OXFORD — The Board of Selectmen have OK’d an $8,900 contract with MBP Consulting of Portland to design a new gate for the east sluice at Thompson Lake Dam.
The action, taken at the board’s November 15 meeting will, in part, allow Myron B. Petrovsky of MBP Consulting of Portland to design the gate concrete works and prepare engineering sketches of the concrete work. The report, which will be presented to the selectmen, will include the estimated construction costs.
In September, a diving company spent three days at the dam completing major repair work on the centuries-old dam that controls the level of lake water. Concern arose last summer when leaks were detected around the east sluice of the dam and water was found seeping into the Robinson Mill on King Street intake tank that went from the dam to the underside of the mill. The problem posed a threat to the mill, said officials.
The dam is owned by the Town of Oxford but benefit’s the lake water on which residents from Oxford, Poland, Otisfield and Casco live and recreate.
An advisory committee, chaired by Town Manager Butch Asselin and made up of two members of Casco, Otisfield, Poland and Oxford, has been reviewing the the condition of the dam and determining present and future needs.
A dam review by MBP Consulting this summer determined that the dam’s operational east gate was releasing water too quickly because the dam gates were bowing significantly. Emergency repairs were made including plugging of leaks, replacement of corroded anchor bolts on the gate guides, placing cement around the gate guides and reinforcing the east sluice with additional hemlock planking.
Some water continued to get through the gate but the dam was deemed safe at that time.
According to a proposal from MBP Consulting, the new gate would replace the existing “inefficient and unstable” stoplog system and increase hydraulic capacity and operation flexibility of the dam.
The flow is currently controlled in the east sluice by a system of stoplogs that are protected by a steel bulkhead installed upstream of the stoplogs,
According to the proposal, ” new stoplog guides would be designed if necessary and a the gate concrete works would include overlying the sluice floor and walls with reinforced concrete to protect the existing masonry from erosion and control masonry leak.”
Construction costs will be presented to the the town or the Thompson Lake Dam Committee.