摘要: Roberts Meadow Upper Reservior Dam is a cut stone masonry and earth gravity dam having a hydraulic height of 35 feet, length of 305 feet including a 150 foot long dike. The stone masonry section is approximately 65 feet wide, is s... 展开 Roberts Meadow Upper Reservior Dam is a cut stone masonry and earth gravity dam having a hydraulic height of 35 feet, length of 305 feet including a 150 foot long dike. The stone masonry section is approximately 65 feet wide, is slightly arched in an upstream ddirection, has a crest width of 4.5 feet and serves as the spillway. The 1/2 PMF test flood inflow for Roberts Meadow Upper Reservior Dam, having a drainage area of 8.8 square miles was determined to be 7480 cfs which would overtop the dam by about 3.4 ft. The spillway capacity at the top of the dam is 1500 cfs which is 20 percent of the test flood discharge. The dam itself is in poor condition. The major concerns are: The large amount of leakage through the stone masonry section which has the potential for freezing and dislocating stone blocks in the face of the dam; internal erosion of the earth embankment at the southerly end of the spillway; brush and tree growth on the embankment sections; and a large unstable mass of bedrock overhanging the downstream channel at the northerly abutment. 收起