Vermont Storm Exposes the Strengths, and Limits, of New Flood Defenses

Vermont, a state known for peaceful green mountains, grazing cows and tidy covered bridges, is not often seen as a place where mudslides threaten highways, rivers churn with debris and murky, propane-fouled floodwaters fill downtown streets.

But those kinds of images of destruction were seared into memory when Tropical Storm Irene battered Vermont in 2011, and led to a drastic reassessment of how to protect the state against storms supercharged by a warming climate.

A forceful storm walloped Vermont again this week, causing severe flooding, damaging thousands of homes and businesses, and revealing the effectiveness of some mitigation measures taken since Irene. At the same time, officials and experts said, the storm demonstrated the need for ongoing adaptation, as storms become more extreme and less predictable.

“You hope that every event like this keeps people alert, and thinking of the future,” said Frank Magilligan, a Dartmouth College geography professor and river scientist who has studied flood hydrology and the regional effects of Irene. “It’s not going to be a one-off, and you can’t put your head in the sand.”

No injuries or deaths have been reported, but state leaders said on Wednesday that the full scope of the damage from the latest storm was yet to be assessed, with lingering flooding in areas, dozens of closed roads and some communities almost completely cut off. More rain is forecast in the days ahead, raising concerns that some trouble spots could soon flood again.

Yet even as the emergency response continued, some leaders called for more long-term planning to build on the lessons of the 2011 storm and face with more urgency the unpleasant likelihood that devastating floods will occur more frequently.

“I have seen an increase in records being broken, records that have stood for decades or even a century,” Representative Becca Balint said at a news conference in Berlin, Vt., on Wednesday. “We really need to start to better understand what it’s going to look like 10 or 20 years from now, so we can use our mitigation dollars to help reduce those impacts and help these systems be more resilient.”

After the devastation 12 years ago, from a storm that killed six people in the state and caused millions in damage, state and local leaders pushed ahead with changes designed to ensure that future storms would do less damage.

State engineers studied the 34 bridges that Irene had destroyed, and replaced them with new ones that minimized the number of large support piers in the water, which had blocked debris flowing down the rivers and caused it to build up and damage roads and bridges. Only two bridges are known to have been destroyed in the storm this week, said Joe Flynn, state secretary of transportation.

To move more people out of harm’s way, the state increased restrictions on building in flood plains, and began a buyback program that has removed 150 homes from those areas, Dr. Magilligan said. This effort mitigates risk in two ways, he said: “It gets people out of danger, and it opens up more places for the water to go, slowing down the flow.”

But many homes remain near rivers. And even some homeowners who rebuilt after Irene, and who took pains to add new safeguards, found this week that they were not enough. Bill Korzon, 68, a resident of hard-hit Ludlow, said he raised his mobile home by 16 inches after it took on four inches of water in the 2011 storm, warping and buckling floors and resulting in an infestation of mold.

Nonetheless, the house flooded again on Monday with at least an inch of water, and by Wednesday the floors were already beginning to buckle. Mr. Korzon said he had no flood insurance.

“It’s a lot, and you get tired of it,” said Mr. Korzon, a longtime ski instructor at nearby Okemo Mountain Resort who moved to Vermont from Connecticut nine years ago when his wife retired. “I’m going to fix this and do everything I can. But I was 56 last time and now I’m 68 — it’s a lot different.”

He said he and his wife may consider leaving Vermont, a state they have long loved for its peace and quiet. “Maybe we move down south,” he said.

In Johnson, 100 miles to the north, Joie Lehouillier, an organic farmer, said she, too, had made changes after Tropical Storm Irene — relocating some fields, storing equipment on higher ground and digging trenches to hold water.

None of it made much difference this time, she said on Wednesday as she surveyed the muddy land and assessed her lost crops. “When it hit, it happened so fast,” she said. “Even if we had anticipated that, I’m not sure we could have done anything.”

There was some good news for the state’s farmers: Vermont’s agricultural lab, which was destroyed by flooding in 2011 and rebuilt on higher ground, escaped this week’s storm unscathed. As a result, it remained open, allowing for immediate soil safety testing in the wake of the flooding, said Anson Tebbetts, Vermont’s secretary of agriculture, food and markets.

“We learned our lesson there,” he said, “and protected a valuable asset.”

In Waterbury, one of the towns that was hit hardest by Irene, there were plenty of signs of the latest storm on Wednesday: a saturated ball field, bushes encased in mud, and residents in waders filling dumpsters. But the town’s wastewater pump station — rebuilt with new flood-proof technology after it was devastated in 2011 — worked “flawlessly” despite a tenfold increase in the water flow, said Bill Woodruff, the town’s public works director.

That investment, along with a new municipal building rebuilt since 2011 on higher ground, helped the town of 5,000 people keep functioning.

In a landscape like Vermont’s, however, not every risk can be mitigated.

“You can’t change elevation,” Mr. Woodruff said. “We’re built in a river valley, and you can’t change that.”

Reporting was contributed by Richard Beaven, Abby Goodnough and Hilary Swift.