Johnstown, Pennsylvania is located 60 miles east of Pittsburgh in a valley near the Little Conemaugh, Allegheny and Stony Creek Rivers. Johnstown is located on a floodplain that has been subjected to many disasters. Because this area had been the location to many floods, a dam was built on the Little Conemaugh river in 1840 which is 14 miles upstream from Johnstown (4). Whenever there were rains and mountain run-off, the streets of Johnstown tended to flood, sometimes a couple of feet, sometimes a few inches. Deforestation, caused by extensive settlement of the area, contributed to runoff problems beginning after the Civil War.

Image 1: Lake Conemaugh held back by the South Fork Dam before the flood.
This dam was considered the largest earth dam in the United States at the time, more than 70 feet high and 900 feet across (see image 1). Underneath the dam was a huge stone discharge culvert in which sat five cast-iron pipes, each two feet in diameter. The purpose of these pipes was to allow water to leave the reservoir any time the water level became too high. This created the largest man made lake at the time called Lake Conemaugh. On June 10, 1862, the dam gave way after a huge storm but there was little downstream damage because the reservoir was only half full and a watchman at the dam opened the five valves, releasing the pressure on the dam.
The dam was a part of a canal system that was later no longer used because of the development of the railroad to transport goods. Maintenance of the dam was neglected. The lake was sold to the South Fork Fishing and Hunting Club who said they'd repair the dam so some of the wealthiest men in America--Henry Clay Frick, Andrew Mellon, Andrew Carnegie--could have a beautiful place to summer (7). They decided that this would be the perfect spot if the dam could be repaired and the lake could be made even larger than it already was.

The Disaster

In 1889, Johnstown was home to 30,000 people. On May 31, the town residents were unaware of the danger that the record rainfall from the previous days had caused. The people of Johnstown had grown accustomed to the usual flooding every Spring but the ten inches of rainfall in 24 hours was more than the dam could handle. Parts of Johnstown were already underwater as a spillway in the dam got clogged with debris that could not be dislodged. At 3:15 pm, the dam collapsed. The only warning residents of Johnstown had was a loud roar. Twenty million tons of water from Lake Conemaugh rushed at the town at 40 miles per hour at about 70 feet high (4). Anything in the path of the flowing water was taken out including people, dead and alive, and their homes as they were crushed and swept away. Thirty-three train engines were pulled into the water and whirlpools brought down may tall buildings. It took no more than ten minutes for the flood to rush through the town. More than 2,200 people were killed in the flood, almost 10 percent of the city's and surrounding area's population. The clean up took years, with some bodies found months later (see image 2).

Image 2: Residents survey the damage.
For more than a hundred years, the Johnstown Flood was the worst single-day civilian loss of life in U.S. history (6). Little was done to address the fact that another flood of similar magnitude could occur, partially because so little was known about flood protection and prevention at the time. In 1890 the city of Johnstown launched its own flood control efforts that included passing laws prohibiting dumping that would clog the river and establishing minimum channel widths. The Johnstown also built floodwalls in certain locations. Pennsylvania's governor, James Beaver, created the Pennsylvania Relief Committee for cleanup and restoration, while the state militia kept things in order. With thousands of men working, the Pennsylvania Railroad rebuilt 20 miles of track in two weeks. Within five years the city had been rebuilt, but residents continued to live under the constant threat of flooding when heavy rains occurred, floods which destroyed the town again in 1936 and 1977 (5).
Image 3: The floodwalls that were built after the 1936 flood.

What improvements were made since the 1889 flood?

After the flood of 1936, Johnstown residents wrote President Roosevelt 15,000 letters asking the federal government to assist them by providing federal aid to dredge the rivers and oversee other flood control projects. The Flood Control Act of June 22, 1936 followed the1936 flood. This legislation authorized the federal government to construct river walls, dams and other flood control systems throughout the nation’s high risk flood zones (6). Local officials undertook several projects to prevent future disasters. The projects included the construction of two floodwalls on the Stony Creek and Conemaugh rivers and channel improvements along 8.8 miles of the Conemaugh, Little Conemaugh, and Stony Creek rivers (See image 3)(5). Eventually, the river was deepened and channelized behind concrete walls but another storm in 1977 caused another flood, causing 85 deaths and $200 million in property damage (7). Johnstown will continue to flood out from time to time because of its location on the nearly flat flood plain at the meeting of the two rivers whose watersheds drain mountains.

The 1991 Congress authorized and directed the Pittsburgh District of the U.S. Army Corps of Engineers to undertake a major rehabilitation of the existing Johnstown, Pennsylvania Local Flood Protection Project. The rehabilitation work included repair or replacement of 53 existing wall sections, portions of the slope and channel bottom concrete paving. The maintenance is scheduled to be completed in 2008 or 2009.

Johnstown Flood Pennsylvania 1889
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Johnsonville before the flood.
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Johnsonville after the flood.
The flood was so strong it ripped up railroad ties and carried them away. There was a 75 foot railroad viaduct that acted as a temporary dam. The debris was too great and it too collapsed, even more violently than they collapse of the first collapse. Behind the railroad viaduct was the second town, Mineral Point, that was hit. John Hess, a train engineer, tried to warn the residents of Mineral Point by tying don his train whistle and racing the wave on a remaining track, but was unsuccessful and many still died.


(1) Weatherwise; Nov/Dec2007, Vol. 60 Issue 6, p42-49, 8p, 6 color, 7 bw Illustration: p43
(2) Weatherwise; Nov/Dec2007, Vol. 60 Issue 6, p42-49, 8p, 6 color, 7 bw Illustration: p42
(3) Parks & Recreation; Jun2008, Vol. 43 Issue 6, p80-80, 1p, 1 bw
(4) Weatherwise; Nov/Dec2007, Vol. 60 Issue 6, p42-49, 8p, 6 color, 7 bw
(5) Library Journal; 10/15/2003, Vol. 128 Issue 17, p110-110, 1/7p
(6) National Journal; 3/9/2002, Vol. 34 Issue 10, p712, 2p, 2 bw
(7) Adam Issenberg (2004, November 17). After the Flood; In 1889, a wall of water made Johnstown, Pa., synonymous with disaster. It still bears the marks :[FINAL Edition]. The Washington Post,p. C.02. Retrieved December 1, 2008, from ProQuest National Newspapers Core database. (Document ID: 737254561).