South Pond Dam is an earthen embankment dam with a vertical stone masonry wall downstream face. The embankment is approximately 300 feet long and has a maximum height of 19 feet. The dam has two spillways. The visual inspection of South Pond Dam indicated that the dam is in fair condition. The inspection revealed that lack of adequate riprap of the upstream face has caused erosion at the splash zone of the embankment. Tree stumps exist in the downstream slope of the embankment along the right training wall and buttress wall of the center spillway. Bulges up to 3 feet offset were located in 3 areas of the vertical stone wall on the downstream face of the dam. Water with staining was observed along the downstream toe along the right side of the embankment. Erosion was found adjacent to the emergency spillway on the left abutment. Brush, trees and debris are located in the downstream channel of the left spillway. Animal burrows were found in the embankment. The spillway will pass 590 cfs or 16% of the test flood with the pool level at the top of the dam. The test flood flow of 3900 cfs will overtop the dam by 2.1 feet.

Parks Pond Dam is a cyclopean masonry/earth embankment that is approximately 180 feet long and 12 feet high. The earth embankment is on the downstream side and has a 2:1 slope. The upstream face is cyclopean masonry with a vertical face. The spillway is located on the southern half of the dam and consists of a 30.5 foot long weir. There is a lower gate house for the control of a discharge pipe that passes through the base of the dam. The size of the pipe is unknown. The valve for the operation of the discharge pipe is inoperable. The drainage area is 0.5 square miles and the reservoir has 100 acre-feet of available storage. The assessment of the dam is based on the visual inspection, past operational performance and hydraulic/hydrologic computations. The dam is judged to be in poor condition with several areas that require attention. These areas include seepage through the dam and around the spillway's west training wall, deteriorated concrete of the spillway and upstream face of the dam, vegetation on the embankments and along the toe of the dam and the nonoperating status of the blowoff. The dam is classified as small and has a significant hazard potential in accordance with guidelines established by the Corps of Engineers. The test flood for this dam is 1/2 the Probable Maximum Flood (PMF). The test flood inflow is 625 cfs and the routed test flood outflow is 473 cfs. The test flood outflow will overtop the dam by 0.55 feet.

The maximum height of the dam is 27 feet at the left edge of the spillway. The reservoir storage at the top of dam is 11 acre-feet. There are both upstream and downstream spillway training walls composed of mortared and hand placed cobbles respectively. The visual inspection of Risdon Pond Dam indicated that the dam is in fair condition. The inspection revealed that the unprotected upstream face has been slightly eroded by wave action. The downstream face of the dam has a number of blocks which have been displaced, cracked or have unmortared joints, Grass, moss and small trees are growing out of some of the joints. There are several areas of seepage along the downstream wall both sides of the spillway. There is a 3-foot deep depression on the left downstream wall of the dam. Also, there are five large tree stumps along the crest of the dam and a footpath traverses the crest. The spillway will discharge 220 cfs, or 16% of the test flood with the pool level at the top of the dam. The test flood flow of 1420 cfs will overtop the dam by 2.0 feet.

Twin Lakes Dam is a 20 foot high earthen embankment and the length appears to be approximately 100 feet. The dam is in good condition. The inspection revealed cracks parallel to the dam crest in the pavement and dipping of the road surface in the areas of the intake structure. Brush and trees occupy the upstream face of the embankment left of the structure. The upstreams face right of the sructure is a maintained lawn with tress. Trees are also found on the downstream face. Soil erosion and a wet area were observed on the downstream face of the embankment. Loose blocks of stone were found in the right downstream channel. There is no spillway at the dam. The outlet works consists of 1-24 inch diameter and 1-36 inch diameter pipe whose maximum possible discharge is 225 cfs. This capacity is considered insignificant in terms of consideration of the outlet works as a storm attenuating discharge facility. However, at the top of the dam elevation of 736 feet there is available surcharge storage of 3600 acre-feet which is equal to the test flood volume of 3610 acre-feet. Therefore, the test flood volume of 1/2 PMF will be contained without overtopping the dam and without releasing any of the storm inflow downstream.

The dam consists of an embankment at the south end of the pond and two dikes at the northeast end of the pond. The approximately 19.5 foot high dam on Hart Brook is an earth embankment approximately 325 feet in length including, at the left end of the dam, a 37 foot long rounded, broad-crested concrete spillway founded on rock. The two dikes along the northeast edge of the reservoir are referred to in this report as the North Dike and the South Dike. The dikes are about 8 feet and 15 feet high respectively, on the downstream side. The shape of the dikes is very irregular; the crest elevation is not constant, and is, on the average, four feet lower than the crest of the dam. Based upon the visual inspections, the dam appears to be in good condition while the dikes appear to be in poor condition. No evidence of instability was observed in the dam or dikes, however, the height of the dikes is inadequate; the dikes have an irregular configuration and excessively steep slopes; there is extensive tree and brush growth on the dikes and seepage through the dikes and dam. The spillway capacity to the point of overflow of the dikes is 120 cfs which is equivalent to 10% of the routed test flood outflow.