Contributed Photo FEDERAL AND STATE engineers are shown during the winter at the Lake Jefferson dam as they inspect the spillway and make recommendations for the repairs that are set to take place this coming construction season.

Lake Jeff Dam Declared Safe

By Jeanne Sager
|JEFFERSONVILLE — April 13, 2007 — The dam is safe.
That’s the first thing Barbara and Kevin Gref want people to know.
The second?
It’s going to cost a lot of money to fix.
The Grefs own the 80-year-old dam that keeps Lake Jefferson filled with water, the dam that created the lake from the waters of the Callicoon Creek.
When the June floods went crashing over the stone structure, the water took with it chunks of the spillway, prompting an evacuation of the entire Village of Jeffersonville.
Dam inspectors called in that week put out an all clear, but Barbara said the months since have been filled with engineers “right and left.”
Inspectors dove to the lake bottom in late December, and found what she calls two “caves,” spots where the tremendous force of the water eroded away huge chunks of the dam.
One hole is 3 feet, the other 9 – horizontally.
The good news?
“There’s some erosion, really not as bad as the federal guys thought,” Barbara explained. “From what they told us,” she continued, “there’s no imminent danger.”
But it’s enough to require a repair that will cost Jeffersonville Hydroelectric (which the Grefs own) as much as $200,000.
And it has to be fixed.
So far the Grefs have been “beating the bushes” for funding. They’ve got volunteers willing to do a large portion of the labor – the Grefs were part of a volunteer group that did work on the dam for its previous owner at one time.
But they’ve recently learned that one of their last hopes, the NRCS, has nixed their application.
“It’s a Catch 22,” Barbara said. “If it really was threatening the village, they’d help, but they don’t think the danger is great enough to get involved with government funds.”
In fact inspectors and engineers have told the Grefs and Village of Jeffersonville Mayor Ed Justus that there would likely be little effect downstream if the dam were to break when the creek was low.
If the area were to experience 500-year-flood conditions – like those that battered the dam last June – the effect would be a rise of about 4 feet in the stream below.
“It’s not going to be wiping out Port Jervis!” Barbara said.
The 30-acre lake is small – as lakes go – and shallow. The average depth is 8 feet.
“Our dam is a massive dam on a little lake,” she said.
Built by a private investment group in 1927, its original purpose was to generate hydro-power.
To a small degree it does – powering the WJFF radio station next door to the Gref home.
But Gref said as years went by without a major generation plant running off the dam, it seemed to serve a bigger purpose by providing the recreational use of the lake.
Like half of the dams in America, the Jeff dam is still privately owned.
The Grefs purchased it Dec. 31, 2004 – less than two years before the flood.
Just before the floodwaters came, they had it inspected and passed with flying colors.
Then came the water – lots of water.
It sheared off 1/3 of the concrete overlay to the spillway and created the caverns below the water’s surface.
Repairs, expected to be made this summer, will be done in a two-part process.
Clough Harbour & Associates, the Albany firm that served as civil engineers on the building of Bethel Woods Center for the Arts, has been retained by the Grefs to draw up plans for the project.
The first phase will deal with the subsurface erosion, Gref said. The second will entail the spillway face repair.
The water in the lake will have to be lowered for work to be done.
The dam experts have advised the Grefs that there’s no reason to lower the lake before then.
“The consensus is that it’s not going to break all at once, and it’s probably not going to break at all,” Barbara stressed.
“If we lowered the lake, it’s like a puddle, it fills back up.”
The Grefs are open to questions on the dam – they’ll even allow folks to come down for a tour if they set up an appointment.
Help is also welcome – whether it be in the form of funds or an offer to join the work crew.
Just give Barbara and Kevin a call at 482-3458.