Exeter River Study Committee Provides Facts and Information
The Exeter River Study Committee provides facts and information, based on thoughtful and thorough engineering and environmental science, regarding the potential approaches to address the currently unsafe condition of the dam. For the past 100+ public meetings the Committee has been extremely careful to ensure a full consideration of all possible solutions and to not advocate one alternative over another. Its goal has been to ensure that the public decision making process is based on an objective view of the situation.
In this regard, I do not want my response to be seen as a rebuttal of Selectman Quandt's opinion that dam removal is "the worst option." However, Selectman Quandt's letter raises profound questions that could leave the reader believing that certain issues have not been fully examined. So, in that spirit, I would like to provide some information that may help the reader fully understand the issues raised in Selectman Quandt's letter. Where appropriate, I have included aspects of the responses by Selectmen Clement and Ferraro.
1. Selectman Quandt: "I believe tearing down the dam will put our water supply at risk. In the summer, the Exeter River is one of our primary sources of drinking water."
Selectman Ferraro's response: Regarding the town's water supply, the River Study Committee's report concluded that, even in extreme drought conditions, the town will have drinking water. The number one recommendation was the installation of the groundwater treatment plant, a step that is already underway as it will reduce operating costs. Further, the DPW has stated at a number of meetings that the new plant will be online before we actually remove the dam so there is no jeopardy to our water supply.
I would add: The need for diversifying the Town's water supply is independent of the dam removal: most of the actions related to water supply recommended in the committee's report are advisable whether the dam is removed or not. However, dam removal would have a slight adverse effect on the yield of the Gilman and Stadium wells - about 11% reduction in a maximum safe yield. Our conclusion is this loss would not have a significant adverse effect. Moreover, a simple retrofit to the Town's river intake would help to ensure that the river intake would continue to function even under low flow conditions.
2. Quandt: Secondly, “we do not have a concrete answer as to how lowering the river will affect our natural animal habitat and our wetlands in the river.”
Selectman Ferraro's response: Regarding wetlands, the report devotes a chapter to Natural Resources. It does acknowledge the existence of a swamp oak forest that will decrease in size with dam removal. The report concludes, "In summary, it is expected that the overall effects of this alternative [dam removal] on wildlife would be minor and would be offset by the benefits of restoring upstream migration to anadromous fish species."
I would add: Additionally, the report concludes that the dam removal would have a significant net ecological benefit.
3. Selectman Quandt: "Thirdly, we have not discussed any of these issues with our neighbors, Kensington, or South Hampton or any other towns that could be harmed by us lowering the river."
The complex and comprehensive set of models of the river, which are capable of predicting, with a fairly high degree of certainty, show that the potential effects on Kensington would be negligible. There may be some effect on shallow wells, which do not draw on the deep bedrock aquifer. The primary potential effect could be ecological, with some plant community shifts in certain wetlands which cross into Kensington. But, as explained in the technical report, these changes would occur over a period of decades, would be very difficult to measure, and likely unnoticeable to anyone. The Town asked the Town of Kensington if they wanted to be involved in the study; there was no reply. While South Hampton is not in the watershed, a small portion of Hampton is within the watershed. The impacts on this portion of the watershed are essentially zero and thus were not mentioned in the report.
Frank Patterson, Exeter
Member –Exeter River Study Committee
(Editor’s Note: This letter is the first of a two-part series to address the concerns raised at a recent meeting.)