Making Peace With the River: Prevention, Floodproofing, and Letting the Water Flow

Kip Roberts, co-owner of Onion River Outdoors, stared hard at the TV camera, the strain clear on his face. Next to him was the still-raging North Branch that just days before had wiped out the store and much of its inventory.

“A friend told me a long time ago Montpelier seems like a town that’s at war with its rivers,” Roberts said in the short video by Vermont Public. “And it’s kind of true. We have boxed this river in and it has nowhere to go but into our businesses and homes.”

How to make peace with the Winooski? The question comes up again and again in conversations and community forums. 

How can we live more in harmony with a river that is increasingly prone to catastrophic flooding caused by climate change? Can we let the Winooski revert to more of its natural course? And even: Should we abandon downtown Montpelier and relocate the business district uphill?

Mike Kline knows rivers and how they flood. The former rivers program manager for the state Department of Environmental Conservation, Kline has many of the same questions and maybe even the beginning of a few answers formed by years of experience in river science.

The first thing to realize, Kline said, is how much humans over 250 years have changed rivers and increased their flood potential. We’ve built dams, dredged rivers for gravel, deforested their banks, hemmed in their meanders, even dredged new channels. And then we’re surprised they flood after all those alterations. Some of the answers for the future may involve undoing the damage of the past. 

Lessons from Irene 

I met Kline recently for a walk along the Winooski in Montpelier. He recalled that Tropical Storm Irene in 2011 helped reshape thinking statewide about how to live with rivers.

“Irene was a real interesting inflection point, I think, for Vermont. Up until that time, and I think in the cultural DNA still, there was this idea of putting the rivers back where they belong, digging them deeper,” he said. “What we have learned … is that some of those practices, those historic practices of channelizing the river, were actually exacerbating the vulnerability of our communities and the damages that we were seeing.”

Kline said the basic lesson from fluvial geomorphology — the science of how rivers move and change across the landscape — is that rivers need room to move. When a river can slow down and dissipate its energy as it spreads across its historic floodplain, it is less likely to cause damage. 

How do you do that in Montpelier? “It’s a hard question,” said Kline as we walked along a section of downtown where the river is lined with huge stone blocks forming a wall at least 20 feet high. “Because we’ve created a little human canyon down here that’s not left us many options. From an erosion standpoint, this is pretty good. From an inundation standpoint, no. The water has nowhere to go but up and out.”

One answer is to look outside of downtown Montpelier for places where the river can reclaim its former floodplain. 

Ned Swanberg is the state’s regional floodplain manager. He spoke at a recent community forum about the importance of watershed-wide solutions. 

“We’re not alone. We’re part of a watershed. Protecting floodplain functions and the room needed by the river is really critical before the water shows up in town,” he said.

Floodplain Access

Some lessons for floodplain management may be found in Northfield, upstream from Montpelier on the Dog River, a major tributary of the Winooski. 

After Irene, seven houses along the Dog River in Northfield were demolished and a small park was created in the greenspace. The river’s banks were lowered to help the stream slow down and access the floodplain. A federal program helped pay for the buyouts. 

Michelle Braun is now executive director of Friends of the Winooski, a local river advocacy group. But back in 2011 she was Northfield’s land use manager and helped facilitate the buyouts. She said engineers studying the impact of the July flood estimate that the floodplain project along the Dog helped reduce flooding in town by six inches.

“Six inches doesn’t sound like a lot. But if you’ve ever had six inches of water on your first floor, it makes a tremendous amount of difference,” she said.

Kline pointed to other floodplain restoration projects around the state. In Brattleboro, the Vermont River Conservancy bought 12 acres along the Whetstone Brook just upstream from downtown. Contractors this summer finished removing a berm so the flood waters of the brook can now flow onto the land. 

“It’s estimated to receive the Whetstone Brook under flood and significantly drop levels in the business district of Brattleboro,” Kline said. 

Kassia Randzio, development and operations director for the Vermont River Conservancy, said that the Whetstone project emerged after Irene as Brattleboro looked for ways to make the next flood less severe. 

“Just as central Vermont communities are doing right now — so it’s a great opportunity to showcase flood recovery in action,” she said.

Another post-Irene project in Bennington allowed the Roaring Branch in that city to reach its former floodplain, Kline said. 

“It took a number of years. And they had the space to do that. But the point I’m making is that sometimes a small, few pieces of floodplain can make a difference,” he said. 

And in some river systems, big pieces of undeveloped floodplain can make a huge difference. Kline and others said the best example is a series of wetlands and agricultural fields along the Otter Creek between Rutland and Middlebury that served as a natural buffer during Irene and the July storm. 

“The floodplain complex between Rutland and Middlebury protected property and infrastructure from Middlebury all the way to Lake Champlain, including in New Haven, Weybridge, and Vergennes,” according to a recent state report. 

Kline said similar opportunities are rare outside the Champlain Valley. In central Vermont “the hills are steep, we have narrow valleys,” he said. “But we can get some flood relief by accessing some of the floodplains rivers have created over time.”

