National Dam Safety Program. Johns Creek Dam Number 1, Inventory Number VA-04502. Craig County, State of Virginia. Phase I Inspection Report.
Abstract
Johns Creek No. 1 Dam is a zoned, earthfill dam approximately 1500 feet long and 62 feet high. The dam, located approximately 21 miles southwest of New Castle, Virginia, is used for flood control. Visual inspection and office analyses indicate no deficiencies requiring emergency attention. Using the Corps of Engineers' screening criteria for initial review of spillway adequacy, the 1/2 Proabable 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 1.6 feet with an average critical velocity of 3.4 f.p.s. Total duration of dam overtopping would be approximately 5.8 hours. The spillway is capable of passing only 25 percent of the PMF and is therefore judged as inadequate. The dam and appurtenant structures were found to be in generally good overall condition. No conditions indicating embankment instability were detected during the field inspection and office analyses.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1979
- Accession Number
- ADA077464
Entities
People
- James A. Walsh