MIDDLEBURY — Although Otter Creek has been the center of attention for preparing for high waters in Middlebury throughout this soggy summer, the bout of Aug. 4 flash flooding that wreaked havoc on Addison County was primarily the fault of small rivers that crept, and then sprinted, over edges and into yards, driveways and basements. 

“Many (if not all) the major residential flooding in Addison County from both the July and August storms happened along the small streams,” said Andrew L’Roe, emergency management planner at the Addison County Regional Planning Commission. 

As examples, he pointed to flooding on Lower Notch Road in Bristol, Upper Plains Road in Salisbury, lots of places in Ripton, and many spots in Middlebury, including at 83 Court St.

Carol Harden, vice chair of the Middlebury Conservation Commission, noted that although the streams are small, the flooding can be serious.

“They can do a huge amount of damage, as we now know,” she said.

According to L’Roe, their “dispersed and unpredictable” nature can prove challenging for first responders during a storm like the one on Aug. 3 and 4.

“The Middlebury Fire Department was running around the night we had flash floods,” he said. “There was flooding in multiple places in town. And you don’t know where it’s coming.” 

The unpredictability meant that more help was needed than what Middlebury first responders exclusively could provide. 

“That certainly stretches emergency responders,” L’Roe said. “We had folks coming in to help from Bristol, Cornwall, Weybridge — all in Middlebury.” 

Harden noted that at times when they don’t warrant the attention of intercounty first responders, small rivers can prove deceptive. 

“I think people need to be more aware of the small rivers … some of these things are dry a lot of the time, or just carry a little trickle, and so we tend to not think about them,” she said.  

However, she said it’s important to understand that their force can quickly become powerful.

An additional concern to consider is that the flow of a small river can be easily halted by accidental dams, resulting in an inevitable big burst that can prove problematic down the road. 

“It doesn’t take much to block the flow temporarily,” Harden said. “If there’s a culvert, or even a little bridge, or a tree down across, it only takes a little bit of you know — another tree, trash cans, and trash, some brush, whatever — to create a small dam and actually impound water, and then that usually exceeds the strength of the small dam and then releases downstream,” Harden said. 

“And so you get even more than just the rain itself. You can get these extra spurts of water, if it’s been held back and then it breaks through.” 

Harden wants people to appreciate the danger that flooding poses, even if it is just a little stream or brook.

“People need to realize these little streams and even ditches and things can carry a lot of water. And I think as we live in this landscape, we need to just make sure that we give the streams some space,” she said. 

And although littered throughout the state, the flooding behaviors of small rivers are an ecological challenge that has yet to be widely explored, said Ned Swanberg, regional flood plain manager for the Department of Environmental Conservation. He said small rivers are a leading cause of flooding damages throughout Vermont.

“A lot of the work around consideration of flood hazards has come out of the National Flood Insurance Program. And that has come from a legacy of damage across the country, and particularly around the experience of large rivers,” he said.  

RIVERS WANT TO MOVE

Because the National Flood Insurance Program maps do not adequately account for this geographic feature, the state has implemented another option for prevention: modification of zoning bylaws to include in river corridors protections to “an area around the stream or river that protects the form of the river as it meanders through the landscape, through the valleys.”

“Rivers always want to move,” L’Roe explained.  

Zoning bylaws that implement development restrictions around small rivers could possibly reduce future flood damages of the magnitude experienced on Aug. 3 and 4. 

Leaving undeveloped space around the river allows it to pursue a zig-zag path down a valley, rather than flowing straight down. If it is able to zig-zag, the speed of the flow and the power of the river is reduced.   

“When the stream channel becomes straightened, much like a skier coming down the mountain, it comes down faster, and it causes more damage, it arrives with more water and more power, all the way down the hill and into the valley,” said Swanberg. 

By limiting development near small streams, it’s possible to “create protected space where it’s still available, so that the river can find its least erosive path down the valley,” he said.  

The only towns in Addison County that have the “interim” River Corridor bylaws are Lincoln, Ripton, Granville and Orwell, L’Roe said. 

“Which also means they’re the only towns reimbursed at the maximum post-disaster (Emergency Relief and Assistance Fund) rate (17.5%), which can mean an additional $50,000 that the town wouldn’t have to come up with if they suffer $1 million-plus in damages,” he added. 

Pursuing this prevention effort could be in Addison County towns’ best interest, financially and otherwise, according to Swanberg and Harden. 

Flooding issues aren’t going to disappear.  

“The more the atmosphere warms up, the more moisture it can hold. And it’s not just the atmosphere over Middlebury and Addison County. The whole world has warmed up quite a bit,” Harden said. 

“As we look around the country and the world, we are seeing rain events that we would have thought were really unusual in the past, and they’re kind of all over the place. And they happen more than once. We’ve had a number of hard rains this summer. So I think in a warming world, this is what we have to deal with in the future.”

Swanberg agreed we can expect more of this flooding in the future, so it’s important we start thinking as a collective, rather than as individuals. 

“It may not always hit in the same place,” he said. “We need to be working together on common standards that are going to support all of us. When disasters come, they can be seriously harmful to individuals and families and businesses. But they’re also harmful to all of us, as federal taxpayers, as state taxpayers, as community taxpayers,” he said. 

“We need to be working together to actually reduce our risk. Our risk is not going away anytime too soon.”