This story by Aaron Calvin was first published by News & Citizen on June 12.
Just south of the popular summer destination of Lake Eden lies a quieter body of water.
South Pond, an idyllic retreat populated mostly by modest bungalow camps and accessible only to property owners, is, like many such bodies of water in the state, managed by a collective. The South Pond Land Owners Association charges a small annual fee for the maintenance of roads and property owned by the association, and the cost of insurance.
Among the shared assets is a small dam at the pond’s northwestern edge where it feeds into a tributary that eventually runs into the Gihon River. The 2-foot-thick concrete core is embedded within a sloping earthen wall, with only a concrete auxiliary spillway at the hill’s summit and a green box sitting just beyond it in the water as clues to its existence.
The century-old dam is a crucial one, however. Not only is it responsible for maintaining the water level in South Pond, but it also controls the flow of water out of the pond and into the lowlands. It was reclassified within the last few years from a “significant hazard dam” to a “high hazard dam” by the state, a designation indicating the outsized risk for loss of life and property should the dam fail. South Pond Dam is one of five dams with such a designation in Lamoille County.
This increased risk designation, though it has nothing to do with the condition of the dam — both the landowners association and the state attest to it being in excellent shape and at no risk of failure — and the increasing scrutiny of state regulators toward privately owned dams has pushed the South Pond community to take proactive measures to ensure the safety of their dam, which has meant a greater shared cost.
A routine inspection of the dam in 2022 concluded with the state recommending that the hydrologic and hydraulic analysis studies be conducted to evaluate the dam’s performance, including a detailed dam failure analysis, and act on the recommendations that come out of those studies.
After the issue was discussed by association members, the majority decided to begin conducting such studies despite the increased expense to its members.
“As one association member put it at our last annual meeting, we feel we have a moral obligation to follow up on the (dam safety program) inspection recommendations in order to minimize the risks to the people living downstream,” association officer Mark Frederick said.
A history of the South Pond dam
Even before the dam was built, South Pond had been a notable water formation in the county, albeit an inaccessible one, locked away in an Edenic wilderness considered remote even by Vermont standards, although the Lamoille Newsdealer noted in 1871 that was used by the local community as a reservoir.
In 1922, a St. Albans utility company constructed the dam, expanding the pond and turning it into a reserve for downstream hydroelectric facilities, or basically turning the pond into a big battery, as Ben Green, head of the state’s dam safety program, put it.
The dam failed in the flood of 1927, contributing to the most devastating deluge Vermont has experienced to date, according to Frederick. A dam inspector brought up from New York a year later declared it to be safe, but worth watching at times of heavy rain, according to a contemporaneous report in the News & Citizen.
In the intervening decades, campers marked out their territory along South Pond’s shores. The dam was acquired by the now-defunct Central Vermont Public Service. Property owners and the utility coexisted peacefully for years, until the owners petitioned the state to tighten regulations on the publicly accessible portions of South Pond in 1988.
This prompted the utility to claim it owned all the land within 15 feet of the shore. Though some landowners had deeds dating back decades, the records for the properties had “turned up missing,” according to the News & Citizen.
After a protracted legal battle, minutes from the South Pond Land Owners Association’s annual meeting in 1990 shows its members voted unanimously to acquire the rights to the pond — and its dam — for $98,500, paid off in installments.
‘Unintended consequences downstream’
For years, it was the responsibility of a designated neighbor to alter the flow of the dam during times of intense rainfall or in danger of flooding and to “exercise” the dam annually. Still, according to Frederick, the dam was “overbuilt” and water has never been close to rising to the height of the dam as it towers 15 feet above the pond’s usual water level.
This hand-operation method was replaced in 2004 by a spillway, a green box that sits in front of the dam and allows the free flow of water through it, allowing the pond to self-regulate. A primary concern of the state remains that the dam tunnel allowing water to pass through it has been unchanged since it was built, and there is no auxiliary spillway except at the top of the dam, where water can flow out and erode the ground encasing the dam.
A spot inspection conducted by the state following the July 2023 floods found the dam to be in good condition and in no danger of failure, though investigators recommended debris be removed from its spillway.
According to Green, who has worked closely with Frederick and the landowners association to address the concerns raised in the 2022 inspection, Vermont has lagged behind the rest of the country in regulating dams, and its authority to regulate privately owned dams has historically been weak, with the state unable to step in unless a failure is imminent.
That’s beginning to change, though efforts to phase in new regulations have been stymied by the distraction of multiple 2023 floods and another last summer requiring more immediate attention. Still, Green praised the South Pond landowners for being proactive and cooperating with the state of their own volition.
Frederick said the cumulative studies recommended by the state should cost between $100,000 and $150,000, a price tag that the association members were unable to afford to pay in a single year of collected dues. The state has allowed the association to pay for the undertaking study by study in annual installments, though this still means that landowners used to paying a few hundred dollars a year are now paying over $1,000 each year for the privilege of living on South Pond.
These studies could potentially lead to an eventual reconfiguration of the dam, Green said, which could in turn allow for the reduction of the dam’s hazard level and a higher condition rating.
The amount of water the dam pushes into the Gihon brings its own considerations. The dam’s spillway, particularly in extreme flooding events, simply releases the water gathering in South Pond into the Gihon, whose flooding contributed to the excessive damage that has reshaped the town of Johnson and other downstream villages. It’s the size of the passage below the dam, unchanged for over 100 years, that will be important to get right if any changes are made.
“Whenever you modify a spillway, you have to be careful in doing so. It might be attractive to release a bunch more water,” Green said. “While that sounds attractive, that can have unintended consequences downstream.”
South Pond is the model for the rest of privately owned dams in the state, Green said, but as the state increases its regulatory scrutiny, what are now recommendations being made by the state may become requirements.
“I think a lot of owners have gotten into a little bit of a groove of not really spending the money necessary, so this is going to be, unfortunately, a little bit shocking for some owners,” Green said.
