BURRILLVILLE – A historic, century-old dam will likely need additional work – even after the current $1.8 million maintenance project is complete – according to Public Works Director Jeffrey McCormick.
Consultants recently told McCormick that five times more water should flow through the Harrisville Dam, a standard town officials noted would be impossible with the current design.
“This is going to be an interesting problem for this town over the next few years,” McCormick told Town Councilors at a meeting on Wednesday, Feb. 10.
The 140-foot-long dam, built in 1857 at a cost of $6,000, drew the attention of officials last year, when leaking and growing sink holes became a major cause for concern. Councilors approved a $1.8 million project last June to finance dam work with the help of a loan from the Rhode Island Infrastructure Bank.
This week, McCormick told councilors that the sink hole problem has been resolved.
“That’s been stopped, so there’s no imminent danger at the dam,” he said.
Upcoming approved work includes replacement of loose stones in the wall and riprap on the east side, and replacement of a low level orifice, a construction project McCormick said will likely begin in the summer of 2022.
But consultants recently performed a hydraulic study, and reportedly told the public works director that new regulations from the Rhode Island Department of Environmental Management require around five times as much water to flow through the structure.
“This does not affect our current project,” McCormick said. “They’re saying we need to get five times more water through the dam.”
“That’s not possible,” responded Councilor Dennis Anderson.
“I know,” McCormick said.
Currently, a stone arch and pedestrian bridge run over the area, leaving just a few feet of space for more water.
“Until that bridge is changed you’re not going to get that much water through,” noted Councilor Jeremy Trinque.
McCormick said the next step is to order an inundation study to see how five times more water would affect the area. The solution, he noted will likely involve getting more water through the wall via an underground culvert with additional sluice scapes and stop logs, without ruining the aesthetics.
“We have the potential for a nice little area there for the residents of the town,” McCormick said.
The changes won’t equate to five times the water flow, but McCormick noted that the town will be closer to the standard, and can work with RI DEM.
“If we know that we have to do something in the future we can design these things so that they can be incorporated into some kind of other crazy output construction,” McCormick said. “At least we know that something may be coming down the road.”
