Boundary Pond Dam Breached
by Claire Lynch
Colebrook News and Sentinel
June 3, 2010
The dam at Boundary Pond in Pittsburg is being breached this week for reasons of public safety, according to an engineer from the Dam Bureau of the N.H. Department of Environmental Services. East Inlet Road at Mile Marker 3 is closed until the danger has passed, and anglers and paddlers are encouraged to seek alternative waters.
The future of this dam is unclear, said a representative from The Forestland Group of Chapel Hill, N.C., which owns the Connecticut Lakes Head-waters property where Boundary Pond is situated. This dam, along with others on the property, will be discussed at the next Headwaters Committee meeting to be held at the Pittsburg Fire Station on Saturday, June 26, beginning at 10 a.m.
Boundary Pond, also known as Mountain Lake, is a 33-acre body of water held back by a timber crib dam built by N.H. Fish and Game in 1953. "Fish and Game bulldozed over a previous dam and added this new wooden spillway," explained chief engineer James Gallagher Jr. Some repairsū˙were made following a dam failure in 1985, but all in all, the structure has far outlived its 25-year expectation.
During an annual inspection of all North Country dams last week, Mr. Gallagher discovered a recent failure of the left earthen embankment of the Boundary Pond dam, next to the training wall of the timber spillway. "I was shocked at what I saw and what had clearly happened," he said. "Over the winter a slope failure created a huge sinkhole."
He said water got in behind the crib and deteriorated the timber bar. Some pieces of timber have floated downstream, he said. Mr. Gallagher determined that the dam is no longer structurally stable, and he believed a complete failure was imminent.
If the dam were to fail, he said, it would release a large amount of water down a steep grade through at least two ponds formed by beaver dams. The resulting flood would likely wash out the East Inlet Road at the culvert at Mile 12, and endanger anyone immediately downstream.
To remove this threat, the DES Dam Bureau has directed that about 25 feet of the dam be dismantled in order to control the release of impounded water. The dam does not have a low-level outlet to lower the impoundment, according to a press release from Fish & Game.
Boundary Pond is a valued fishery due to its high elevation and cool waters, Mr. Gallagher noted, but a replacement dam will not be built unless it is approved by the state legislature and The Forestland Group. A new dam will also have to meet modern specifications, he said.
The dam has not been maintained regularly since 2004, he said, when a maintenance lease with Fish & Game expired. Consequently the Forestland Group, which purchased The Connecticut Lakes Headwaters property last year, bore the sole responsibility.
"The issues surrounding dam ownership and maintenance and the associated liability concerns are complicated," read an e-mail statement from John Steward, regional forester for LandVest Timberland, the company charged with managing the forest.
According to Northeast regional director Matt Sampson, TFG has not yet decided on the future of the dam. The company was caught off guard by the inspection results, he said; "We are uncertain as to the number of dams affected." He explained that the dams vary in size and construction and include those that were made by beavers.
The company is open to discussion of the pond's future, he said, but noted a "myriad of complexities" including how many ponds the company has contract ownership and their conditions. Public access and safety must also be taken into account in each case, he said.