The town of Bristol, with assistance from engineering firm Wright-Pierce, will inspect and complete a structural analysis of the Bristol Mills Dam in early September.
The Bristol Mills Dam impounds the Pemaquid River below Biscay Pond and the greater Pemaquid chain of lakes. Bristol Board of Selectmen Chairman Chad Hanna said a comprehensive analysis of the structural integrity of the dam, which was last inspected in 1994, is part of an ongoing project to improve the fish ladder.
“We decided if we were going to invest the money on a new fish ladder, we didn’t want to find out the dam needed maintenance next year,” Hanna said. “We thought we would do it all as one project.”
An email sent out by Joe McLean, the project manager from Wright-Pierce, detailed a tentative schedule for the dam inspection. On or around Sept. 1, the stoplogs would be removed and the low-level gate would be opened to begin the drawdown of the water level. The drawdown is predicted to last a week depending on the flow of the river and rainfall.
“Our intent is to draw down the impoundment for the minimum time required,” McLean said in the email.
Wright-Pierce will also assess the approximately 30-foot-long spillway to determine the total water capacity and develop recommendations for improvements.
The estimated total cost of the assessment is $8,500.
Bristol Town Administrator Kris Poland said, in addition to finding out the state of the dam, the inspection will also allow Wright-Pierce to make suggestions to the town on how it can better manage the water level.
The board of selectmen plans to hold a public hearing before its meeting Wednesday, Sept. 2 to discuss the timing and the details of the drawdown as well as any possible effects it will have on the surrounding area.
“It may have some effect on the properties around Pemaquid River; it might not,” Poland said. “This time of year the water level is usually pretty low anyway.”
Hanna said the fire department has been informed of the drawdown so a proper contingency plan could be made if needed.
(Ed. note: This article has been updated from the Aug. 27 print edition to reflect a change in date for the public hearing to Wednesday, Sept. 2.)