How Weakened Infrastructure Led To The Johnstown Flood

Jun 12, 2015

On May 31, 1889 the South Fork dam in Cambria County failed, sending a flood wave through Johnstown that killed 2,209 people.

After a month of rain, a particularly heavy storm hit Johnstown on May 30, filling the streets with a couple feet of water by noon the next day. Flooding was nothing new, though: The city was built on a floodplain, at the base of mountains denuded by industry, at the confluence of three rivers. So people moved to their upper floors to wait.

Victor Heiser told author David McCullough his father sent him to let the horses out of the barn.

"I still saw my father and my mother standing in the back window, agonized, thinking that I was the one that was in trouble," Heiser said. "And the next second, it seemed to me just a minute, maybe it wasn’t a minute, it struck our house. It was just gone, like that; crushed." 

Richard Burkert, president and CEO of the Johnstown Area Heritage Association (JAHA), sits in a corner of the Johnstown Flood Museum and tries to describe the horror. He's surrounded by photos of its aftermath: surreal images of houses skewered by trees and passenger cars draped over houses. 

"A wall of water 37 feet high hit the downtown part of Johnstown and was pushing ahead of it trees, houses, 80-ton locomotive," Burkert said. "People had no idea what had happened. Some of them assumed this was the apocalypse."

Burkert said the events of that day remain relevant. 

"The flood peels off the veneer of Victorian society and really reveals its true form — a lot of exploitation, of people, of the environment. And a lot of heedlessness," he said. 

Johnstown prospered from that trade of people and environment for industry: By the end of the Civil War, they were the country’s largest producer of iron and a crucial port city along the Pennsylvania Main Line, a rail-and-canal system that moved goods from east to west. But the canal connecting Johnstown to Pittsburgh tended to run dry in the summer, said Burkert.

“They decided to build this big reservoir up in the mountains above Johnstown to hold water for dry spells,” he said.

It took the Commonwealth 18 years to complete the project, just in time for the railroad to put the Main Line out of business in 1854. The reservoir was quickly abandoned.

The remains of the reservoir lie about 10 miles northeast of Johnstown by car in the present-day community of St. Michael. It used to be a getaway for some of Pittsburgh’s wealthiest businessmen, said Megan O’Malley, chief of interpretation at the site.

“An entrepreneur from Pittsburgh saw this opportunity to develop this site and bought the dam," she said. "And with some people in Pittsburgh, established the South Fork Fishing and Hunting Club.”

The club lowered the dam to create a sweeping road wide enough for two carriages. They stocked the reservoir, now Lake Conemaugh, with expensive fish and installed a screen across the dam’s spillway to keep the fish from escaping, said O’Malley.

“The club really was up here for recreation and enjoyment and the maintenance of the dam was really not in the forefront of their minds,” she said. “And I think we could argue that that’s pretty commonplace. No one coming to recreate at a resort is really concerned about the HVAC system in the building.”

The changes made by the club weakened the South Fork dam’s already questionable stability; it had failed once before in 1862.  

When the surveyors for the Pennsylvania Main Line looked for a site to build the reservoir, the bowl-shaped valley north of Johnstown seemed ideal. O’Malley walked to the bottom of the former lake bed. Before the dam gave way, the spot was under 65 feet of water. O’Malley said firsthand accounts describe the dam as “melting away” as that water overflowed and raced down the mountain.

“It was a massive amount of water," she said. "Estimates are about 30 million tons. It’s like Niagara Falls spontaneously occurring.”

It destroyed 30 homes in South Fork and left nothing standing in Mineral Point; East Conemaugh was leveled. When the water hit Woodvale’s Gaultier Wire Works, boilers exploded and mountains of barbed wire were swept into the wave.

The devastation of the events in Johnstown informed legislative action called the Flood Control Act, building projects to decrease the likelihood of flooding. But Werner Loehlein, chief of the water management section for the Pittsburgh District of the U.S. Army Corps of Engineers, points out the folly of the act’s name.

“We really don’t control floods," he said. "Mother Nature’s in the driver’s seat.”

Much of the United States’ infrastructure is aging out. While the Corps could build ever-bigger projects to protect against extreme events, it’s up to lawmakers to find the balance between cost and perceived risk, said Loehlein.

“We provide the engineering solutions and you make the value choice," he said. "Because ultimately decisions are value choices, they’re not technical decisions.”

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