You may have noticed the Jan. 13 article in the Clinton item:
Lowering Dam Level May Be “Win-Win” Solution that outlines a preliminary proposal to lower the crest of Fyfeshire Dam. The Group for the Preservation of Fyfeshire Ponds met with members of the Bolton Conservation Commission to review the proposal, which is posted on the Bolton town website. (View proposal.) Here’s what we learned:
The dam as it stands now is almost 9 feet tall, bringing it within the jurisdiction of the state of Massachusetts, whose Office of Dam Safety has declared it structurally deficient and in an unsafe condition and ordered the town to complete a repair, breach or removal. The basic idea behind the new proposal, submitted by Fuss & O’Neill at the request of the town of Bolton, is to lower the top of the dam by about three feet—still above the water level under normal conditions, as illustrated below:
This would do a few things: First, it would make the dam safer in storm conditions without substantially increasing downstream flooding. The concern right now is that a large storm could raise the water level to the current height of the dam, putting pressure on it to the point where it could give way and release all the water in a rush, flooding the area downstream. If the dam were lowered, the pond might still overtop the dam in a large storm, but with the deficient structure removed, it’s much less likely to result in a catastrophic release of flood water.
Second, it would leave the big pond and general environment largely unchanged, since the water level does not reach the top of the dam. The smaller pond would be unaffected.
Third, it would make the dam “nonjurisdictional,” meaning that it would no longer be subject to the state’s dam safety regulations.
According to the report, this solution would cost between $159,000 and $243,000. Still not chump change, but much less expensive than earlier proposals for repair or removal which approached half a million dollars.
This solution is in keeping with the scale of the problem. Fyfeshire Dam is not, after all, in the same league as the Breeds Pond Outlet Dam in Lynn, a 50-foot dam that sits over a densely populated neighborhood of homes, schools and businesses. Most of the dams identified by the state as unsafe are at least 15 feet in height and impound 50 acre feet of water, according to a state report released a year ago. Fyfeshire, in contrast, is less than 9 feet tall and impounds a 10.3-acre pond.
There are still many details to be worked out, but we think the town is on the right track with this proposal. We will now shift our attention to raising funds to defray the costs to the town. Please support our efforts to keep Fyfeshire Conservation Area a beautiful recreation spot for all to enjoy. Your tax-deductible donations can be made to:
Friends of the Oxbow (on check, please write Fyfeshire on the memo line)
P.O. Box 646
Bolton, MA 01740