National Dam Inspection Program. (PA-474 (PA No Name Number 35), NDI Number PA-00249, PennDer Number 43-50, SCS Number PA-474), Ohio River Basin, Saw Mill Run, Mercer County, Pennsylvania. Phase I Inspection Report,

PA 474 also referred to as PA No Name No. 35 was designed by the U.S. Department of Agriculture, Soil Conservation Service SCS for floodwater detention. The dam consists of a zoned earth embankment, a vegetated earth emergency spillway channel, a riser intake with a 36-inch diameter outlet conduit, and a saddle dike located to the right of the main embankment. The crest length of the main embankment is 1640 feet. The maximum height of the dam at the original steambed is 30 feet. The dam crest is at E1. 1264.3 feet and the top width is 14 feet. The inclination of the upstream face is 2.5H1V Horizontal to Vertical with a 10-foot wide berm at E1. 1242 feet. The downstream slope is 2.5h1V. A filter trench was installed in the downstream prism of the embankment from original Station 492 to 977. A portion of the filter trench is provided with 6-inch diameter filter drainpipe. The two outlets of the filter drainpipes exit into the impact basin approximately 1 foot downstream of the baffle wall. To the right of the main embankment is a small knoll which separates the saddle dike from the main embankment. This knoll consists primarily of sandy silt ML soils and is approximately 540-feet long between the two embankments. The crest length of the dike is 670 feet and the maximum height is 9 feet. The crest width of the homogeneous embankment dike is 14 feet. The inclination of both the upstream and downstream slopes of the dike is 2.5h1V. Author