Even in Montpelier there are potentially places for the river to possibly access the floodplain, said Swanberg, the state’s regional floodplain manager. “We can set back some of the channelization and make some room,” he said, although in some of those areas the river is blocked by berms built by the railroad. 

Floodproofing buildings and installing more resilient infrastructure — including bridges and culverts — is also key to reducing damage during the next flood event. 

Agency of Natural Resources Secretary Julie Moore also cited the “build back better” lesson learned after Irene. In many areas, larger culverts installed after that 2011 flood withstood the July storm, she said. 

Irene also significantly damaged the state office complex in Waterbury. Post-Irene, a network of tunnels underneath the buildings was filled and the complex was floodproofed by elevating heating and electrical systems.

 “To me, the Waterbury complex is an absolute success story. It doesn’t mean there was no flooding in Waterbury,” she said. “But the damage was much more modest than it was during Irene and that’s a reflection of the good work that took place over the last 11 to 12 years.” 

For Moore, that’s the silver lining left by Irene’s storm clouds. “It doesn’t mean there aren’t hard choices, but the fact of the matter is we are able to really improve landscape level resilience,” she said. 

Dam Removal

The Winooski in and upstream from Montpelier is also altered and blocked by a number of unused dams. Removing those structures could help in future flood events, advocates say.

Four dams are now being studied for possible removal: the Bailey dam, just upstream from the Shaw’s supermarket, the Trestle dam upstream of the North Branch’s confluence with the main stem, the Pioneer Street dam, and the Hidden dam, located in East Montpelier about 2.75 miles upstream of the Pioneer Street structure.

It’s a common misperception that these dams help control flooding, but the opposite is true for these abandoned, often crumbling projects, said Michele Braun of Friends of the Winooski. “If it’s not specifically designed to store water in a flood event, it’s not going to store water in a flood event,” she said. “It’s likely to make flooding worse by … inhibiting the river from behaving the way it naturally would.” 

The Vermont River Conservancy is leading the dam removal project using funds from the Lake Champlain Basin program.

Removing dams takes time. Braun estimates even simple projects can last three to four years from start to finish. They’re also costly with many variables to look at. At the Pioneer Street dam, a big concern is potential toxic contamination left in upstream sediment by a coal tar plant once located at the Wind River Environmental site.

This dam “is the oldest and most decrepit of the four dams and is likely impounding hazardous sediments,” according to the Conservancy’s “request for proposal” (RFP) to design the removal. While the land on the site was cleaned up “remediation did not fully extend into the river; high-levels of these same industrial contaminants are likely accumulated in sediment behind the Pioneer Street dam.”

There are about 65 unused dams in the Winooski watershed, Braun said. Technical hurdles — and significant expense — lie ahead. Yet removing dams could be part of the answer to letting the Winooski behave more like a natural stream.

The audience gathered in the Vermont House chambers Aug. 22 for a community forum raised questions about dam removal, managing the river upstream, and reconfiguring existing flood control projects such as the Wrightsville dam on the North Branch. Among the questions: Is it possible to build catchments in the dozens of tributaries in the Winooski headwaters? What about lowering the water level in Wrightsville before the flood? Can we encase the North Branch in a tunnel so it doesn’t flood downtown?

State climatologist Lesley-Ann Dupigny-Giroux told the group that these questions will help inform the work that lies ahead for the scientists, engineers, and public at large.

“Meetings like this are the most important thing for us as scientists,” she said. “I just want to lift up all the things that were said tonight because they will help us all.”

Mike Kline said a team of experts could use river flow models and other research to search for answers. “It’s time to set those models back up and start asking some new questions, some of the questions the public is asking now.”

Moving Downtown?

We’ve stopped walking along the bike path and look down at the Winooski that flows high and muddy weeks after the flood. It’s a rare moment of sun in this summer of endless rain. What about downtown, I ask: can Montpelier as we know it live with the river as we have it?

 “When you see the downtown flood three times in three decades, you have to ask that question: can we endure this in another 10 years, and another 10 years after that,” Kline said. 

“So, it is time to start asking these really big questions: can parts of downtown be floodproofed further? That’s one alternative. Can parts of downtown be moved to a higher location, in addition to some of these river and floodplain restoration projects that we’re talking about?”

Floodproofing is actually required for damaged properties under Montpelier’s “River Hazard Area Regulations.” These measures include either fully protecting basements from water inundation or moving electricity panels, HVAC, and fuel systems out of basements.

Moving downtown is another issue. It would obviously be hugely expensive and would mean abandoning the historic charm of the buildings in the city’s urban core. 

Michele Braun of Friends of the Winooski, sighed when asked: With her expertise, how should Montpelier live better with the river. Should downtown be moved and let the river be?

“People do keep asking me that and it’s just really hard because the river is just really channelized and we’ve really built so tight into the river,” she said. “The expense of moving is extraordinary and the cultural impact of moving may be unacceptable.”