National Program for Inspection of Non-Federal Dams. Canoe Brook Lake Dam (CT 00082) and Canoe Brook Lake Dikes (CT 00081), Connecticut Coastal Basin, Trumbull, Connecticut. Phase I Inspection Report

摘要

The project, built in the 1870's, consists of an earthfill dam, a spillway and two earthfill dikes. The dam is approximately 360 feet in length, 12 feet wide at the crest and 33 feet above the streambed of Canoe Brook. The dikes are located at the south shore of the lake approximately 1200 feet southeast of the dam. The East Dike is 300 feet long, 9 feet high and 50 feet wide at the crest. The West Dike is 300 feet long, 16 feet high and 25 feet wide at the crest. The spillway is a natural watercourse located 300 feet northwest of the dam. There are two dry laid stone walls which define the spillway but there is no spillway weir. The outlet is located at the dam and consists of a 48 inch cylindrical pipe which acts as the gate structure for the 30 inch low-level outlet pipe. Based upon the visual inspection at the site and past performance, the project is judged to be in fair condition. No evidence of structural instability was observed in the dam embankment, dike embankments or appurtenant structures. There are areas at the dam, dikes and spillway which require maintenance and monitoring. These areas include seepage at the toe of the dam and west dike, trees and brush on the slopes of the dam and dikes, deterioration of the riprap slope protection and obstructions in the spillway approach channel. The spillway capacity with the lake level to the top of the dam is 3150 cfs, which is equivalent to 112% of the routed test flood outflow.