National Program for Inspection of Non-Federal Dams. Willimantic Reservoir Dam (CT 00198), Thames River Basin, Mansfield-Windham, Connecticut. Phase I Inspection Report.
CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV
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Willimantic Reservoir Dam is a stone masonry and conrete gravity dam with a full crest spillway constructed about 1885. The dam has a maximum height of 29 feet and is approximately 491 feet in length. The stone masonry and concrete spillway has a total crest length of about 491.0 feet and is divided into two distinct sections that have a difference in elevation of 1.2 feet. The dam is considered to be in GOOD condition. Deficiencies include indication of overtopping potential, limited discharge capacity of the spillway and outlet works, inoperable low level outlet through the spillway, and spalling of the downstream face of the left section of the spillway. The test flood outflow for Willimantic Reservoir Dam is equal to 106,000 CFS 635 CSM when Mansfield Hollow Reservoir upstream is full and 89,000 CFS 533 CSM when it is empty. With Mansfield Hollow Reservoir full, the PMF will produce overtopping at Willimantic by 8.6 feet and empty by 6.7 feet. For the purposes of this study, Mansfield Hollow Reservoir was considered empty for the one-half PMF event and no overtopping would result at Willimantic. The maximum spillway discharge at Willimantic Reservoir Dam is equal to 38,125 CFS.
- Hydrology, Limnology and Potamology
- Civil Engineering