The Palisades Interstate Park Commission (PIPC) announced plans in March 2018 to deconstruct the worn dam and de-water the lake, which is part of the Minnewaska State Park Preserve, for safety reasons. However, local residents fought back, commissioning environmental studies, lobbying their state representatives and demanding additional cost estimates, arguing the dam should instead be repaired and the lake saved.
The dam would cost between $2.9 and $3.8 million to repair, according to the new estimates, which come from three proposals in a PIPC-commissioned engineering report. The outside range of the three estimates runs from $2.3-$4.9 million, according to the report, which is still in a draft form and not yet publicly available but has been reviewed by The Other Hudson Valley.
This is far lower than the $7 million to $9 million estimate presented to local residents in the March 2018 letter announcing the PIPC’s intention to de-water the lake, and significantly lower than the $5-$7 million price tag estimated by PIPC Superintendent Jim Hall to The Other Hudson Valley last November.
Removing the dam and de-watering the lake would cost between $1.4-$2.2 million, according to the report.
Morey Gottesman, the president of Friends of Tillson Lake, which was formed in response to the potential de-watering, celebrated the new estimates, pointing to the smaller gap between the cost of deconstructing the dam and repairing it.
The state Department of Environmental Conservation, which oversees dams in New York, must still approve the report, but “there should be no significant reason for them to reject it,” Gottesman said.
“So we await that as the final dot over the i,” he said.
However, Superintendent Hall was more cautionary about the repairs moving forward.
“We have to determine whether the approach this engineering firm has taken is acceptable and appropriate,” he said. “So some of that means having some conversations with DEC as to whether or not the approach [the engineering firm has] taken meets all their standards – we’re going to have to undertake that first before we make any decisions.”
After Gardiner residents received letters last year from the PIPC informing them the cost of repairs would be an unattainable $7-$9 million and therefore steps were being taken to remove the dam, Gottesman and others requested cost estimates for fixing the dam through the Freedom of Information Law (FOIL).
They received a 2012 cost estimate that put the repairs at about $2.7 million, and a 2016 estimate that put the cost at about $2.8 million, though neither of these figures take into consideration contingencies.
The discrepancy between the FOILed estimates and the $7-$9 million cited in the letters was because the former was based on a 2012 engineering assessment that was cursory, Hall said last year, a “very brief evaluation of some alternatives.”
However, one of the alternatives proposed in the just-released report is “largely” the same as the 2012 engineering assessment, according to the report, and comes up with a figure more in line with the FOILed estimates — $3-$4.9 million.
About $1.5 million was authorized from last year’s state Parks, Recreation and Historical Preservation budget for studies and to remove the dam, Hall said, a proposal that did not come to fruition.
The just-released report, penned by Schnabel Engineering, also makes clear the dam’s deficiencies, reiterating that repairing or deconstructing the dam is necessary.
Though the report states the dam is “stable,” some of its components do not meet DEC guidelines.
“We consider Tillson Lake Dam to be in a condition whereby its deficiencies are of such a nature that the safety of the dam cannot be assured,” the report summarizes.
The crumbling spillway needs to be repaired or it will eventually topple and cause the dam’s embankments, which are already in poor condition, to slump, according to the report.
The report also models how downstream areas would be affected in two flooding scenarios, concurring with the dam’s designation as “high hazard” – a classification based on how much damage would occur if the dam was breached, as opposed to how likely this is to happen.
Two houses downhill from the dam would be flooded with 3-4 feet of water if the dam breached during normal weather conditions, according to the report. If the dam breached during a “50 percent probable maximum flood” – 36.3 inches of rain during a single storm event – three houses would be inundated with between three and nine feet of fast-flowing water, putting their occupants in danger.
If a 50 percent probable maximum flood occurred at all, some water would overtop the dam’s left embankment but not over the majority of the dam, and this overtopping would only occur for two hours, according to the report, making this part of the dam “marginally compliant.” However, the three alternatives for repairing the dam all include improvements to fix this.
If the DEC accepts the report, the lake could still be de-watered – the report presents the alternative of taking down the dam – and funding would still need to be acquired for repairs.
There is not enough money in the Parks budget to pay for the repairs, according to Hall, and the capital improvement would need to be worked into the next State Budget.
State Assemblyman Kevin Cahill, whose district includes Tillson Lake, said in an earlier interview these types of items were not successful “most of the time,” as billions of dollars more are requested each year than the budget contains.
However, Cahill was going off the former, higher cost estimates at the time.
Friends of Tillson Lake has yet to plan how to lobby for the funding, but Gottesman said they would be communicating with their state Senator, Jen Metzger, and a press conference was in the works.
“She’s been really, genuinely involved with this,” he added.
Metzger called the substantially lower estimates “great news” in a statement.
“…it is my hope that funding will be available to repair the dam and maintain this valuable community and recreational asset. Should DEC agree with this…revised cost, we’ll need to work with Parks and Recreation to identify possible funding for these much-needed repairs,” according to the statement.
In the meantime, the Friends of Tillson Lake are continuing to pursue a second route: getting 12.4 or more acres in and around the lake officially designated at wetlands, a size causing environmental protections to kick in, and make de-watering the lake – which would desiccate the wetlands – more difficult to pursue.
The Tillson Lake Dam has failed twice: first in 1938, when farm equipment, livestock, and several local bridges were lost, and again in 1955, though no one was injured or killed in either instance.
The privately-owned lake and surrounding landscape was purchased by two open-space groups in the 2000s, then was passed to the state, where it became part of the Minnewaska State Park Preserve.
The Friends of Tillson Lake take particular umbrage to a potential de-watering because the Minnewaska State Park Preserve’s Master Plan states the lake will be maintained and improved, including the construction of a parking lot.
A dirt lot is the only place to park near the lake, but Gottesman said he’s been seeing more cars there as of late. School’s out, but residents have also been promoting the lake with events, such as a free fishing day June 30, where residents supplied gear to anyone who wanted to cast on the lake.
“It’s not valuable unless people use it,” Gottesman said.
Afterword: Who goes to Tillson Lake?
I was talking to a friend of mine from New Paltz (or a ‘newper’) a few days before writing this article, and she mentioned she had gone swimming in Tillson Lake the weekend before.