On May 31, 1889, the South Fork Dam on Pennsylvania's Little Conemaugh River broke
sending 16 million tons of water rushing towards Johnstown, PA. More than 2,200
people died when the wave of destruction shattered their homes and businesses.
Photo courtesy of the City of Boston, MA.
After a May 1889 storm dumped nearly 10 inches of rain on Pennsylvania, the South Fork Dam on the state's Little Conemaugh River could no longer hold the rain-swollen waters of Lake Conemaugh. Around 3:00 p.m., on May 31, the earthen barrier failed and sent a massive wave of destruction through the villages of the Conemaugh Valley, including Johnstown, PA. When the water subsided, 2,208 people were dead, making the "Johnstown Flood" the deadliest disaster in U.S. history until the 1900 Galveston Hurricane.
Pennsylvania began construction of the South Fork Dam on the Little Conemaugh River in the 1840s in order to supply additional water volume during droughts to the Pennsylvania Mainline Canal stretching from Philadelphia to Pittsburgh, PA. After the Pennsylvania Mainline Canal went out of business in 1854, and canal traffic between Johnstown and Blairsville. PA, ended in 1863. No agency maintained the dam and damage from a partial failure in 1862 went unrepaired for years. Removal of flood control pipes in 1875 weakened the damaged dam even further and limited flood control options. In 1879, Benjamin Ruff purchased Lake Conemaugh and the surrounding property for the wealthy clientele of his South Fork Hunting and Fishing Club. Included in the purchase was the distressed South Fork Dam. Ruff hastily repaired and "improved" the neglected dam. In doing so, he compromised the dam's integrity by lowering its height to construct a road to his clubhouse and blocking the dam's spillways with screens to prevent Lake Conemaugh's fish from escaping.
In late May 1889, a low pressure system stalled over Pennsylvania, dumping an estimated 6 to 10 inches of rain on the Conemaugh River Valley. On the morning of May 31, Elias Unger—president of the South Fork Fishing and Hunting Club—awoke to discover that Lake Conemaugh's water level was rising rapidly. In the decade since Benjamin Ruff altered the dam, debris had clogged the fish screens installed across its spillways, preventing the release of excess water. Despite the best efforts of Unger and his employees to ease the stress on the dam, they were unable to divert the rising water or clear the dam's spillways. They warned the villages downstream as water began overtopping and eroding the dam by early afternoon. Lake Conemaugh finally breached the dam around 3:00 p.m., sending approximately 3.8 billion gallons of water racing down the valley towards South Fork, Mineral Point, and East Conemaugh. When the flood waters reached Johnstown, 14 miles downstream from the South Fork Dam, the wave surged through the city crushing terrified victims in a torrent of mud, broken trees, shattered homes and furniture, barbed wire, and debris.
That evening, the shocked residents of the Conemaugh Valley began assessing the damage and searching for missing family members and neighbors. The deadly wave left 2,208 people dead and destroyed approximately 1,600 homes. Damage to homes and businesses amounted to about $17 million dollars—more than $450 million in 2019 dollars. Within days, work crews and volunteers repaired the bridges and roads; the Pennsylvania Railroad restored service; and relief workers, supplies, and money from throughout the United States poured into the region. It would take decades for the region to recover from the disaster, during which Johnstown and the surrounding valley towns suffered significant floods, but none would be as severe or deadly as the 1889 disaster. Today, the 1889 Johnstown Flood remains the second deadliest dam failure, eclipsed only by the Banqiao Reservoir Dam failure in Zhumadian City, China, that killed an estimated 171,000 people in August 1975.
You can learn more about the Johnstown Flood, its victims, and the region's recovery using census data and records. For example:
An 1889 bird's-eye view map of the Conemaugh Valley from Nineveh, PA, to the Western Reservoir (Lake Conemaugh). When the earthen South Fork Dam
at the reservoir failed on May 31, 1889, a wall of water cascaded through the valley destroying everything in its path and killing 2,208 people.
The Johnstown Flood remained the nation's deadliest national disaster until surpassed by the September 1900 Galveston Hurricane.
Photo Courtesy of the Library of Congress.
Two Johnstown, PA, brothers earned the Medal of Honor during the American Civil War?
While commanding the 1st West Virginia Cavalry, Charles E. Capehart earned the Medal of Honor for capturing a Confederate wagon train retreating from the Battle of Gettysburg on July 4, 1863.
Charles' older brother (and 1st West Virginia Cavalryman) Henry Capehart received the Medal of Honor after saving the life of a drowning soldier in 1864. Capehart led a brigade of George Armstrong Custer's Third Cavalry Division during the Battle of Appomattox Courthouse and the Army of Northern Virginia's surrender on April 9, 1865.
Henry and Charles survived the war and died in 1895 and 1911, respectively. They are buried at Arlington National Cemetery.
Cyrus Guernsey Pringle was born in Charlotte, VT, on May 6, 1838.
As a special agent during the 1880 Census, Pringle explored the forests in New York, Pennsylvania, West Virginia, and the New England states. The Census Bureau published the data he collected in the 1884 Report of the Forests of North America.
Since his death on May 25, 1911, several plants have been named for Pringle, including the Mexican Cobaea pringlei, Pinus pringlei, and Pachycereus pringlei.
The United States commemorates the 1889 Johnstown Flood through the annual May 31 observance of National Dam Safety Awareness Day.
The awareness day promotes the inspection, maintenance, and safety of private and public dams. It also highlights steps dam owners can take to prevent catastrophic failures and lessen the impact of potential failures.
In 2018, the U.S. Army Corps of Engineers' National Inventory of Dams reported that there were more than 91,000 dams in the United States. In addition to providing reservoirs for drinking water, irrigation, recreation, and land reclamation, 7 percent of these dams—like the Hartwell Dam (above) on South Carolina's Savannah River—provide hydroelectric power.
In 2012, the economic census reported that there were 405 hydroelectric power generating establishments (NAICS 221111) in the United States that employed 3,464 and generated revenue of $2.45 billion. New York led the nation with 52 establishments, followed by Wisconsin (35) and California (31)