National Program of Inspection of Non-Federal Dams, Tennessee. Cane Creek Dam Number 19 (Inventory Number TN 09705), Hatchie River Basin, Near Ripley, Lauderdale County, Tennessee. Phase I Investigation Report

摘要

The crest undergoes little change in elevation and has a fairly constant width but ruts from vehicular traffic are predominant along much of the surface. The downstream slope of the dam is traversed by cattle trails nearly paralleling one another at different elevations from the toe to the dam crest. Some vehicular traffic has apparently also been occurring on the slope in the area of the principal spillway outlet. The upstream slope of the dam has been sloughed off below elevation 352 along most of the length of the dam. The embankment is reasonably well grassed and free of undesirable vegetation. There are some wet areas along the downstream toe but they are apparently pooled surface runoff and not the result of seepage. Because the reservoir was empty during the inspection, any active seepage flow that may normally occur did not appear, but no indications of a previous seepage flow were observed on the slope. The principal spillway consists of a reinforced concrete riser feeding a 156 foot, 30 inch diameter reinforced concrete culvert. The emergency spillway is an uncontrolled saddle type trapezoidal earthen channel at the left end of the dam. It has an 80 foot base, 1V:4.6H side slopes, and 2.1 feet of available head. OCE guidelines recommend that high hazard dams of intermediate size pass the full Probable Maximum Flood. Hydraulic and hydrologic analysis reveal that the dam will be overtopped by a maximum of 2.4 feet for 7.2 hours (AMC II) under the influence of this storm. The dam is given a condition classification of 'unsafe nonemergency' because of its seriously inadequate spillway.