Helene’s flooding is a reminder of Appalachia’s growing risk from violent storms

HENDERSONVILLE, NC (AP) — Hurricane Helene dumped trillions of gallons of water hundreds of miles inland, devastating mountain communities far from the threat of storm surge or rising sea levels. But that distance can hide a history of flooding in a region where water flows into populated cities hidden in steep valleys.

“We almost always associate the risk of flooding with hurricanes and coastal storm surges in Florida, Louisiana and Texas,” said Jeremy Porter, head of climate implications research at First Street, a firm that analyzes climate risk. “We don’t think of western North Carolina and the Appalachian Mountains as an area that is at significant risk of flooding.”

More than 160 people died in six southeastern states. Floodwaters cut roads, knocked out cell service and pushed debris and mud into towns.

Parts of the Blue Ridge Mountains, where fall colors are just beginning to break through, were hit particularly hard. In tourist-friendly Asheville, officials warned it could take weeks to restore drinking water. Orange-brown mud stands out on the riverbanks, a reminder of how high the rivers swelled.

Hurricanes moving inland with strong storms have created disaster before. In 2004, for example, four people were killed in western North Carolina by a debris flow caused by 12 inches of rain that fell from Hurricane Ivan.

It’s difficult to quickly determine the exact role climate change played in certain disasters like Hurricane Helene, though a quick review by researchers at Lawrence Berkeley National Laboratory found that it likely increased rainfall totals in some areas.

Scientists say global warming is helping some large hurricanes become wetter.

In addition, a warmer atmosphere can hold more water, fueling intense storms, although the mountainous terrain of the Appalachians complicates the interaction between weather events and climate change, according to Jim Smith, a hydrologist at Princeton University.

Dave Marshall, executive pastor at First Baptist Church in Hendersonville, North Carolina, said he was “totally shocked” by the storm’s devastation that overwhelmed local services. On Tuesday, he was overseeing a busy donation center offering essentials such as propane and food, noting that he had expected rain and maybe a day or two without power.

“No one was prepared,” Marshall said. “We are shocked and devastated. Everyone knows a friend or family member who has lost a loved one.”

Porter, the climate risk researcher, said the Federal Emergency Management Agency’s flood maps used to determine the most at-risk areas where certain homeowners are required to purchase flood insurance have their limits. He said the maps take into account a specific range of flooding and underestimate the risk of flooding in some areas — and that the problem is particularly pronounced in parts of Appalachia.

“We’re seeing more and more of these heavy rainfall events, exactly the type of events that this region is susceptible to,” Porter said, adding that the flood zones on FEMA maps do not capture these changing conditions.

FEMA recently updated how it prices flood insurance to account for more types of flooding to accurately base costs on flood risk. The agency says flood maps are not meant to predict which areas will flood. Instead, they help define the most at-risk areas for planning and insurance needs, FEMA said.

“Floods don’t follow lines on a map. Where it can rain, it can flood,” said Daniel Llargues, FEMA spokesman.

Before Helene, federal forecasters told residents in western North Carolina that the flooding from the hurricane could be “one of the most significant weather events that have occurred” since 1916. That year, a pair of hurricanes in one week they killed at least 80 people, and the community of Altapass received more than 20 inches of rain (50.8 centimeters) in a 24-hour period.

“It’s not a big surprise,” Smith said. “But what happened in Helene happened in 1916.”

Photo: Ben and Becca Phillips deal with the mud left by Hurricane Helene that flooded their home in Marshall, North Carolina. (AP Photo/Jeff Roberson, File)

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