National Program for Inspection of Non-Federal Dams. South Deerfield (MA 00522), Connecticut River Basin, Whately, Massachusetts. Phase 1 Inspection Report

摘要

The dam is a 120 foot long concrete arch dam. It contains a 40 foot long, 28 foot high ogee spillway with provisions for three feet of flashboards, a 32 foot high, 53 foot long concrete non-flow section and an intake structure with manual controls. The visual inspection did not disclose any findings that indicate unsafe condition. The 100 year test flood used has an inflow and outflow of 1400 cfs which would overtop the non-overflow section by 1.8 feet with 3 feet of flashboards in place on the spillway. With 3 feet of flashboards in place, normal operation, the spillway capacity to the top of the dam (elevation 424) is 124 cfs or about 9 percent of test flood outflow. The overtopping of this non-overflow section is not serious since it is of concrete construction and can effectively act as an auxiliary overflow spillway. The dam is in generally good condition. However, the owner should frequently monitor the seepage from joints in the right abutment rock and the contract area between the left abutment and the downstream face. The owner should also repair cracks in the concrete face and monitor the horizontal and vertical construction joints and/or cracks to determine if seepage occurs in the future.