGiulian Dam (Inventory Number VA 06102), Shenandoah River Basin. Fauquier County, Commonwealth of Virginia. Phase I Inspection Report.

DiGiulian Dam is an earthfill embankment 29.9 feet high and 281 feet long. The principal spillway is a corrugated metal pipe riser located near the center of the dam. Using the Corps of Engineers' screening criteria for initial review of spillway adequacy, the 100-year flood was selected as the spillway design flood (SDF). The SDF was routed through the reservoir and found to overtop the dam by a maximum depth of 0.7 foot with an average critical velocity of 2.9 f.p.s. Total duration of dam overtopping would be approximately 0.8 hours. Overtopping flows are not considered to be seriously detrimental to the embankment. The spillway is capable of passing up to 84 percent of the SDF or 12 percent of the Probable Maximum Flood (PMF) without overtopping the dam. The spillway is adjudged as inadequate, but not seriously inadequate.