The dam at Deep River Reservoir is a zoned earth embankment approximately 900 feet long, 62 feet high with an average crest width of 20 feet. It was originally constructed in 1926, 7 and raised in 1971, 2 to its present configuration. It is owned by the City of Norwich, Connecticut and operated by the Department of Public Utilities as the main surface water supply of the City. The dam has an agee overflow spillway at the right abutment. The spillway is a converging chute type with a drop to a stilling basin at the toe of the dam. The outlet works and control tower are centered on the embankment and discharges from the tower's wet well flow through a reinforced 42 inch diameter condiut beneath the dam. An earth embankment dike 240 feet long in an adjacent cove of the reservoir contains an erodable fuse plug emergency spillway. As a result of the visual inspection and the review of available data regarding this facility, the dam is considered to be in GOOD condition. To assure the long-term performance of this structure, several items of concern require attention: modifications need to be made to the existing relief well monitoring system in order to more accurately record the seepage flow, a localized erosion immediately upstream of the left abutment of the dam must be repaired, and vegetable growth in the downstream channel of the emergency spillway should be removed. The maximum outflow capacity of the spillway under a stillwater condition is equal to 18,860 CFS which represents more than 100 percent of the test flood.

Fairview Reservoir Dam is an earth dam with a masonry core wall constructed around 1868 and is used today as a standby water supply for the city of Norwich. The dam has a maximum height of 28.0 feet and is approximately 520.0 feet long, with a top width of 27.0 feet. There are four auxiliary dikes at the north end of the reservoir; all four dikes are earth embankments of the same construction and similar to the main dam. The outlet spillway is located in the Northwest Dike and is 27.0 feet long. The dam is considered to be in FAIR condition. Several visible signs of distress which indicate potential hazards are: seepage at two spots at the downstream toe of the dam, seepage through the roof of the valve chamber, rotting stumps on the main embankment, trees and shrubs on the downstream face of the main dam and both faces of all the dikes, structural deterioration of and seepage from under the spillway, rusted outlet conduits at the valve chamber with valves frozen in the open position allowing constant pressurized outlet pipes to pass through the embankment, and a general lack of regular maintenance. The maximum spillway discharge is 648 cfs, or abut 48 percent of the test flood outflow.

Taftville Reservoir No. 2 Dam is a zoned embankment about 667 ft. long with a concrete core wall, is 16 ft. wide at the crest, and has a maximum height of about 30 ft. It has a combined drop inlet spillway and outlet tower structure. The outfall from the drop inlet is a 16 in. dia. pipe and the outlet pipe is a 12 in. dia. A trapezoidal notch in the crest of the dam serves as an auxiliary spillway. Maximum storage capacity of the reservoir is 110 acre-feet and the drainage area is 69 acres. The dam appears to be in good condition. The crest and downstream slope are covered with brush growth and there is some local displacement of rock fill and riprap. The outlet tower structure has been subject to vandalism, including demolition and removal of the concrete block tower house. Previous inspection reports noted seepage at the toe of the embankment near the 16 in. dia. spillway outfall pipe, but with the reservoir empty no seepage was evident on the date of this inspection. The drop inlet and auxiliary spillways are together adequate to pass the selected test flood of 1/2 PMF without overtopping the dam.