Aging Waterbury Dam May Benefit From Federal Water Infrastructure Act

Dec 16, 2016

The passing of the federal Water Infrastructure Improvements for the Nation Act has been in the news because it authorizes millions of dollars to address the water crisis in Flint, Mich. But the legislation may also help pay for repairs to an historic Vermont dam.

Ten years ago, the Waterbury Reservoir was refilled after major work to repair the structure of the earthen dam. In 2005, while the structural work was wrapping up, repairs were also made to the spillway gates. That work was intended to extend the life of the gates by 10 to 15 years.

Now, more than a decade later, the end of the useful life of those flood control gates is approaching.

Richard Boisvert is in charge of Green Mountain Power’s electricity production at the Waterbury Dam. The state of Vermont oversees flood control operations here. But Boisvert is the person who makes sure everything at the dam is running smoothly.

The dam was built for flood control in the 1930s by the Army Corps of Engineers and the Civilian Conservation Corps. Power generation equipment was added in the 1950s. Boisvert says he works closely with the state’s head dam safety engineer to maintain safe water levels in the reservoir and the Winooski River.

"When the Winooski River gets to 417 feet above sea level, we close the tainter gates and hold back any waters that the reservoir might be spilling," he explains. "And we keep them closed until the Winooski goes below a 417."

The tainter gates that need replacing are open here, at the far end on the right side of the dam.
Credit Amy Kolb Noyes / VPR

The curved tainter gates at the face of the dam are the main way the water level is regulated. There’s also a cone valve that can lower the level of the reservoir without water going over the spillway. But it’s those massive metal tainter gates that need replacing.

Rebecca Ellis is senior counsel for government affairs at the Vermont Department of Environmental Conservation. She’s been working with Vermont’s Congressional delegation to secure federal dollars to help pay for the $40 million project.

She says the legislation that’s awaiting the president’s signature would authorize the federal government to provide up to $10 million to repair dams — like the one in Waterbury — that were built by the Corps of Engineers before 1940 and are not owned by the federal government. But that money still needs to be appropriated.

The Waterbury dam was built under the direction of the Army Corps of Engineers but it is owned by the State of Vermont.
Credit Amy Kolb Noyes / VPR

"It's a two-step process," Ellis says. "This is the first step, it’s the authorization, and then the next step would be an actual appropriation. So that appropriations bill will come up, probably in the spring."

Ellis says if the gates aren’t replaced soon, there will be a big impact on the reservoir.

"The projections are that in a few more years the gates will no longer be operational," she says. "And once the gates are no longer operational, the level of the reservoir would likely have to go down in order to ensure safety."

Ellis says dropping reservoir levels would have an effect on water quality as well as recreation on the reservoir. But, she adds, she’s hopeful the program will be funded by Congress.

"Our Congressional delegation has been great on this issue and working on different ways to find the funding for the Waterbury Dam," she says. "And so I’m hopeful that we’ll be able to get something through."

The Waterbury Dam regulates the Waterbury Reservoir, which is one of Vermont's more popular recreational water bodies.
Credit Amy Kolb Noyes / VPR

That’s good news for the people who use the Waterbury Reservoir, as well residents of the Winooski River basin.

Jason Lisai is the generation manager at Green Mountain Power. Back at the dam, he says Waterbury is one of three flood control sites for the Winooski River.

"After the 1927 flood, they looked at this site, the Wrightsville Reservoir and the Barre retention site," he says. "Those are the three Army Corps sites in the Winooski basin that were constructed after the 1927 flood."

In addition to flood control and power generation, Lisai says Green Mountain Power also maintains the level of the reservoir for recreation.

"From Memorial Day Weekend to Labor Day, we’ve got a certain elevation to maintain," he explains. "Obviously weather events will modify the pond elevation, so we may generate more or generate less to maintain that pond elevation."

Jason Lisai, left, and Richard Boisvert stand inside Green Mountain Power's electricity generation plant at the Waterbury Dam.
Credit Amy Kolb Noyes / VPR

 And, he says, there’s an annual winter draw-down as well.

"And what that does is that gives us the volume available to receive snowmelt in the spring," Lisai says, "which was the intent of this reservoir – for either major weather events and, obviously, snow melt."

And when the snow melts this spring, we should know if the Corps of Engineers dam repair program will be funded.