National Program for Inspection of Non-Federal Dams. Coes Reservoir Dam (MA 00120), Blackstone River Basin, Worcester, Massachusetts. Phase I Inspection Report.
Abstract
Built in 1865, Coes Reservoir Dam is an earthfill dam with a 700-foot long and 20-foot high embankment. The Coes Knife Company buildings are located immediately downstream of the dam, and grinding grit fill from the company has been placed on the dam over the years. A broad-crested spillway is located near the north abutment. The concrete weir is 38.5 feet long with a crest elevation (E1) of 501. Normal discharge flows over the weir, down a stone-lined channel, and into Lower Coes Pond. There is an abandoned 36-inch diameter intake conduit which has been sealed off at the upstream face of the dam. Discharge from the conduit was into a tailrace channel which is located at the toe of the dam and leads to the spillway discharge channel. The following visible signs of distress indicate a potential hazard at the site; erosion and lack of protection on the steep upstream face of the dam; deterioration of the concrete and stone training walls of the spillway; cracking and collapse of the concrete side channel in the discharge channel; seepage from the upstream wall of the tailrace channel and north wall of the discharge channel; and a dense growth of brush and trees on the dam embankment and the downstream areas. An inflow test flood of 10,000 cfs adjusted for surcharge storage results in an outflow of 8,500 cfs. This will overtop the main dam by about 3.4 feet. The spillway is inadequate since it can discharge only 17 percent of the test flood before the dam is overtopped.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1978
- Accession Number
- ADA145066
Entities
Organizations
- New England District, U.S. Army Corps of Engineers