DCR 999 Otis Reservoir Hydraulic and Mechanical Gate Systems Maintenance Service

This inspection and maintenance contract will have a contract term of five years for the purpose of performing annual maintenance on the hydraulic and mechanical gate systems at Otis Reservoir Dam.

The dam is an earthen embankment with a downstream stone masonry wall. The dam has a maximum structural height of about 31.5 ft and a length of about 630 ft. [...] The primary spillway, near the left abutment, was reconstructed as a 39-foot wide reinforced concrete primary spillway. Flows through the spillway are typically controlled with a 38-foot wide by 7.5 foot high hydraulic crest gate. The hydraulic crest gate was designed and fabricated by Rodney Hunt of Orange, Massachusetts. [...] The crest gate includes a heater system located within the side seals, along the invert hinge and at the lip of the gate.

Upstream of the crest gate, three 13-foot wide stoplog bays are present. Aluminum stoplogs are to be installed if the crest gate needs to be maintained or serviced. [...]

The outlet tower, which was constructed in 1984, has two; 48-in square slide gates on its downstream face which serve as a mid-level outlet at El. 1411 and a low level outlet at El. 1392.80. The slide gates are controlled with mechanical operators that were retrofitted with an electric motor inside the gatehouse. [...] In 2012, two, new stainless steel, 26"x25" slide gates, designed, and fabricated by Fontaine (i.e. Rodney Hunt), were installed on the upstream face of the outlet tower, where the 26-inch square, steel lined stone sluiceway connect to the tower. The new slide gates are controlled by electric operators, which also have the capability of being operated manually.