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Sunday, March 16, 2014

Answering the question: Why is the Sebago Lake water table so low? - By Elizabeth Richards


The flow and depth of Sebago Lake is controlled by the Eel Weir Dam, which sits at the outlet of the lake and the head of the Presumpscot River. Sappi Fine Paper, which owns the dam, holds a license from the Federal Energy Regulation Commission to manage the dam in accordance with a Lake Level Management Plan that originated in 1997, was tweaked in 2000, and had major changes proposed in 2011 which have not yet been acted on. That proposal is currently under appeal.
 
Brad Goulet, hydro manager for Sappi Fine Paper, said that the current plan calls for lowering the lake early in the fall before the weather turns to freezing, with a goal of having the wave action scour the sandy shoreline and try to push it back up onto the beach. In the summer, he said, people want the lake to be full for recreational purposes. The boating and wave action can be counter to establishing a shoreline, and can in fact cause shoreline erosion as well as having a negative impact on water quality, he said.

Goulet said he doesn’t know what will happen with the current proposal, but that the changes were proposed by Sappi in large part to try and establish a plan that would allow for a more consistent outflow from the lake into the Presumpscot. “The main reason we proposed a change to the plan wasn’t so much for lake level as much as trying to establish a plan that didn’t require us to operate the river in what amounted to flood or drought conditions,” he said. 

There’s a big disconnect among people whose primary interests are in recreational or aesthetic aspects of Sebago Lake not realizing the impacts on the river, said Goulet. If the lake were kept full too long, the river would dry up and the lake water quality would deteriorate. The natural flushing of the lake is good for both the lake water quality, and the river, he said. 

In addition to the federal license mandates, said Goulet, the Eel Weir Dam also has a State issued water quality certificate under the Clean Water Act, which impacts what they are able to do.
There are many perspectives to consider when looking at lake level management, and it’s difficult to find a plan that will satisfy everyone. For example, said Goulet, the state park has the best shore frontage when the lake is around 2 feet below full, and at that same level, there are people who are upset, saying that the lake is empty. 

Goulet said it is improbable that they can continue to raise the level because in order to do so, you have to shortchange water going into the Presumpscot River. Sebago Lake accounts for 80 percent of the water flow in the river, and that has to support fish, waste treatment facilities from municipalities, kayaking, boating and fishing on the river as well.

The dam has been at the minimum flow of water, 17,500 cfm, for a month and a half, said Goulet, trying to get the lake level to come up. In the winter, it is difficult to get the water level up because the lake is frozen over, he added. They are also considerations around melting snow, and the potential for flooding. One of the proposed changes to the plan was to have a little more room for fluctuation in natural conditions. “When you’re trying to fill the lake in the spring, you really don’t know how much water is going to come at you from the snow pack. If you get a warm stretch and a bunch of rain, the opening in the river is only so big to get it out,” said Goulet.

The changes proposed do not call for differences in the top or bottom levels of the lake. Sappi would still try to fill the lake to capacity and lower the level in the same time frames, said Goulet. “It’s what happens in between that we looked for some latitude in, to try and level out what happens in the river,” he said.  

Goulet said he is happy to talk to anyone with questions. He also maintains a Tumblr blog where anyone who is interested can check in regularly, or subscribe to get email updates when something changes. Each week, he uses this blog to communicate what is happening in lake levels, and to inform the public on what Sappi is doing at the dam. The blog can be found at tumblr.com by searching for the words “Presumpscot River.”

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