The Aftermath of the Great Floods of 2023

Never have I felt more connected to the length and breadth of our watershed following the flooding of July 2023. If more evidence was needed to remind us of the need for a watershed-wide strategy toward environmental planning and protection, the recent storms and rains in the north of New England provided just that. While floods raged in Vermont, uprooted docks floated downstream in Connecticut, one with several boats still moored to it. Fields in the flood plains of Massachusetts were flooded, ruining crops. Roads were washed out or rendered impassable throughout the watershed, but especially in Vermont and New Hampshire. Trees and stumps, sewage overflow, and other detritus and pollution from the far north floated down into the estuary and out into Long Island Sound.

Chance Lister, left, and Parker Cutting, of Green Mountain Power, checked the substation in Taftsville, Vt., after heavy rains caused flooding throughout the Twin States on Monday, July 10, 2023. The Ottauquechee River was running high and fast near the substation. Image Credit: Valley News - Jennifer Hauck.

These floods in particular raised the obvious questions: What is different today from previous storms—especially the Great Flood of 1927 which severely impacted Vermont—from major flood events in 1936 and 1955, and from Tropical Storm Irene in 2011? After Irene, what steps were taken to prepare for future storms? Were these steps helpful? And how do watershed residents, nonprofits, and government entities prepare for the future? Will we see more of the same, or are things going to be even worse?

To understand what happened this summer and what lies ahead, Estuary called on Dartmouth Professor of Geography Frank Magilligan. Cautioning that it’s still early to assess the entire matter, he explained it this way: “It was a wet spring…and a wetter summer.” The ground was already saturated when the torrential rains came in early July, so the water had no place to go. Montpelier and Manchester, Vermont, were both flooded by ten inches of rain in two days.

Following Tropical Storm Irene (downgraded from Hurricane Irene before it reached New England), Vermont has been especially proactive with long-term planning for protection from future floods. The state focused on the need for improved infrastructure, including roads, bridges, and homes in the cycle of “flood-destroy-rebuild” then “flood-destroy-rebuild” again. To mitigate against such crises, 150 homes in the flood plains have been bought out by state organizations in the past ten years.*

The Connecticut River Conservancy also engaged in flood mitigation efforts throughout the watershed by, among other measures, planting thousands of trees in flood plains to slow the flow rates and reduce erosion and by identifying undersized culverts to be replaced with larger ones to carry the runoff from farms and protect rural roadways. However, countless fish habitats have also been compromised for which there are few remedies.

Left: Bridge of Flowers in Shelburne Falls, MA, July 2023 flood. Right: Ludlow, VT, Route 100 damage. Image Credit: John Burk.

In New Hampshire, the Department of Environmental Services (NHDES) created the Post-Irene River Response Team (now known as the New Hampshire Silver Jackets). This team focused on improving the state’s organizational response to floods; water quality issues such as contamination due to runoff; and infrastructure, especially culverts. One program has been tasked with assessing the flood-related resilience of every culvert in New Hampshire by 2026. With over 10,000 culverts assessed so far, 23 percent pose unacceptable failure risk.

In Massachusetts, farms operating with the rich alluvial soils in flood plains have been inundated, with lost crops for the summer season and, in some cases, inability to plant for the fall season.

The main cause of the extreme weather is climate change in the form of rising temperatures. “A warmer atmosphere retains more moisture,” warns Professor Magilligan. He adds that as it’s going to continue to get warmer, we can expect more flooding rains and even more violent weather in the future. In his words, we have to prepare for “the new abnormal.” No doubt, response teams throughout the watershed will reassess their current programs and shift priorities to reflect new information obtained following the floods of 2023.

A few days after the heavy rains fell in the upper valley, my wife and I were watching the still-swollen river flow past Old Lyme, Connecticut. In an outgoing high tide surge of five knots, a pair of seals suddenly appeared across the harbor steaming by at eight knots, with the extra three knots provided by the seals themselves. They weren’t just swimming. As they sped past, they were barking—barking for sheer joy as they escaped the upriver chaos and looked forward to taking refuge with their friends and cousins on Plum Island in the comparative calm of Long Island Sound. As a naturalist of record since 1939, I know these things.