The aging dam that is supposed to control the water level in Maranacook Lake soon could be undergoing some improvements.

The dam is at the outlet of Maranacook Lake, near the Winthrop Town Beach.

But the lake stretches from Winthrop to Readfield, and taxpayers in both towns would cover the bill for repairs and renovations.

As both towns begin preparing next year’s municipal budgets, a special committee that includes Readfield and Winthrop residents soon will seek bids for a construction project that has been in the works since 2013 and will cost an estimated $237,000.

It calls for repairing parts of the dam that have deteriorated and improving its ability to release lake water quickly into the outlet stream.

Both towns already have raised some of the money for the work, and the dam committee is asking them to raise the remainder in the 2017-2018 fiscal year.

Based on the lake frontage is in each town – 10.2 miles in Winthrop, 11.6 miles in Readfield – Winthrop would pay for about 47 percent of the proposed work and Readfield would pay the rest, according to Wendy Dennis, chairwoman of the dam committee and a lake scientist with the Cobbossee Watershed District.

In 2006, Winthrop and Readfield became co-owners of the dam whose former owner, Carleton Woolen Mills, had gone bankrupt a few years earlier, Dennis said.

The current dam was built in 1995, but it has deteriorated in the last 20 years and can’t release water fast enough to keep the shoreline from flooding, Dennis said.

In the spring, Dennis said, lake levels can rise up to 2 feet, sending water onto lawns, causing erosion and damaging docks and other property.

The current dam lets water out through a gate that’s 5 feet wide, according to Dennis. The proposed modification would expand it to 20 feet.

The new gate also would be deeper than the current one, making it easier for the dam’s operators – currently the Winthrop Public Works Department – to release water ahead of rainstorms or spring melting.

While those improvements would not stop flooding, Dennis said, they would reduce the number of days it takes lake levels to return to normal after a storm.

According to hydrological modeling, a rainstorm that now would raise the lake level more than a foot and take two weeks to dissipate would, with the improvements, raise levels less than a foot and take about five days to dissipate, Dennis said.

“In between storms, it will also allow us to adjust lake levels to whatever is beneficial for that time of year,” Dennis said.

“For summer, we could make it high enough for boating but not high enough that the waves create erosion. Some residents want more beachfront, but right now we can’t alter levels to reach those objectives.”

The project also would stabilize the dam by replacing concrete that has deteriorated, Dennis said.

Tom Heiss, whose Winthrop home overlooks the dam, said he and his neighbors have experienced flooding and he has lost several feet of property to erosion.

Heiss, who also sits on the dam committee, said one reason for area residents to support the repair now is to reduce the risk of a serious breach later.

“I didn’t want to see what’s happened in California happen here,” he said, referring to a recent scare in which 200,000 people were ordered to leave their homes in Oroville, California, after a hole was spotted in the spillway of a mammoth dam there, threatening homes below.

The dam on Maranacook Lake wouldn’t pose so serious a risk, but Dennis also said the costs to repair it will only grow over time.

The dam committee probably will seek bids for the work in early March, Dennis said.

If Readfield and Winthrop raise the remaining money for the dam project this spring, she said, construction could begin as soon as July and take three to four months.

Charles Eichacker can be contacted at 621-5642 or at:

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Twitter: @ceichacker