LEEDS – This spring, thanks to new flashboards on the Dead River Dam, the floodwaters of Androscoggin River have been held back from entering Androscoggin Lake, which many people say looks cleaner this summer.

“For the first time in several years, no polluted Androscoggin River water flowed into Androscoggin Lake,” said Molly Saunders, volunteer for the Androscoggin Lake Improvement Committee. “Many people say the lake looks cleaner,” she added. “It really is much clearer this summer.”

The Dead River, which serves as the outflow to Androscoggin Lake, meanders through Leeds and North Leeds until it joins with the Androscoggin River. Most of the time, the water flows away from the lake, but during floods, the Dead River reverses course as the Androscoggin River swells.

The ALIC has complained for years that the dam, about halfway up the Dead River, has been ineffective in keeping floodwaters out of the lake. Nearly every spring the dam has overflowed, allowing phosphorus and paper mill wastewater from the Class C Androscoggin River to enter the lake. Algae blooms on the lake, a popular bass fishery, are a continuing worry, Saunders said.

The flashboard project has funding through a $40,000 emergency appropriation approved by the state Legislature. The Maine Department of Environmental Protection contracted last December with E/PRO of Augusta to do the work.

The flashboards are supported by sturdy vertical metal pins placed close enough together to withstand the heavy logs that butt up against the dam during flooding, according to Andy Straz of E/PRO, who did the hydrology study.

The boards are 3 and 3 feet high, and the top of the concrete at the dam is 275.3 feet, so the dam is now holding out reverse flow floods up to 278.3 and 278.8 feet, which is about the height of a two-year flood, Saunders said.

“So the good news is that the dam is now high enough to hold out the smaller floods, which happen on average about two to three times a year,” she said. This spring there was one flood which came right up to the top of the flashboards on the riverside. The water stayed that high for three days, but did not go over the boards. Improvements were also made to riprap on one side of the dam, and trash rack grates were installed on the lake side.

The state Department of Agriculture officially owns the dam but hasn’t maintained it for years. The ALIC, at its own expense, installed 2-foot flashboards, but they were ineffective.

“We hope that if we can stop these chronic yearly floods, the phosphorus levels will go down,” Saunders said. But it’s not clear that the flashboards represent a permanent solution.

“The whole ecosystem has to be monitored,” she said. The lake may come back from the edge of having an algae bloom every year if there is no flooding for the next five years, she said. But the flooding supported the lake’s delta. “Will the delta shrink if the flooding stops? We don’t know the answer to that,” she said.

There’s also a concern about the impact that a lack of flooding will have on rare plants that grow in the Dead River delta, Saunders said.

The flashboards on the Dead River dam may also play a part in the DEP’s upcoming recommendations on how to maintain minimum dissolved oxygen water quality standards for Gulf Island Pond, the dammed-up portion of the Androscoggin River south of Androscoggin Lake.

The DEP is meeting this summer and fall with a group of stakeholders called the Gulf Island Pond Working Group and is expected to decide the issue by December. Saunders said Androscoggin Lake will be impacted by whatever decision is reached.

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