National Program of Inspection of Non-Federal Dams, Tennessee. Grand Valley Dam Number 1 (Inventory Number TN 06924) Hatchie River Basin, near Hickory Valley, Hardeman County, Tennessee. Phase I Investigation Report

摘要

Grand Valley Dam No. 1 is located in Hardeman County, Tennessee several miles east of Hickory Valley, Tennessee and is an earth fill embankment 37 feet high and 1800 feet long. The crest width is 26 feet. Facilities for discharge from the reservoir are located near the south abutment and consist of a concrete service spillway 11 feet by 8 feet with two 9.0 foot by 0.83 feet openings and a 42 inch CM pipe barrel through the dam and an emergency spillway constructed as a low area in the top of the dam. The emergency spillway has gentle side slopes and a 50 foot wide bottom section. The entrance and exit slopes are 1V on 3H on the upstream slope and 1V on 4H on the downstream slope. No protection is provided for the exit slope. The upstream slope is vertical from the waterline for approximately two feet. The slope from that point to the crest is one vertical on three horizontal. The downstream slope is generally one vertical on four horizontal. Both the upstream and downstream slopes have ineffective vegetation. The dam is in the intermediate size category and has a downstream hazard potential classification of high by the USCE and 'I' by the State of Tennessee. On the basis of hydraulic analysis, the dam has flood storage (572 acre-feet) and spillways inadequate to safely pass the Probable Maximum Flood (PMF).