National Program for Inspection of Non-Federal Dams. Black Pond Dam (CT 00135), Quinnipiac River Basin, Meriden, Connecticut. Phase I Inspection Report

摘要

Black Pond Dam is a stone masonry and earth embankment structure approximately 100 feet long and 26 feet high with a 25-foot wide paved road (Birdsey Avenue) on the crest. A majority of the downstream embankment consists of a vertical stone masonry face. The 14-foot wide spillway is a 14-foot by 3-foot concrete culvert under the road at approximately the center of the dam. There is a mortared stone gate inlet structure that controls a 20-inch cast iron water main that passes through the base of the dam. The water main connects into the City's distribution network, and is used only for emergencies. There is no low-level discharge. The pond is presently used for recreation. The drainage area is 1.2 square miles and the reservoir has approximately 353 acre-feet of storage capacity. The assessment of the dam is based on the visual inspection, past operational performance and hydraulic/hydrologic computations. The dam is judged to be in fair condition with several areas that require attention. These areas include seepage through the dam, missing mortar in the downstream face, trees on the embankments as well as along the toe of the dam and the lack of a low-level discharge pipe. The test flood for this dam is 1/2 the PMF and is calculated to be 560 cfs. The spillway capacity at the top of the dam is 250 or 45 percent of the test flood outflow. The test flood outflow will overtop the dam by 1.1 feet.