Lake Peigneur: The Drilling Disaster That Swallowed a Lake
In 1980, a drilling mistake turned a shallow Louisiana lake into a 200-foot-deep saltwater crater in a matter of hours
On a quiet Louisiana lake, a routine drilling job turned into a real-life horror movie. Lake Peigneur looked harmless from the shore, flat and familiar, the kind of place fishermen and weekend families knew by heart.
But under the water, Jefferson Island sat on a salt dome with an active Diamond Crystal Salt Company mine stretching deep beneath the lake. At the same time, Texaco had a drilling platform working on the lake surface, right above those salt tunnels. Two separate operations, one sitting above the other, were supposed to coexist. Instead, a tiny hole punched into the mine became the start of a chain reaction nobody could stop.
It only took minutes for the lake to start draining like a bathtub with the plug pulled, and the platform went down first.
What Happened at Lake Peigneur
Lake Peigneur was unremarkable before the disaster. It sat in Iberia Parish, near New Iberia, Louisiana, covering about 1,300 acres of flat coastal land. The water was fresh. Maximum depth: about eleven feet.
Local fishermen used it. A botanical garden called Live Oak Gardens operated on nearby Jefferson Island. Families visited on weekends.
Beneath the lake was something less ordinary. Jefferson Island sits on top of a salt dome, one of 128 documented salt domes in Louisiana and one of five along the coast that rise high enough above the surrounding wetlands to form visible islands.
The Diamond Crystal Salt Company had been mining salt from caverns beneath the lake since 1919. The mine extended to depths of 1,500 feet, with tunnels roughly 100 by 80 feet, supported by pillars of salt left in place to hold up the ceiling.
Separately, Texaco had won a state lease to drill for oil in the same area. Oil frequently collects in the folds of salt dome structures, making them attractive targets. Texaco subcontracted Wilson Brothers Corporation to operate a drilling platform on the lake surface, directly above the salt mining operation.
The two activities, drilling from above and mining from below, were supposed to stay out of each other's way. They didn't.
commons.wikimedia.orgThe drill bit finally punched through the third level at 1,228 feet, and it was only a 14-inch opening at first.
The Lake Peigneur Sinkhole
The drill bit pierced the third level of the salt mine at 1,228 feet. The hole was initially small, just 14 inches across. But fresh lake water poured through it into the mine, and salt dissolves in fresh water. The pillars holding up the mine tunnels began to dissolve. The tunnels collapsed. The hole widened. More water poured in.
The process accelerated faster than anyone expected. The lake began draining into the mine like water down a bathtub drain, except the bathtub was 1,300 acres and the drain was growing by the minute.
A massive whirlpool formed over the sinkhole. The drilling platform was the first thing to go, sucked under within minutes. Then the eleven barges moored nearby, loaded with supplies for the drilling operation. Then a tugboat. Then the trees lining the shore.
Then 65 acres of the island itself, including part of the Live Oak Gardens botanical park and its greenhouse. A brick chimney from a house on Jefferson Island still protrudes from the water today. Everything else went under.
The 55 miners working underground during the collapse were lucky. The mine had enough warning time for evacuation. All 55 made it out through a single shaft, the last man emerging just as water reached that level.
Five Diamond Crystal employees later received awards for heroism during the evacuation. One of them, Randy La Salle, drove his truck through remote tunnels at the 1,500-foot level, searching for anyone left behind.
The Lake Peigneur Disaster: Aftermath
Within three hours, the entire lake was gone. The 1,300-acre, 11-foot-deep freshwater lake had drained into the salt mine, and the mine was flooded up to the surface.
Then the Delcambre Canal reversed. The canal had connected Lake Peigneur to Vermilion Bay and ultimately the Gulf of Mexico. With the lakebed now empty and sitting below sea level, saltwater from the Gulf poured backward through the canal and into the crater.
This created a 150-foot waterfall where the canal met the lakebed, the tallest waterfall in Louisiana's history, which is saying something for a state where the highest natural point is 535 feet above sea level.
The waterfall ran for days as the Gulf refilled the crater. When it was done, Lake Peigneur had been fundamentally transformed. What had been an 11-foot-deep freshwater lake was now a 200-foot-deep saltwater lake, the deepest in Louisiana. The ecosystem was destroyed. Every freshwater species in the lake was gone.
Nine of the eleven sunken barges eventually popped back up to the surface, ejected by pressure equalization in the mine below. The other two, along with the drilling platform, the tugboat, and the 65 acres of land, stayed down.
commons.wikimedia.orgThen the fresh lake water rushed into the mine, dissolving salt pillars that were holding up the tunnels beneath Jefferson Island.
This is the same kind of dark history as Lake Shawnee’s burial-ground curse, where children died on rides.
As the tunnels collapsed and the hole widened, the whole lake began draining fast enough to form a massive whirlpool.
What Caused the Lake Peigneur Disaster?
The Mine Safety and Health Administration released a report in August 1981 that documented the sequence of events but, remarkably, did not assign an official cause. The physical evidence that could have confirmed exactly where the drill penetrated the mine was washed away in the whirlpool.
Engineers from Texaco and Diamond Crystal reconstructed the most likely scenario after the fact. The drilling team had been using coordinate data to position their platform safely away from the mine tunnels. The prevailing theory is that someone used the wrong reference system when plotting the drill location, possibly confusing two different measurement standards or misreading the mine maps. The error placed the drill directly above a mined-out section of the 1,300-foot level.
A 14-inch hole shouldn't drain a lake. But salt dissolves. Once the water got in, the mine itself did the rest, enlarging the opening from the inside as pillar after pillar collapsed.
In 1983, Texaco and Wilson Brothers paid $32 million to Diamond Crystal in an out-of-court settlement. Texaco, Wilson Brothers, and Diamond Crystal collectively paid another $12.8 million to the Live Oak Gardens botanical garden. The mine was permanently closed in December 1986.
The drilling platform was the first to disappear, sucked under within minutes, right as the sinkhole kept growing.
Lake Peigneur Today
Since 1994, AGL Resources has used the salt dome beneath Lake Peigneur as a storage and hub facility for pressurized natural gas. This raised concerns among local residents in 2009, who questioned the safety of storing gas under a lake that had already collapsed once. Nearby drilling operations added to the unease.
The lake itself looks calm now. The water is brackish. The botanical garden was partially rebuilt. The chimney still sticks up from the water near the old island shoreline, a monument to the day the ground opened up and swallowed everything above it.
Visitors to the area can see the lake and the gardens. The whirlpool is long gone. The waterfall is long gone. The mine is flooded and sealed. If you didn't know the history, you'd think it was just another quiet Louisiana lake surrounded by cypress trees and Spanish moss.
But the geology hasn't changed. The salt dome is still there. The Gulf of Mexico is still connected through the canal. And the lesson from 1980, that a 14-inch hole in the wrong place can erase 1,300 acres of landscape in three hours, hasn't expired.
Nobody died at Lake Peigneur. By every reasonable analysis, people should have. Fifty-five miners were underground when the ceiling started coming down. Twelve drillers were on a platform that sank.
Fishermen were on the lake when the whirlpool formed. All of them got out. That's the part of the Lake Peigneur disaster that sounds made up. It isn't.
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