The Farmington Reservoir Dam is an earth embankment impounding an unnamed tributary to the Pequabuck River and is reported to have been built in 1895. The dam (including spillway) is 760 feet long and eight (8) feet wide at the top. The dam has a maximum impoundment capacity of 64 acre-feet and is about 8 feet in height from the toe of the downstream slope to the top of the dam. The spillway is a 32 foot long, and 2.8 foot high, concrete, ogee shaped weir. There is no information available on outlet pipes. Based upon the visual inspection at the site and past performance, the dam is judged to be in poor condition. There are areas requiring attention, monitoring, and maintenance such as seeps along the toe of the embankment, erosion on the upstream and downstream slopes, location and operation of outlet and inlet structures and valves, and removal of trees. Peak inflow to the impoundment at the test flood is 315 cfs; peak outflow is 250 cfs with the maximum stage in the reservoir at 383.7, or 1.0 foot below the top of the dam. Based on this information the dam is not expected to overtop at the test flood condition. The spillway capacity with the pool at top of dam is estimated to be 525 cfs which is greater than 100% of the routed test flood outflow.

This flood control project consists of a dam and dike which are earth embankments at 3H:1V with good grass cover and a top width of 12 feet. The dam is approximately 3060 feet long and 31 feet high. The dike is approximately 475 feet long and 28 feet high. The principal spillway consists of a reinforced concrete riser, a 30 inch RCP through the dam and a reinforces concrete impact basin. The emergency spillway is a 130 foot wide grassed earth channel at the eastern end of the dam. The reservoir is normally empty except for a small sediment pool. Based on the visual inspection, review of design information, and past operational performance, the dam and dike are judged to be in GOOD condition. There is some erosion due to vehicle trespass and animal burrows were noted in the embankments. The maximum outflow capacity of the spillways with the water level at the top of the dam is 3580 cfs, which is 185 percent of the test flood outflow.

The Goodwin Dam is an earth and rock embankment with an earth core that is 800 feet long and 125 feet high. It has an emergency spillway, channel, gate house and diversion tunnel. The dam and its appurtenant structures are in good condition. The dam will pass the Probable Maximum Flood (recommended Spillway Design Flood) without overtopping the dam. Some recommended measures to be undertaken by the owner, should include the establishment of metering points for seepage measurement and periodic inspections of the dam. It is not urgent to implement these recommendations.

Whigville Reservoir Dam is an earthen embankment structure with a concrete/boulder core wall. The dam is 460 feet long and has a maximum height of 54 feet. The 40 foot long concrete/boulder spillway is located at the right side of the dam. Slope paving forms the approach to the spillway. The downstream face is mortared stone masonry. Stone masonry training walls form the wasteway section. The outlet works consist of an upper and lower gatehouse each of which connect to submerged concrete intake structures. A 24 inch diameter blow off pipe passes under the wasteway channel to a stone masonry waste pot. The dam is judged to be in generally poor condition. The riprap on the upstream face is in generally good condition. The vertical and horizontal alignment is good. The downstream slope is covered with an extensive growth of trees and brush. Apparent seepage and wet areas were noted near the toe and at both sides of the spillway channel. The concrete parapet walls are in fair condition, with areas of erosion, spalling and deterioration noted. The concrete spillway weir is in poor condition with severely deteriorated concrete. The spillway is not adequate to pass the PMF spillway test flood outflow (7730 CFS) without overtopping the dam. The test flood would overtop the dam by about 4.2 feet. The spillway would pass about 20 percent of the test flood outflow without overtopping the dam.

The dam of the Upper Unionville Reservoir is an earth embankment with a concrete spillway. It is approximately 220 feet long, 23.8 feet high and has a maximum top width of 10 feet. The Unionville Reservoir Upper Dam was probably constructed in 1909. The Town of Avon presently owns and operates the dam and appurtenant structures. The dam is presently used for passive recreation and to fill the lower pond which is used for swimming. Based on the visual inspection and past operational performance, the dam is judged to be in FAIR condition. A wet area was noted at the downstream toe of the western embankment and there was erosion and/or settlement on the downstream face and top of the embankments. The cover of the intake tower is in fair condition and manhole steps in the intake tower are in poor condition. Access to the tower would be difficult during flood conditions. The test flood for this dam is 1/2 the Probable Maximum Flood (PMF). The test flood has an inflow equal to 1020 cfs and an outflow discharge equal to 1020 cfs with a stillwater elevation of 397.2 which will overtop the dam by 0.9 feet. The maximum outflow capacity of the spillway with the water surface at the top of the dam is 100 cfs, which is 10 percent of the test flood outflow.