Mid-Atlantic
In 2016, Ellicott City, Maryland, was hit with a "1,000-Year Storm." Less than two years later, it happened again. Alicia Tatone

In a Town Shaped by Water, the River Is Winning

Storms supercharged by climate change pose a dire threat to river towns. After two catastrophic floods, tiny Ellicott City faces a critical decision: Rebuild, or retreat?

ELLICOTT CITY, Md.—The floor beneath Sally Tennant’s feet was thumping, as if it had a heartbeat—an irregular one, with each thud getting louder and more violent. When she looked out the window of her store, she discovered why: A river of muddy water was gushing down the street, and it was sending tree branches, rocks, pieces of fencing—anything the water swept up—crashing into the side of the building.

It’s happening again.

Tennant opened the front door of her craft and jewelry store, Discoveries, and did what safety officials say you should never do during a flash flood: She went into the water. It was nearly knee deep, flowing down Main Street and rising quickly. The rain was unrelenting: a ferocious, sustained downpour.

But the water in the street had not reached the Forget-Me-Not Factory yet. The gift shop across the street occupied a four-story building faced in sturdy granite, and Tennant decided to head there rather than risk getting trapped in her two-story brick and wood structure.

The refuge Tennant found in her neighbors’ shop didn’t last long. Soon, owners Barry and Nancy Gibson were trying to stop water from rushing in through both the front and back of their store. Runoff from the steep hillside behind the building poured into multiple floors at once. And as the water levels rose, those trapped inside realized that their best escape route was to climb up the hill.

The Gibsons led the group, including one shop employee, up the muddy hillside. The rain was so intense that Tennant couldn’t see more than a few inches in front of her. Sheets of water cascaded down the hill. With each labored step, she felt herself sink deeper into the mud. It ate her shoes, but she kept climbing. “I thought I was going to die of a damn heart attack,” Tennant recalls.

Beneath her, lower Main Street had become a raging river that engulfed the first floor of most buildings. About 50 people inside Tea on the Tiber, a Victorian tea house that sits over a branch of the stream that courses beneath the town, now huddled on the second floor, listening to the river tear the dining room apart beneath them. A woman named Jane called 911 on her cellphone.

“Are we going to die?” she asked the dispatcher.

***

The Memorial Day weekend downpour that struck Ellicott City, Maryland, on May 27, 2018 was a “1,000-year storm”—a rain event so intense that, in any given year, it has a 1-in-1,000 (or 0.1 percent) chance of happening. On that day, back-to-back thunderstorms dumped more than eight inches of rain in just three hours, overwhelming the three streams that converge on the town’s Main Street and sending water crashing down the hill. By evening, according to rain gauges to the north, as much as 15 inches had fallen. The resulting flash flood devastated the historic downtown and killed Eddison “Eddie” Hermond, an Air Force veteran and Maryland Army National Guardsman who was swept away trying to rescue a woman trapped by the floodwaters.

Flooding in Ellicott City is hardly new—the mill town has had at least 18 major floods since it started recording them in 1789. This one, however, was different: It was the second such 1,000-year storm in less than two years. On a Saturday night in July 2016, thunderstorms dropped six inches of rain on the city, triggering flash flooding that killed two people and caused an estimated $22 million in damages, plus $42 million in lost economic activity. In 2011, Tropical Storm Lee generated yet another serious flood. Collectively, the trio of disasters finally forced Ellicott City to take an anguished look at just what its future is likely to look like.

The warming world is a wetter one: For every 1° F increase in temperatures, the atmosphere holds about 4 percent more water vapor. That means heavier and more frequent rain in some places. Already, flooding is the most common natural disaster in the U.S., accounting for nearly three-quarters of presidential disaster declarations over the last decade. One recent report estimates that 41 million people live in 100-year flood plains across the U.S., more than triple the number the Federal Emergency Management Agency predicted in their most current flood maps.

The rising oceans that imperil cities like Miami and New York may grab more headlines, but urban and inland flooding happens almost daily in the U.S., according to the first-ever national assessment of such events. From Texas and Louisiana to the upper Midwest, river towns and cities now find themselves reshaped by chronic inundation; the waters that were once their economic lifeblood are now threats to life and limb.

But it wasn’t just climate change that made both the 2016 and 2018 Ellicott City floods so lethal, many locals believe: Some blame the decades of suburban development patterns in the hills above the historic town, which replaced forested slopes with impervious surfaces that sluiced stormwater into town.

After the 2016 flood, county leaders debated a range of costly mitigation strategies, which involved constructing more stormwater ponds, building stream walls, widening the culverts beneath the streets, and building parking garages engineered to catch stormwater. A moratorium on new development was proposed, but didn’t pass.

