National Program for Inspection of Non-Federal Dams. Butterworth Dam (CT 00122), Connecticut Coastal Basin, Hamden, Connecticut. Phase I Inspection Report.
CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV
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The Butterworth Dam, built in 1963 to impound water for recreational use, is an earth embankment measuring approximately 215 feet in length and 15 feet high, with a maximum impoundment capacity of 113 acre-feet. There is a 26 foot long by 5 foot deep concrete spillway located within the embankment about 40 feet from the left abutment. An 18 inch ACCMP low-level outlet extends through the left side of the spillway and discharges to the spillway stilling basin. An 80 foot long grass lined emergency spillway is located at the right end of the dam. This spillway is actually a section of embankment which is 2 feet lower than the top of the dam and has a downstream slope that is flatter than the remaining portion of embankment. The spillway capacities for the principal and emergency spillways with the pond level at the top of the dam are 970 cfs and 665 cfs, respectively. The combined spillway capacity at these conditions is 1635 cfs, which is greater than 100 of the routed test flood outflow. The combined spillway capacity with the pond level to the top of the headwalls elevation 120.0 is 935 cfs, which is 75 of the routed test flood outflow. Based upon the visual inspection at the site and past performance of the dam, the project is assessed as being in fair condition. There are items requiring investigation, repair, maintenance and monitoring such as cracking of the concrete training walls at the principal spillway, brush and erosion on the slopes, the lack of proper riprap protection on the upstream slope and a wet area at the toe of the dam.
- Hydrology, Limnology and Potamology
- Civil Engineering