The Lake Peigneur Incident: Cause, Lawsuits, and Legacy

The Lake Peigneur disaster occurred on November 20, 1980, when a Texaco oil-drilling crew accidentally punctured the roof of an active salt mine beneath the shallow Louisiana lake, draining roughly 3.5 billion gallons of water underground in about three hours and swallowing barges, the drilling rig, and some sixty-five acres of surrounding land. No one died. The lake, once ten feet deep and fresh, refilled from the Gulf of Mexico as a 1,300-foot-deep saltwater body, and the companies involved later paid tens of millions of dollars to settle claims that eventually totaled nearly half a billion.¹²

What Happened on November 20, 1980

Lake Peigneur sat atop Jefferson Island, one of five salt domes in Iberia Parish, Louisiana. The Diamond Crystal Salt Company had operated a mine beneath the lake since 1956. Texaco Oil Company held State Lease 124, which covered drilling rights under the lake, and subcontracted Wilson Brothers Corporation to drill an exploratory oil well from a floating platform on the surface.¹

Around 9:00 a.m. that Thursday, the seven-member drill crew noticed their fourteen-inch drill bit was stuck. By 10:00 a.m., as they worked to free it, they heard popping noises from below. At 10:30 a.m. the rig began to tilt, and the crew abandoned the platform.³ The bit had broken through the mine roof at the 1,300-foot level.⁴

Water pouring into the opening dissolved the surrounding salt and rapidly widened the breach. A whirlpool formed on the lake surface. It pulled down eleven barges from a nearby canal, the drilling rig, and large sections of shoreline, including a home whose brick chimney still protrudes from the water today.⁵ The Delcambre Canal, which normally drained the lake southward toward Vermilion Bay, reversed its flow entirely. As it did, saltwater from the Gulf rushed inland, and a 150-foot waterfall briefly formed within the lake as water plunged into the void below.¹

How Everyone Survived

Fifty-five salt mine employees were underground when the breach opened. An electrician heard unusual noises, spotted the first signs of water intrusion, and sounded an alarm. The miners evacuated in groups through a single small elevator, waiting their turn to be lifted hundreds of feet to the surface. Every one of them made it out.³

On the lake, the drilling crew got clear of the tilting rig moments before it was pulled under. Fishermen on the water escaped the growing whirlpool with seconds to spare.¹ Three dogs were the only recorded fatalities.³

What Caused the Breach

The physical cause was simple: the drill bit went through the mine roof. Who miscalculated its position became the heart of the litigation.

Diamond Crystal insisted that Texaco and Wilson Brothers had “incorrectly triangulated the position of their drilling operation,” putting the bit directly over an active section of the mine.¹ Texaco disputed that account. Max Hebert, the company’s public affairs coordinator, stated that “Lake Peigneur well number 20 was drilled in the exact location provided by the Corps of Engineers,” confirmed by registered professional engineers. Texaco also said Diamond Crystal had been notified of the proposed drilling location at least ten months in advance and had raised no objection in a December 1979 reply to the Army Corps of Engineers.⁶ Texaco in turn accused Diamond Crystal of concealing the true extent of its underground operations.

Dr. Charles Grote, director of the Louisiana Geological Survey, contradicted Texaco’s defense, saying the rig site “was not set up where it was supposed to be.”⁶ Attorneys for Wilson Brothers cited their own expert investigations disputing Diamond Crystal’s account.⁴

The Lawsuits and Settlements

Combined claims arising from the disaster reached nearly $500 million. The cases funneled through U.S. District Court in Lafayette before Judge Eugene Davis. A trial was scheduled for July 1983, but the judge continued it to allow settlement talks.⁴

Diamond Crystal had sued Texaco and Wilson Brothers for $260 million over the destruction of its mine. The case settled out of court for $32 million, with Texaco paying 93.75 percent and Wilson Brothers paying 6.25 percent. Texaco’s countersuit against Diamond Crystal was dismissed as part of the deal.⁴

J.L. Bayless and the Live Oak Gardens entities sued all three companies over the destruction of a historic 1870 estate, its tropical gardens, and more than sixty-five acres of lakeside property. They settled for $12.8 million. Texaco paid 70 percent, Diamond Crystal paid 25 percent, and Wilson Brothers paid 5 percent.⁴

Diamond Crystal had also named the State of Louisiana as a defendant, arguing that the state, as landowner and lessor of the drilling site, bore responsibility for safety. After the private settlements were reached, Diamond Crystal dismissed the state from its suit. The state paid nothing but remained a named defendant in ten other pending cases at the time.⁴

Class-action suits brought by miners and other employees who lost their jobs when the mine closed were still outstanding in mid-1983, and the hundreds of displaced workers were not included in the major settlements.¹

How the Lake Changed

Before the breach, Lake Peigneur was a roughly ten-foot-deep freshwater lake. After the mine beneath it collapsed and the reversed Delcambre Canal pulled Gulf saltwater inland to refill the basin, it became a 1,300-foot-deep saltwater lake.¹ Oil rigs, buildings, salt-filled barges, and other equipment remain at the bottom of the flooded mine.² The Joseph Jefferson mansion, built in 1870 on a bluff seventy-five feet above sea level, sank thirty feet from its original elevation during the disaster and later burned. Only its brick chimney still stands in the water.⁷ Salt mining at Jefferson Island never resumed.

Regulatory Legacy

Whether regulators had absorbed the lessons of Lake Peigneur was tested in 2012, when a sinkhole formed at Bayou Corne in Assumption Parish after a salt cavern in the Napoleonville dome collapsed. Lake Peigneur and Bayou Corne are the only two sinkholes to form from Louisiana’s 153 known terrestrial salt domes in the last seventy years, and both were tied to human-influenced cavern failure.⁸ Bayou Corne also showed that lateral collapse along the side of a cavern was as dangerous as the top-down collapse regulators had treated as the primary risk.⁹

Louisiana responded with new legislation. Act 368 empowered state conservation officials to regulate solution mining injection wells and caverns. Act 369 required notification when property is located near a salt dome containing mining or storage caverns. Companies were required to update cross-section maps of their operations every five years, prove financial capacity for sinkhole remediation, and obtain pre-approval for salt dome closure plans. If a sinkhole occurs, the responsible company is liable for environmental damages, property damages, and reimbursement for emotional distress.¹⁰

1
64 Parishes. Lake Peigneur Drilling Accident
2
KLFY. 40th Anniversary of Salt Mine Breach Creating Louisiana’s Deepest Lake
3
SunCam. Lake Peigneur Case Study
4
UPI. Settlement Reached in Jeff Island Accident
5
KATC. It’s Been 44 Years Since a Drilling Incident Created a Sinkhole in Lake Peigneur
6
UPI. Texaco Says Its Oil Rig Was in Right Place
7
Louisiana Life. Seismic Rescue
8
Frontiers in Environmental Science. Sinkholes From Terrestrial Salt Domes in Louisiana
9
Mother Jones. The Sinkhole That Swallowed 11 Barges
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ResearchGate. Lessons Not Learned in LA – Lake Peigneur 1980, Bayou Corne 2012