Accession Number:

ADA143447

Title:

National Program for Inspection of Non-Federal Dams. Lake Konomoc Dam (CT 00152), Niantic River Basin, Waterford, Connecticut. Phase I Inspection Report.

Descriptive Note:

Corporate Author:

CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV

Personal Author(s):

Report Date:

1979-06-01

Pagination or Media Count:

147.0

Abstract:

Lake Konomoc Dam is an earthfill dam with a concrete core, about 540 ft. long, with a maximum height of about 23 ft. The dam is abutted by an earthfill dike at each end. Two other earthfill dikes form the lake closure Davis Pond Dike at the north end of the lake, and Great Swamp Dike located on the northeast shore of the lake. A double side channel, U-shaped spillway, constructed of reinforced concrete, is located at about the mid-point of the dam. A pumping station, located just east of the dam has a normal capacity of about 6 to 8 cfs 4 to 5 mdg and a maximum capacity of 17 to 18.5 cfs 11 to 12 mgd with all facilities operating. There are no other outlet facilities for draining the lake. Lake Konomac is utilized as a water storage facility for the City of New London. It is about 10,800 feet long and has a surface of 299 acres at spillway crest level. The drainage area is 1.38 sq. mi. 883 acres and the maximum storage to top of dam is 4,660 acre-feet. The dam and dikes are judged to be in generally fair condition owing to the absence of adequate dewatering facilities. The spillway is adequate to pass the PMF test flood inflow of 4,500 cfs without overtopping the dam or dikes the maximum outflow being 1,120 cfs at water surface elevation 189.7 MSL. The spillway capacity at the top of dam, elevation 191.0 MSL, is 1,845 cfs.

Subject Categories:

  • Hydrology, Limnology and Potamology
  • Civil Engineering

Distribution Statement:

APPROVED FOR PUBLIC RELEASE