Lake Winnemaug Dam is an earth embankment approximately 500 feet long with a maximum height of about 15 feet. The upstream slope of the embankment is approximately 1H:1V and the downstream slope is about 1.5H:1V. The top of the dam is about 20 feet wide and it is a paved road. The overflow drop spillway is located about 100 feet from the right abutment and consists of an 18.5-foot long concrete weir, a cascading step section and a 4-foot high by 10-foot wide culvert through the embankment. The original purpose of the dam is unknown; however, the lake is currently used for recreation purposes. The peak test flood inflow for Lake Winnemaug Dam is 3,460 cfs. The routed test flood outflow of 2,010 cfs overtops the dam by about 0.8 feet. The spillway is capable of discharging 770 cfs or about 38 percent of the routed test flood outflow prior to overtopping of the dam. A breach of the dam would result in a 7.8-foot increase in the stream depth (3.8 feet above the channel banks) at the initial downstream damage area. The dam appears to be in poor condition. Numerous structural deficiencies, such as slope failures, seepage, and toe erosion were observed during the visual inspection. The embankment is overgrown with brush and trees and contains a number of rodent holes. The reservoir cannot be drained in an emergency because the outlet pipe control valve is inoperable.

The Pin Shop Pond Dam consists of an earth embankment with a 100 fokot long stone masonry overflow spillway located at the left end of the dam. Teh dam has a total length of 400 feet and a miximum height of 23 feet. The outlet works located to the left of the spillway consistk of an intake sluice gate which discharges into a stone masonry and concrete structure. A 16-inch gate valve drains the structure and discharges downstream of the spillway, A conduit to a downstream industrial complex is plugged with concrete. Based on the visual inspection, the dam is judged to be in poor condition. The future integrity of the dam can be affected by the lack of slope protection on the upstream slope, and continued erosion of the upstream and downstream slopes; trees on the embankment; continued undermining of the spillway apron; vegetation growing in open joints of the stone masonry training walls; the poor condition of the outlet works; and indagequate spillway capacity. The spillway has a capacity of 3,200 cfs and is capable of discharging 34 percent of the Test Flood outflow.

The Merriman Pond Dam consists of an earth embankment with a maximum height of 16 feet, a top width that varies from 30 to 80 feet, and an overall length of 500 feet, including a 12.5 foot long overflow spillway located approximately 150 feet from the right end of the dam. A paved road extends the entire length of the dam with a steel beam and concrete bridge crossing the spillway discharge channel. The outlet works consist of an 8-inch low level outlet or blowoff located to the left of the spillway and controlled by a downstream valve. The dam impounds Merriman Pond which is used as the water supply for turf irrigation of an adjacent golf course. Based on the visual inspection, the dam is judged to be in poor condition. Features that could affect the future integrity of the dam are continued erosion of the upstream and downstream slopes, seepage through the embankment, the presence of trees, stumps and brush on the downstream slope and deterioration of the spillway wing walls. The Test Flood inflow of 680 cfs results in a routed outflow of 345 cfs that overtops the dam by 0.1 feet. The spillway capacity with the water level at the top of the dam is 330 cfs and is equal to 96 percent of the Test Flood routed outflow.

The Black Rock Pond Dam consists of an earth embankment with the outlet works located near the left end of the dam. An overflow spillway is located at a small dike approximately 800 feet to the left of the dam on a separate arm of the pond. The dam has a top width of 10 feet, a maximum height of 20 feet, a total length of 160 feet, an upstream slope of 3 horizontal to 1 vertical, and a downstream slope of 1.6 horizontal to 1 vertical. The outlet works consist of a 12-inch cast iron low level outlet or blowoff pipe controlled by an upstream gate. The overflow spillway consists of a concrete channel 5 feet wide by 5 feet high with slots for flashboards at the upstream end. The dam impounds Black Rock Pond, which is used for swimming and fishing. Based on the visual inspection, the dam is judged to be in poor condition. Features that could affect the future integrity of the dam are the downstream seepage, erosion of the crest and slopes, the presence of tree stumps on the slopes, and inadequate spillway capacity. The test flood inflow of 1,200 cfs results in a test flood routed outflow of 1,000 cfs that would overtop the dam and dike by 1.6 feet.

The Echo Lake Dam consists of an earth embankment with a maximum height of 18 feet, a top width of 12 feet and an overall length of 220 feet, including a 32 foot wide bituminous concrete auxiliary spillway located near the left abutment. The main spillway consists of a morning glory (drop inlet) type spillway located near the center of the dam. The outlet works consist of a 12-inch cast iron low level outlet or blowoff controlled by a manually operated gate valve located in the riser pipe of the morning glory type spillway. The dam impounds Echo Lake, which is used for swimming and fishing by residents of Watertown. Based on the visual inspection, the dam is judged to be in poor condition. Features that could affect the future integrity of the dam are continued erosion of the upstream and downstream slopes, seepage through the dam, and continued deterioration of the auxiliary spillway. The Test Flood inflow is 615 cfs and the Test Flood routed outflow is 510 cfs, overtopping the dam by 0.1 feet. The auxiliary spillway capacity with the water level at the top of the dam is 400 cfs and is equal to 78 percent of the Test Flood routed outflow. The capacity of the morning glory type spillway was neglected because of the potential for clogging.

The West Branch Dam consists of, from right to left, a 100 foot long earth embankment with an intake structure to a downstream canal, a 107 foot long concrete ogee section, and a 160 foot long earth embankment with a concrete core wall. The intake structure to the downstream canal contains two 42-inch sluice gates which discharge to the canal. The canal is separated from the river channel by an earth embankment which contains a 34 foot long auxilliary spillway. This spillway discharges into the river downstream of the dam. In the past, water from the canal would flow through a 36-inch reinforced concrete pipe (RCP) to a downstream manufacturing plant. The low level outlet, or blow-off, consists of a 48-inch RCP located to the left of the main spillway section and is controlled by a manually operated sluice gate. The dam has an overall length of 370 feet and a maximum height of 22 feet. The dam appears to be in fair condition and requires some work. The West Branch Dam has a tributary watershed of 33.3 square miles. The pond has a water surface area of 5.5 acres and a storage capacity with water level at the crest of the dam of 72 Acre-Feet. The main spillway has a capacity of about 8,200 cfs before overtopping the right portion of the dam.