National Program for Inspection of Non-Federal Dams. Lake Naraneka Dam (CT 00223), Connecticut Coastal Basin, Ridgefield, Connecticut. Phase I Inspection Report.
CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV
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The Lake Naraneka Dam, constructed in 1937 for recreational purposes, is a 156-foot-long and 18-foot-high concrete gravity dam which is arched in plan. The dam is 4 feet wide at the crest has a 0.1H1V sloped upstream face and a downstream face which is inclined at approximately 0.65 H1V. The spillway is incorporated into the left side of the dam. The 11-foot-long spillway, located about 30 feet from the left abutment, discharges into a 60-foot-long stone paved channel. Discharge from the site may also pass through the manually controlled 14-inch diameter low level outlet of the 2-inch and 8-inch diameter conduits that supply and drain the small masonry pool at the downstream toe of the dam. The visual inspection of the dam indicated that the structure is in fair condition. Seepage and wet areas were observed on the downstream face of the dam. Extensive efflorescence, cracking and spalling of the concrete was noted at many areas on top, upstream, and downstream faces of the dam. The Lake Naraneka Dam has a top of dam storage capacity of 675 acre-feet ac-ft and is approximately 18 feet in height. The capacity of the spillway, with the water surface at the top of the dam, is 215 cfs or 43 percent of the routed test flood outflow. As a result, the dam will be overtopped by 0.7 feet.
- Hydrology, Limnology and Potamology
- Civil Engineering