National Program For Inspection Of Non Federal Dams Merrimack Village Dam Nh 00115 Merrimack River Basin Merrimack New Hampshire Phase I Inspection Report

The concrete dam is about 180 ft. long and is constructed on a circular arc. It is small in size with a low hazard potential classification. The dam is in fair condition. At the present time, there is no way to draw down the level of the reservoir. A program of annual technical inspections of the dam should be undertaken.

The Souhegan River Watershed Dam No. 10A is located on Mill Brook approximately one mile upstream of Davisville, N.H. The dam is an earth embankment 951 feet long and 59 feet high with a drop inlet service spillway structure and a 30 inch outlet conduit. An earth emergency spillway 220 feet wide is cut into the left abutment. An earth emergency spillway 110 feet wide is cut into the right abutment. The dam is intermediate in size with a high hazard potential. The dam is in good condition at the present time. It is recommended that the owner retain the services of a registered professional engineer to investigate the cracking and erosion of the outlet conduit. Keywords include: Visual inspection, Dam safety, Merrimack River Basin, Wilton, New Hampshire, and Mill Brook, a Tributary of the Souhegan 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.

The Souhegan River Watershed Dam No. 13 consists of two earth embankment sections known as the main dam and the east dike. The main dam is 500 ft. long and 13.5 ft. high with a drop inlet service spillway structure and a 30 inch outlet conduit. The east dike is 620 ft. long and 9.5 ft. high with no outlet facilities. An earth emergency spillway 112 ft. wide is cut into the right abutment. It is small in size with a significant hazard potential. The dam is in good condition at the present time. No conditions were observed which require further investigation. There are various remedial measures which must be implemented by the owner. Keywords include: Visual inspection; Dam safety; Merrimack River Basin; New Ipswich, New Hampshire; and Unnamed tributary of the Souhegan River.

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 Souhegan River Watershed Dam No. 14 is located on Furnace Brook approximately 1/2 mile upstream of New Ipswich Center, NH. The dam is an earth embankment 1,500 feet long and 35 feet high with a drop inlet service spillway structure and a 30 inch outlet conduit. An earth emergency spillway 120 feet wide is cut into the left abutment. It is small in size with a high hazard potential. The test flood is the PMF. The dam is in good condition at the present time although there were some remedial measure which must be undertaken by the owner. No conditions were observed which require additional investigation. Keywords include: Visual inspection, Dam safety, Merrimack River Basin, New Ipswich, New Hampshire, and Furnace Brook tributary of Souhegan River.

The dam is about 720 ft. long and 35.5 ft. high. It is intermediate in size with a high hazard potential. In the event of failure of the dam, there is the potential of significant property damage and loss of life could result. The dam is in good condition at the present time. No conditions were observed which require additional investigation. There are a few remedial measures which should be implemented by the owner.

The dam is an earth embankment dam 695 ft. long and 69 ft. high. It is intermediate in size with a high hazard potential. The test flood for the dam is the PMF. The dam is in good condition at the present time. There are various remedial measures which should be implemented by the owner. The program of annual technical inspections should be continued. No conditions were observed which require further investigations.

Webster Dam is a concrete gravity structure with natural ground separating a concrete ogee spillway from a diversion canal near the right end of the dam. The total length of the dam is approximately 250 ft. with the spillway accounting for 154 ft. of the total length. The dam is small in size with a significant hazard potential. The test flood is between the 100 yr. and 1/2 the PMF. The dam is considered to be in fair condition at the present time. The wastegate and canal headwork structure are in very poor condition. Technical inspections should be scheduled every year. Keywords include: Visual inspection; Dam safety; Merrimack River Basin; Allenstown-Pembroke, New Hampshire; and Suncook River.

Sections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.