National Dam Safety Program. Spring Valley Lake Dam (Inventory Number VA 77002), Roanoke River Basin, City of Roanoke, Virginia. Phase I Inspection Report.
Abstract
The Spring Valley Lake Dam is an earthfill structure about 450 feet long and 23.9 feet high with a private paved roadway traversing the entire dam. The dam is owned and maintained by Spring Valley Lake Homeowners Association. The dam is classified as a small size with a significant hazard classification. The principal spillway is an 8-inch cast iron pipe drop-inlet that passes through the dam at low level. The secondary spillway is three 36-inch corrugated metal pipes at the right abutment. The emergency spillway is an open channel cut at the left abutment which is also a low point in the private paved road. The reservoir is used for recreation. 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 spillways will pass 29 percent of the PMF 0r 58 percent of the SDF without overtopping the crest of the dam. The SDF will overtop the dam by a maximum 0.25 feet, reach an average critical velocity of 3.4 feet per second and flow over the dam for 1 hour. Flows overtopping the dam during the SDF are not considered detrimental to the embankment. The spillways are adjudged inadequate but not seriously inadequate. The visual inspection revealed no apparent problems and there are no immediate needs for remedial measures. A stability check is not required. Maintenance is performed by the owners. However, there is no regular maintenance operations program or warning system.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1980
- Accession Number
- ADA103505
Entities
People
- James A. Walsh
Organizations
- Norfolk District, U.S. Army Corps of Engineers