National Program for Inspection of Non-Federal Dams. West Parish Filter Number 3 Dam (MA 00610), Connecticut River Basin, Westfield, Massachusetts. Phase 1 Inspection Report

摘要

West Parish Filter No. 3 Dam is an earthen embankment structure 37.5 feet high and 800 feet long. A side-channel spillway is located at the right abutment. It has a concrete overflow section which is 23.4 feet long. Outlet piping passes beneath the embankment and connects directly to the water treatment plant which serves the City of Springfield, Mass. The dam is situated on a very small (0.07 sq. mi) drainage area, and serves as offstream storage and as a sedimentation basin for water which is piped from other dams. Based on the visual inspection, the dam is judged to be in fair condition. The following deficiencies were observed at the dam: a soft, wet area near the downstream toe; a row of evergreen trees along the downstream toe with some roots penetrating the embankment; rodent holes on the downstream slope; wheel tracks on the crest of the dam; misaligned riprap and loose rock and trees overhanging the spillway; low areas on the top of the dam; and no means of controlling flow at the upstream end of the outlet conduit. The spillway capacity is about 335 percent of the routed test flood outflow of 142 cfs. During the test flood, the freeboard would be 1.9 feet.