Posted on August 20, 2024
In light of many recent storms causing severe river overflows across Vermont, one being just last week, people have been suggesting and asking why not dredge the rivers.
“It is very intuitive and seems very logical at first, but there’s actually a lot more to it,” said Shayne Jaquith, a river scientist at Nature Conservancy Vermont.
Scientists said while making rivers deeper to hold more water seems like a smart idea, it actually isn’t because rivers are only meant to hold a certain capacity.
“Really, what the science shows is a lot of the damages we’re seeing today are largely a result of historical management practices of dredging, straightening, and armoring our channels,” said Jaquith.
Experts added once you make a river hold more water then it’s capacity, it can make flooding events even more extreme and cause danger farther down the river.
“The force and the weight of that water will dig at the soft sides of the river, and the sides will fall in, the river will widen, and you will be in worse shape than you began,” said Michele Braun, the executive director of Friends of the Winooski River.
The state agrees and said with experts, while dredging can be beneficial at times, it can’t be the full solution.
“Dredging needs to be done strategically so it does not destabilize rivers ahead of the next flood. Without thinking about the whole river system, an approach that might better protect your property could have catastrophic consequences for your neighbors,” said Julie Moore, the secretary of the Agency of Natural Resources.
Scientists and the state both think floodplains are a stronger option.
“The most effective way to have room for our floodwaters is to set aside and restore places for water to spread out as opposed to digging deeper,” said Moore.
For some who have experienced the detrimental flooding over the last few years a solution can’t come quick enough.
“You know I live in Montpelier and my town was completely underwater last year, if I thought dredging would make my town safe, I would certainly want to do it but I know that it won’t,” said Braun.
The state also said that since many floodplains have been built on and developed, that’s one of the reasons some of the same people often experience flooding every time their respective river jumps its banks. However, they’re working on ways all across the state to reconnect floodplains to rivers or find other ways to hold water outside of the river.
