National Dam Safety Program. Springhill Lake Dam (Inventory Number VA 01906), Roanoke River Basin, Bedford County, State of Virginia. Phase I Inspection Report.
Abstract
Sringhill Lake Dam (formerly Toms Dam) is an earthfill embankment approximately 42 feet high and 400 feet long. The dam, located approximately 5 miles northwest of Bedford, Virginia, is used for recreation. Visual inspection and office analyses indicate deficiencies requiring immediate attention. Using the Corps of Engineers' screening criteria for initial review of spillway adequacy, the 1/2 Probable Maximum Flood (1/2 PMF) 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 1.3 feet with an average critical velocity of 2.8 f.p.s. Total duration of dam overtopping would be approximately 9.4 hours. The dam and reservoir are capable of controlling only 25 percent of the Probable Maximum Flood (PMF), and are therefore considered inadequate. The combination of the instability of the downstream embankment and the inadequate spillway capacity represents a higher potential for dam failure during overtopping of the embankment crest. The area of seepage and sloughing on the downstream embankment around the outlet pipe was the most serious stability condition noted during the field inspection. The dam is assessed as unsafe, emergency.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1979
- Accession Number
- ADA077471
Entities
People
- James A. Walsh