Johnstown Flood - The Great Flood of 1889

The Great Flood of 1889

On May 28, 1889, a storm formed over Nebraska and Kansas, moving east. When the storm struck the Johnstown-South Fork area two days later, it was the worst downpour that had ever been recorded in that part of the country. The U.S. Army Signal Corps estimated that 6 to 10 inches (150 to 250 mm) of rain fell in 24 hours over the entire region. During the night, small creeks became roaring torrents, ripping out trees and debris. Telegraph lines were downed and rail lines were washed away. Before daybreak, the Conemaugh River that ran through Johnstown was about to overwhelm its banks.

On the morning of May 31, 1889, in a farmhouse on a hill just above the South Fork Dam, Elias Unger, then president of the South Fork Fishing and Hunting Club, awoke to the sight of Lake Conemaugh swollen after a night-long heavy rainfall. Unger ran outside in the still-pouring rain to assess the situation and saw that the water was nearly cresting the dam. He quickly assembled a group of men to save the face of the dam by trying to unclog the spillway; it was blocked by the broken fish trap and debris caused by the swollen waterline. Other men tried digging another spillway at the other end of the dam to relieve the pressure, without success. Most remained on top of the dam, some plowing earth to raise it, while others tried to pile mud and rock on the face to save the eroding wall.

John Parke, an engineer for the South Fork Club, briefly considered cutting through the dam's end, where the pressure would be less, but decided against it. Twice, under orders from Unger, Parke rode on horseback to the nearby town of South Fork to the telegraph office to send warnings to Johnstown explaining the critical nature of the eroding dam. But the warnings were not passed to the authorities in town, as there had been many false alarms in the past of the South Fork Dam not holding against flooding. Unger, Parke, and the rest of the men continued working until exhausted to save the face of the dam; they abandoned their efforts at around 1:30 p.m., fearing that their efforts were futile and the dam was at risk of imminent collapse. Unger ordered all of his men to fall back to high ground on both sides of the dam where they could do nothing but wait. During the day in Johnstown, the situation worsened as water rose to as high as 10 feet (3.0 m) in the streets, trapping some people in their houses.

At around 3:10 p.m., the South Fork Dam collapsed, freeing the 20 million tons of Lake Conemaugh to cascade down the Little Conemaugh River. It took about 40 minutes for the entire lake to drain of the water. The first town to be hit by the flood was the South Fork. The town was on high ground, and most of the people escaped by running up the nearby hills when they saw the dam spill over. Despite 20 to 30 houses being destroyed or washed away, only four people were killed.

On its way downstream toward Johnstown, the crest picked up debris, such as trees, houses, and animals. At the Conemaugh Viaduct, a 78-foot (24 m) high railroad bridge, the flood temporarily was stopped when debris jammed against the stone bridge's arch. But within seven minutes, the viaduct collapsed, allowing the flood to resume its course. Because of this, the surging river gained renewed hydraulic head, resulting in a stronger wave hitting Johnstown than otherwise would have been expected. The small town of Mineral Point, one mile (1.6 km) below the Conemaugh Viaduct, was hit with this renewed force. About 30 families lived on the village's single street. After the flood, only bare rock remained. About 16 people were killed.

In 2009 researchers reported the results of studies showing that the volume of the flood through the narrow valley temporarily equalled the flow of the Mississippi River.

"The deluge released by the dam’s collapse carried more than 12,000 cubic meters of debris-filled water each second. Flow rates in the Mississippi River typically vary between 7,000 and 20,000 cubic meters per second."

The village of East Conemaugh was next to be hit by the flood. One witness on high ground near the town described the water as almost obscured by debris, resembling "a huge hill rolling over and over". From his locomotive, the engineer John Hess heard the rumbling of the approaching flood and, fearing what it meant, he tried to warn people downriver: he tied down the train whistle and raced backward toward East Conemaugh. His warning saved many people who reached high ground, but at least 50 people died, including about 25 passengers stranded on trains in the town. Hess survived despite the flood picking up his locomotive and tossing it aside.

Before hitting the main part of Johnstown, the flood surge hit the Cambria Iron Works at the town of Woodvale, sweeping up railroad cars and barbed wire in its moil. Of Woodvale's 1,100 residents, 314 died in the flood. Boilers exploded when the flood hit the Gautier Wire Works, causing black smoke seen by the Johnstown residents. Miles of its barbed wire became entangled in the debris in the flood waters.

Some 57 minutes after the South Fork Dam collapsed, the flood hit Johnstown. The residents were caught by surprise as the wall of water and debris bore down, traveling at 40 miles per hour (64 km/h) and reaching a height of 60 feet (18 m) in places. Some, realizing the danger, tried to escape by running towards high ground. But most people were hit by the surging floodwater. Many people were crushed by pieces of debris, and others became caught in barbed wire from the wire factory upstream. Those who reached attics, or managed to stay afloat on pieces of floating debris, waited hours for help to arrive.

At Johnstown, the Stone Bridge, which was a substantial arched structure, carried the Pennsylvania Railroad across the Conemaugh River. The debris carried by the flood formed a temporary dam at the bridge, resulting in the flood surge rolling upstream along the Stoney Creek River. Eventually, gravity caused the surge to return to the dam, causing a second wave to hit the city, but from a different direction.

Some people who had been washed downstream became trapped in an inferno as the debris piled up against the Stone Bridge caught fire; at least 80 people died there. The fire at the Stone Bridge burned for three days. After floodwaters receded, the pile of debris at the bridge was seen to cover 30 acres (12 ha), and reached 70 feet (21 m) in height. It took workers three months to remove the mass of debris, largely because it was bound by the steel wire from the ironworks. Dynamite was eventually used to clear it.

Still standing and in use as a railroad bridge, the Stone Bridge is a landmark associated with survival and recovery from the flood. In 2008, it was restored in a project including new lighting as part of commemorative activities related to the flood.