The Welchville Dam spillway on the Little Androscoggin River. Advertiser Democrat file photo

OXFORD — The Board of Selectmen held a workshop on Mar. 4 focused on options for maintaining Hogan and Whitney Ponds in the event that the Welchville dam fails or is removed.

Dave Cloutier, a hydraulic engineer with VHB Inc. of South Portland, presented findings of the water study he oversaw last fall with recommendations on how the town might proceed.

Cloutier said setting a series of controls in outlets of the two ponds would be feasible and could be set to maintain the current height of the dam. The controls, boulders placed as natural barriers to slow water flow, would behave like a dam at the outlet channels to keep water levels up.

With the Welchville dam in very poor condition, some type of change is needed. Its timber cribbing is rotting and stone cribbing is falling out. In 2016 Oxford considered plans for both dam replacement and repair, which then ranged from $0.9 million to $1.4 million.

Cloutier estimated that the cost for utilizing a natural grade control project would be about $44,000. It would include pre-permit consulting with Maine Department of Environmental Protection and the Army Corps of Engineers and work for site access, construction and clean-up.

Design for the system and any required additional engineering services would be additional expenses.

Steve Heinz of the Maine Council of Trout Unlimited spoke about the potential for grants to pay for the work. The Fish and Wildlife Foundation, NOAA Community Based Fisheries and the Maine Outdoor Heritage Fund are all organizations that provide funds for waterway restoration projects that restore connectivity for spawning fish. He said that grant requests that are coupled with removal of the dam will stand better chances for approval.

Select Vice-Chair Samantha Hewey said she is uncomfortable with any scenario that includes removing the dam. She pointed out that the grade controls offered no guarantee that the ponds would be preserved.

“If we replace or fix the dam it doesn’t make sense to do this project,” Hewey said. “Residents have made huge financial investments. We have a financial stake in that tax district. We’ve seen how low the water can get even in July. The water level could go still lower. There’s erosion, which we’ve gotten grant money to fix and have barely hit the tip. There are milfoil issues these guys have put in a lot of money and time in to fight. If the ponds become more shallow we make it warmer and easier for milfoil to grow.”

Cloutier responded that it will come down to the town’s decision. It can repair or replace the dam, or accept that the dam will go away and go with an option like natural grade controls. Controls ideally maintain pond levels where they are as if the dam is still there, at significantly lower cost than replacing the dam.

Another, more expensive option, could be to add a series of natural fishway with more pools and rapids to the shallow channels. But it still wouldn’t allow the kind of control Oxford is used to.

“With the dam you can open and close gates to set the levels,” Cloutier said. “With these [alternatives], you can’t do that, and water levels would go even higher after heavy rain.”

Cloutier gave several examples of other waterways in Maine where natural grade controls were installed to mimic the purpose of old dams.

Selectmen Sharon Jackson pointed out that the $44,000 estimate did not include designing the project. She said before a final decision can be made the Board will need more information on the options available, including pros and cons to each. She also wanted a more complete cost estimate from VHB, Inc. for expenses beyond the $44,000. Hewey added that it was important to include a financial impact review on property values and tax revenue.

One resident raised the point that many of the waterfront homes are owned by people who do not have children in the school system and are located on private roads that are not maintained by public works, providing the town with tax revenue that doesn’t include a high demand for services.

Hewey also said she wanted the opportunity to do site visits to ponds in other municipalities to see how the grade controls worked, and also talk with landowners and local officials about impacts they have experienced switching from dam to natural controls. Cloutier said he would be able to provide selectmen with that information.