National Program For Inspection Of Non Federal Dams Goffs Falls Dam Nh 00292 Nhwrb 15005 Merrimack River Basin Manchester New Hampshire Phase I Inspection Report

The dam is a gravity structure constructed of split masonry. It is about 80 ft. long and 17 ft. high. The dam is small in size with a significant hazard potential. The dam is in poor condition at the present time. There are remedial measures and studies which should be implemented by the owner as soon as possible. (Author).

Kelleys Falls Dam is a run of the river type dam, with an overall length of 503 feet. Visual inspection of the dam indicated that the dam is in poor condition. The inspection revealed a number of leaks through the mass concrete spillway section, considerable loss of concrete from the spillway section, seepage around the concrete wall on the right side of the dam, and general deterioration of concrete on the abutments and hydro-building. Based on the intermediate size of the dam and the significant hazard classification and in accordance with Corps of Engineers guidelines, the test flood is one half the Probable Maximum Flood (PMF) or 55,900 cfs. The one half PMF outflow overtops the dam by 6.8 feet. With the water level at the top of the dam, the spillway will pass 38 percent of the test flood outflow. It is recommended that the owner engage a qualified engineer to make thorough investigation of the condition of the foundation of the spillway section of the dam, investigate the structural stability of the spillway section and ways to increase the spillway capacity. Also, the owner should remove the flashboards on the dam immediately. Additional keywords: Merrimack River Basin, Manchester, and New Hampshire.

The Souhegan River Watershed Dam No. 26 is located on Blood Brook, a tributary of the Souhegan River, approximately 2 miles upstream of West Wilton, New Hampshire. The dam is an earth embankment 692 feet long and 79 feet high with a drop inlet service spillway structure and a 30 inch outlet conduit. An emergency spillway 320 feet wide is cut into the left abutment.

The dam is a stone masonry gravity dam with a total length of about 325 ft. It is small in size with a low hazard potential. The dam is in fair condition at the present time. In light of the dam's fair condition, technical inspections should be made every year. (Author).

The dam is a 188 ft. long, 16 ft. high earth embankment dam. The condition is fair. The visual inspection did not disclose any immediate safety problems. The dam's spillway will not pass the test flood, therefore it is recommended that the owner engage a qualified engineer to evaluate further the potential for overtopping the inadequacy of the spillway. (Author).

The dam is a concrete lined earth and rock fill embankment that is used as a water supply. The dam has a maximum height of 35 ft. It is small in size with a high hazard potential. In the event of a failure, several downhill residences would be threatened. The reservoir is in good condition. No displacement settlement, or other signs of major distress were observed at the reservoir. (Author).

The dam is an earthen embankment structure with a central concrete core wall about 147 ft. in overall length and 9 ft. high from the crest of the dam to downstream toe. The dam is considered to be in fair condition. It is classified as small in size and significant in its hazard classification. (Author).

Chase Pond Dam is a rock filled log crib with timber planking overflow structure between stone and concrete embankments. The overall length of the dam is 103 ft. The timber overflow section is approximately 12 ft. high by 50.5 ft. long and 10 ft. wide at the crest. The embankments, which are approximately 5.4 feet higher than the crest of the timber overflow section, are composed of masonry and concrete on the upstream and training wall faces. As a result of the visual inspection of this facility, the dam is considered to be in poor condition. The dam is small in size with a significant hazard classification. The dam at the outlet from Tannery Pond could be overtopped or breached. Keywords include: Inspection, Dam safety, Merrimack River Basin, Wilmot, New Hampshire, and Chase Pond.

St. Pauls School Dam is a concrete overflow section approximately 15 ft. high from the bottom of the upstream channel to the top of the training walls and approximately 100 ft. long between the training walls. The upstream face of the concrete section is vertical and measures approximately 9 ft. from its crest to a concrete apron on the channel bottom. The dam is in fair condition at the present ime, with a few major concerns which must be corrected. The size is intermediate with a significant hazard potential. The dam could be damaged by the discharge over the abutments. It is not anticipated that lives would be lost. Keywords include: Visual inspection, Dam safety, Merrimack River Basin, Concord New Hampshire, and Turkey River.

Mountain Pond Dam is located on the north end of Mountain Pond in Sanbornton, N.H., in mountainous terrain two miles south of the village of New Hampton. The dam is an earth embankment, 97 feet long and 14 feet high with a gated 8-inch outlet. The impoundment stores the water supply for the Town of New Hampton and is also the fire protection reserve. It is small in size with a low hazard potential. The test flood is in the range of a 50 to 100 year frequency. The condition of the dam is considered to be fair, requiring that modifications be made by the owner within 1-2 years after receipt of this inspection report. Keywords include: Inspection, Dam safety, Merrimack River Basin, Sanbornton, New Hampshire, and Tributary of Pemigewasset River.