National Program for Inspection of Non-Federal Dams. Weymouth River Basin, Braintree & Randolph, Massachusetts, Great Pond Upper Reservoir Dam MA 00823. Phase I Inspection Report.
CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV
Pagination or Media Count:
Great Pond Upper Reservoir Dam consists of three homogeneous earth embankments the left embankment known as Dike A is about 132 ft. long and 14 ft. high the middle embankment known as Dam B is about 1,264 ft. long and 18 ft. high and the right embankment known as Dike C is about 877 ft. long and 12 ft. high A concrete ogee-shaped spillway and stoplogs structure is located about 110 ft. left of the right abutment of Dike C. The spillway discharges into a paved stone masonry channel that leads into Great Pond Lower Reservoir. A valve chamber located in Dam B houses four valves which control the low level flows from the upper reservoir to the lower reservoir. The routed test flood outflow of 4,380 cfs overtops the crest of the embankments by about 0.8 ft. The spillway with stoplogs in place can pass 330 cfs or about 7 percent of the routed test flood outflow without overtopping the embankments. The dam and appurtenant works are judged to be in generally good physical condition, however, the overall condition of the dam is only fair owing to the inadequacy of the spillway. Light brush was growing on the upstream slopes of all embankments and a light growth of trees and dense brush and small trees were prevalent on the downstream slopes of all embankments. There was also a light vegetative growth through the floor of the wasteway. The crests of the embankments have been rutted by vehicular traffic. The valve chambers concrete is in need of repair and, though the valves within the chamber were not inspected, they were reported to be operative.
- Hydrology, Limnology and Potamology
- Civil Engineering