1889 South Fork Dam Flooding of Johnstown, PA

Ruins: (Satellite)

NPS Visitor Center: (Satellite, 2490 photos)

USACE, Pittsburgh District posted two images with the comment:

Today [May 31] marks a somber anniversary — the 1889 South Fork Dam disaster in Johnstown, Pennsylvania. As we observe National Dam Safety Awareness Day, let's reflect on the lessons from the past to safeguard our future.

The South Fork Dam, originally built in the 1840s for the Pennsylvania Main Line Canal, experienced a catastrophic failure on May 31, 1889, releasing approximately 3,600,000,000 gallons of water. This tragic event resulted in over 2,200 lives lost and immense property damage, highlighting the critical need for diligent maintenance and safety protocols in dam engineering.

Through the years, from its initial construction to its eventual failure, the dam's history can teach the nation about the dangers of neglect and the importance of robust infrastructure. In 1879, changes made by the South Fork Fishing and Hunting Club compromised the dam's integrity, directly contributing to the disaster. This included removing crucial discharge pipes and lowering the dam's height to accommodate carriages, while also failing to maintain essential spillways.

Today, the U.S. Army Corps of Engineers Pittsburgh District is committed to preventing such tragedies. Our dam safety program follows strict safety regulations and conduct regular inspections to ensure the structural integrity of our nation’s dams.

📽️ Explore more about the South Fork Dam and its history through photos and timelines from our friends at the HISTORY:  https://www.youtube.com/watch?v=Zj2v5Akm1Bg ["It was the biggest man-made lake in the world." This video shows a masonry dam breaking, but it was an earth dam that was overtopped.]

Let’s honor the memory of those lost in Johnstown by committing to excellence in dam safety and infrastructure management. Together, we can protect communities and lives.

U.S. Army Corps of Engineers Pittsburgh District: Photos sourced from the National Park Service

Pam Walaski: Important to remember who made the changes to the dam that led to its eventual collapse. The Club was a playground for the Pittsburgh elite - Andrew Carnegie and Henry Clay Frick to name a few. David McCullogh’s book is an excellent read in this tragedy.

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nps
"The remains of the South Fork Dam from the Visitor Center area."
The dam had already failed in 1847 and 1862.

PowerLibrary via search, Educational use permitted

As the dam was built and maintained by the Pennsylvania Main Line Canal and the Pennsylvania Railroad.

nps

1. The dam was watertight due to puddled earth or being packed down. 

2. The dam had a spillway that was unobstructed, allowing for runoff. 

3. There was a control tower in the middle of the dam. 

4. There were discharge pipes in place at the base of the dam, allowing the water level to be controlled. 

As damaged by private owners.

nps

1. The earth is not puddled and there were several leaks in the dam.

2. The spillway is obstructed with a bridge and fish screen.

3. The control tower burned down and was not replaced. 

4. The discharge pipes were removed and the lake level was filled up to 70 feet in places. 

5. To widen the road across the dam, it was lowered.

6. In 1862 the dam broke, resulting in a sag in the middle where repairs had been made.

This 13:30 video also shows a masonry dam bursting. But the narration calls it an earthwork dam. "When finished, it was the largest earth-work dam in the world." 284m (931') long and 22m (72') high. This video skipped the private ownership that removed the outlet works. It does a good job of describing the flood damage. The $17m damages is about $500m in today's money.