Decades of inspection reports outline Helderberg Lake Dam’s fall from compliance

Enterprise file photo — Noah Zweifel

The wall of the Helderberg Lake Dam, with the spillway barely visible.

BERNE — During the half-year of public meetings dedicated to the subject of how to fund repairs for the Helderberg Lake Dam, in Berne, the Helderberg Lake Community Association has faced a tough line of questioning from town officials and unhappy residents about when problems were made known and what should have been done. 

Decades of inspection reports received by The Enterprise from the New York State Department of Conservation this week show that, while there were indeed problems with the dam, both physical and administrative in nature, it was ultimately in compliance with state regulations until six years ago.

The reports also show that the town has been in the loop all along, as the Berne supervisor has been receiving these biennial reports since at least 2010. 

In 2016, the first year that reports indicate that the high-hazard dam had an “unsound” designation, an inspector noted that the dam had seepage, cracking, movement/misalignment, surficial deterioration, and problems with maintenance. 

But its designation appears to have been derived from the fact that the Helderberg Lake Community Association had not submitted an engineering assessment that had been due in 2014, despite an extension request that year. 

The association could not immediately be reached for comment about the late submission. 

That 2016 designation (“unsound — more information needed”) is different from the one it currently has (“unsound — fair”), which was applied in 2018, a DEC official told The Enterprise last month, and which is confirmed by the 2018 inspection report. 

The 2018 report shows that the lake association had submitted all necessary paperwork (except for an annual certification) but that the most recently submitted engineering assessment — which the report says was “last updated” early that year — determined that there were issues with the dam. 

The report does not outline what those issues are, but the current repair plans are to “add stone to the downstream embankment to improve the dam’s stability, raise the dam crest and core wall by one foot to prevent overtopping during the ½ of the probable maximum flood storm event, some concrete repairs to the existing core wall and spillway, and potentially [add] a siphon system for lowering the impoundment during an emergency situation,” the DEC told The Enterprise. 

While the concrete repairs and other issues appear to have been necessary in some form or another since at least 1970, according to the reports (with at least one noting evidence of repairs), the matter of raising the dam to prevent overtopping “during the ½ of the probable maximum flood storm event” is relatively recent, and relates not to any deterioration in the dam but different sourcing by the state to determine the ½ probable maximum flood value. 

The 2008 inspection report notes that, although the spillway capacity had been determined in 1980 to be sufficient, the source of flood estimates used at the time, Hydrometeorological Report 33, published by the United States Army Corps of Engineers, had been superseded by new regulations, estimating “higher design flow rates, and as such may indicate that this dam has inadequate spillway capacity.

“This potential deficiency should be evaluated as part of the full engineering assessment of the dam, as will likely be required by the proposed draft regulations,” the report reads. 

The 2012 report states that the “first engineering assessment of a small, Class C dam is due no later than August 19, 2014,” which was exactly five years after the state officially updated its dam regulations. The report notes that assessments are due every 10 years thereafter. 

Prior to the updated regulations, the inspection reports give no indication that there are any serious problems with the dam, instead summarily noting various deficiencies. None of the reports offers any overall impression of the dam’s condition, except for the 1984 report, which lists the dam in “fair to good condition” despite cracks, spalling, movement, and seepage. 

The Helderberg Lake Community Association is currently requesting that the town take out a $500,000 loan to fund the repairs, which would be repaid by the residents of Helderberg Lake, the majority of whom have signed a petition showing their support for what would be a newly-formed tax district. 

The town board, however, has appeared resistant to the idea following a series of meetings in which opponents of the district have shown up in force to criticize the proposal and denigrate the lake association for its supposed mismanagement of the dam.

The DEC told The Enterprise last month that, if the dam is not brought up to standard, “it could lead to DEC issuing an Order to have the dam repaired or removed in order to gain compliance with Dam Safety regulations.”  

Removal of the dam would turn the manmade lake into wetlands and would cost $424,000, engineers from Prime AE Group, the engineering firm contracted by lake association, told the town board last year.

In the event that the dam fails, its designation as a high-hazard dam suggests that loss of life or widespread economic damage is likely, according to state law. 

Tags:

More Hilltowns News

  • The 37-acre, 5-megawatt solar project proposed by RIC Energy received conditional approval from the Knox Planning Board last month as the town board works to negotiate a payment-in-lieu-of-taxes agreement among the company, the county, and the Berne-Knox-Westerlo School District.

  • Berne-Knox-Westerlo voters re-elected incumbent, unchallenged school board candidates Matthew Tedeschi and Rebecca Miller; approved the district’s $25 million budget; and authorized the purchase of several buses, as well as a property that sits adjacent to campus. 

  • The farmers’ market, which features a wide variety of vendors from the Hilltowns and beyond, will continue to be held each Wednesday through most of October from 4 until 7 p.m. at the Helderberg Lutheran Church, in Berne. 

The Altamont Enterprise is focused on hyper-local, high-quality journalism. We produce free election guides, curate readers' opinion pieces, and engage with important local issues. Subscriptions open full access to our work and make it possible.