National Program for Inspection of Non-Federal Dams. Kelleys Falls Dam (NH 00299, NHWRB no. 150.02). Merrimack River Basin, Manchester, New Hampshire. Phase I Inspection Report.
CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV
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Kelleys Falls Dam is a run of the river type dam, with an overall length of 503 feet. Visual inspection of the dam indicated that the dam is in poor condition. The inspection revealed a number of leaks through the mass concrete spillway section, considerable loss of concrete from the spillway section, seepage around the concrete wall on the right side of the dam, and general deterioration of concrete on the abutments and hydro-building. Based on the intermediate size of the dam and the significant hazard classification and in accordance with Corps of Engineers guidelines, the test flood is one half the Probable Maximum Flood PMF or 55,900 cfs. The one half PMF outflow overtops the dam by 6.8 feet. With the water level at the top of the dam, the spillway will pass 38 percent of the test flood outflow. It is recommended that the owner engage a qualified engineer to make thorough investigation of the condition of the foundation of the spillway section of the dam, investigate the structural stability of the spillway section and ways to increase the spillway capacity. Also, the owner should remove the flashboards on the dam immediately. Additional keywords Merrimack River Basin, Manchester, and New Hampshire.
- STRUCTURAL PROPERTIES
- VISUAL INSPECTION
- ARMY CORPS OF ENGINEERS
- NEW HAMPSHIRE
- Hydrology, Limnology and Potamology
- Civil Engineering