National Dam Inspection Program. Graceton Dam (NDI ID Number PA-279, DER ID Number 32-25) Ohio River Basin, Unnamed Tributary of Two Lick Creek, Indiana County, Pennsylvania. Phase I Inspection Report

摘要

Graceton Dam consists of an earth embankment approximately 250 feet long with a maximum height of approximately 26 feet from the downstream toe. The crest width is approximately 10 feet. A 10-foot-wide berm is located on the downstream slope at about midheight of the embankment. The downstream slope of the embankment is approximately 1.5H to 1V above the berm and 2.5H to 1V below that level. The flood discharge facilities for the reservoir consist of a concrete overflow structure located on the left abutment (looking downstream). The overflow section is approximately 15 feet wide and 3 feet deep and discharges onto an approximately 30-foot-long concrete chute. According to the previous inspection reports, the outlet facilities consist of two cast-iron pipes 4 and 6 inches in diameter. the location of the pipes and the manner in which flow through these pipes is controlled is unknown. In the design drawings, flow through these pipes is shown to be controlled by valves located in a valve chamber on the downstream side of the dam. However, this valve chamber could not be located at the site during this inspection. As it presently exists, the dam has no functional emergency drawdown facilities. (Author)