Connecticut River Basin, Manchester, Connecticut. Howard Reservoir Dam CT 00015. Phase I Inspection Report. National Dam Inspection Program.
CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV
Pagination or Media Count:
Howard Reservoir Dam is an earth embankment about 710 ft. long, with a maximum height of about 50 ft. and a crest width of about 15 ft. The spillway is located at the right abutment of the dam. It consists of a paved channel a 10 ft. wide ogee crested weir and training walls extending 3 ft. above the spillway crest to elevation 492 MSL. Above the top of the walls, the spillway opening becomes a modified V-notch with unpaved earthen side slopes rising to the top of dam, elevation 496 MSL, at 212 horizontal to 1 vertical. The gate tower, a wet well shaft, is located on the crest of the dam at its mid-span. It has 14 in. dia. and 20 in. dia. inlet pipes at elevations 469 MSL and 454 MSL, respectively. A 24 in. dia. blowoff pipe and a 14 in. dia. gravity flow pipe leading to Porter Reservoir provide the outlets from Howard Reservoir. Brush growth is becoming well established on the downstream slope. Minor seepage is evident at the downstream toe of the embankment about 300 ft. from the left abutment. There is a large rodent hole about 4 in. dia. and 3 ft. deep at the toe of the slope approximately 50 ft. to the left of the gatehouse. The dam is judged to be in generally good condition. The PMF test flood inflow of 2,600 cfs could overtop the dam by 0.7 ft., the total outflow being about 2,300 cfs. The spillway is adequate to pass on outflow corresponding to about 42 percent of the test flood outflow. The spillway discharge at top of dam, elevation 496.0 MSL, is 967 cfs.
- Civil Engineering