That debate took on a fresh urgency after the Memorial Day disaster, which emphasized how fundamentally vulnerable the town was. In its third century, a picturesque mill town faces a profound reckoning, one that mirrors the challenge so many human settlements worldwide are confronting: When does retreating rather than rebuilding become the only rational choice?

Ellicott City in the early 20th century. (Library of Congress)

On a dreary morning in March, I meet Jim Caldwell, who was then Howard County’s director of community sustainability, at Jax Edwin—a men’s boutique, coffeeshop, and barbershop all loaded into a three-story building on Main Street. He starts our conversation the same way he starts all his flood presentations, with the three Ellicott brothers: Joseph, Andrew, and John.

“They settled here,” he says, pointing to a map of the Tiber-Hudson watershed, “because they needed the water.”

The town sits at the bottom of a steep valley, where four river branches—Tiber, Hudson, Autumn Hill, and New Cut—feed into the larger Patapsco River. In 1772, this was the right spot to harness the power of water and build a mill, so the enterprising Ellicotts constructed roads and houses right on top of the streams. If you look at a map, the waterways snake back and forth underneath Main Street.

Ellicott City is built atop a network of streams that once provided power for the town’s mills. (Map tiles via Wikimedia Maps, CC BY-SA 4.0. David H. Montgomery/CityLab)

As a result, the town has always been at the mercy of the river. The deadliest incident was in July 1868, when a 20-foot wall of water was said to have crashed into the heart of Ellicott City. Vivid illustrations of rescues made via boats and of houses getting washed away accompanied a dramatic description of the disaster in Harper’s Weekly.Between 40 and 50 people were killed, and the entire flour mill industry was destroyed.

But the first “top-down” flood, in which floodwaters rushed in from the top of the watershed rather than rose from the streambeds, came in 1952. That’s the same kind that hit Ellicott City in both 2016 and 2018. “You get a little bit of a snowball up here,” Caldwell says, pointing to the top of Main Street, which is about 140 feet higher than the lower end. “By the time it gets down, it’s a huge snowball because everything is running down the hill to get to the Patapsco.”

That geography makes avoiding flooding entirely all but impossible. “Ellicott City was completely built in the 100-year floodplain,” says Caldwell. “If this was an open stream today and somebody said, ‘I want to build a city here,’ they couldn’t do it.”

Historically, after every major flood—they came about every 10 years, as in 1901, 1917, and 1923—the town rebuilt. Twin blows from hurricanes Agnes (in 1972) and Eloise (1975) convinced many residents and shopkeepers to move away, but new ones moved in, and Ellicott City was reborn as a tourist town.

As a result, the town has always been at the mercy of the river. The deadliest incident was in July 1868, when a 20-foot wall of water was said to have crashed into the heart of Ellicott City. Vivid illustrations of rescues made via boats and of houses getting washed away accompanied a dramatic description of the disaster in Harper’s Weekly.Between 40 and 50 people were killed, and the entire flour mill industry was destroyed.

But the first “top-down” flood, in which floodwaters rushed in from the top of the watershed rather than rose from the streambeds, came in 1952. That’s the same kind that hit Ellicott City in both 2016 and 2018. “You get a little bit of a snowball up here,” Caldwell says, pointing to the top of Main Street, which is about 140 feet higher than the lower end. “By the time it gets down, it’s a huge snowball because everything is running down the hill to get to the Patapsco.”

That geography makes avoiding flooding entirely all but impossible. “Ellicott City was completely built in the 100-year floodplain,” says Caldwell. “If this was an open stream today and somebody said, ‘I want to build a city here,’ they couldn’t do it.”

Historically, after every major flood—they came about every 10 years, as in 1901, 1917, and 1923—the town rebuilt. Twin blows from hurricanes Agnes (in 1972) and Eloise (1975) convinced many residents and shopkeepers to move away, but new ones moved in, and Ellicott City was reborn as a tourist town.

Flood City, USA: Ellicott City is no stranger to inundation. In 1972, Hurricane Agnes left hundreds homeless.  (Howard County Historical Society)

It enjoys a strikingly beautiful setting—a postcard-pretty 19th-century Main Street of tidy homes and shops built of local granite, threaded amid a rugged woody landscape just miles from Baltimore. The historic district, only accessible via a handful of narrow winding roads, has been spared new development, and its economy is increasingly based on serving the needs of visitors, with ghost tours, a railroad museum, and an aggressively whimsical stock of antique and trinket shops.

Read the full City Lab article . . .