National Program for Inspection of Non-Federal Dams. Aspetuck Reservoir Dam (CT 00021), Saugatuck River Basin, Easton, Connecticut. Phase I Inspection Report

摘要

The Aspetuck Reservoir Dam is an earth embankment which is 1,160 feet long and 11 feet high with a concrete gravity spillway which is 500 feet long. The earth embankment has a core wall and it and the spillway are built on two rows of wooden sheet piling that extends 16 feet into the ground. There is a 36-inch low level discharge pipe to the downstream area and a 24-inch low level discharge pipe into an adjacent 8-foot diameter conduit. This conduit is a diversion into another reservoir with an independent watershed. The drainage area is 17.6 square miles and the reservoir has 311 acre-feet of available storage. The assessment of the dam is based on visual inspection, available drawings, 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, spillway and around the abutments and several areas of the spillway where concrete has spalled and the joints are in poor condition. The dam is classified as small and has a significant hazard potential in accordance with guidelines established by the Corps of Engineers. The test flood outflow for this dam is 3,235 cfs which corresponds to the 100-year flood. The spillway capacity is 11,300 cfs or 3.5 times the test flood outflow. The test flood outflow will flow over the spillway by 1.4 feet.