The monumental dams of the American West were once hailed as modern temples. They represented the ultimate conquest of nature, giving engineers confidence to subdue great rivers worldwide. Yet, the quest for engineering perfection masked a dangerous political and bureaucratic hubris. As the best dam sites disappeared, engineers were forced to build on inferior, dangerous ground. This relentless ambition led directly to catastrophe.
Cost of the ill-fated Teton Dam
The Teton Dam disaster in Idaho stands as the most prominent symbol of this deadly engineering hubris. This $85 million rockfill structure was built in a great hurry despite overwhelming geologic warnings. The ultimate failure of Teton Dam released the second-largest flood in North America since the last Ice Age.
Potato yield per acre during the 1961 drought
The Project No One Needed
The Teton Dam, authorized in Idaho, was politically unstoppable. It was intended primarily to provide supplemental water to irrigators in Fremont and Madison counties. The rationale for the dam rested on flimsy economic and natural grounds. One primary booster, Willis Walker, argued that crops were failing for lack of water. However, a graduate student later discovered that the yield of potatoes in the worst drought year, 1961, was 212 hundredweight per acre, higher than the average in preceding normal years.
The Snake River Aquifer, lying directly beneath the Teton River, already provided copious water storage. Pumping groundwater was a solution, but local farmers wanted federal taxpayers to bear 90 percent of the cost. Mormons in the region, known for conservative values, fiercely supported the subsidized project. They championed “big water projects” while opposing “nickel-and-dime welfare”.
Political support secured fast authorization and generous appropriations. Senator Frank Church, a powerful liberal, became a dedicated proponent. He later castigated the Bureau of Reclamation (BoR) for “stale engineering ideas,” but failed to apologize for the political pork barrel that funded the dam.
Ignoring the Geologic Time Bomb
The BoR’s decision to build Teton Dam meant ignoring foundational geologic defects. The area was underlain by porous, fractured volcanic rock. The damsite itself was located in a high seismic risk area, designated Zone 3. In late 1972, geologists from the U.S. Geologic Survey (USGS) raised concerns about the dam’s fundamental safety.
One geologist, Dave Schleicher, wrote an internal draft memorandum expressing amazement that the Bureau seemed oblivious to the risks. He noted that five earthquakes had been detected within 30 miles (48 km) of the site in the past five years. Schleicher warned that a failure due to seismic activity or other causes would make the 1962 flood look like “small potatoes”. This stark warning was aggressively toned down and delayed before reaching BoR superiors. The revised letter, dated April 3, 1973, carried the “quality of weak tea”.
The Bureau’s internal testing provided ample evidence of dangerous instability. In 1970, test drilling showed three deep holes in the critical right canyon wall refused to fill. These holes, including one only 250 feet (76 m) from the proposed dam embankment, absorbed up to 440 gallons (1,665 L) of water per minute. A regional geologist, Clifford Okeson, concluded that some reservoir leakage was inevitable.
Despite the known risks, the Bureau’s head of dam design, Harold Arthur, later insisted the site was deemed suitable after test grouting. Crucially, the test grouting program was only conducted on the easily accessible south abutment. No grouting was performed on the north side, the right abutment, where the serious leakage problems were later found. This negligence was confirmed in 1974 when contractors found “unusually large” fissures in the rock of the right canyon wall during excavation.
The Race to Fill the Reservoir
The dam was structurally finished in October 1975, and the river flow was interrupted for the first time. Teton Dam was built near the Teton Mountains, where a huge snowpack was melting quickly in the spring of 1976. The BoR had a simple, time-honored rule for earthfill dams: the reservoir filling rate should be kept below one foot (0.3 m) per day. This rule allowed engineers to deal with developing problems.
Robbie Robison, the young project engineer, formally requested permission for a two-foot-per-day (0.6 m per day) filling rate, ostensibly to test the grouting program’s effectiveness. Harold Arthur, the chief of design, readily acceded to the request on March 23, 1976. However, this entire procedure was a meaningless charade. The main outlet works, essential for controlled drawdown in an emergency, were not yet finished. The Teton River, engorged by a snowpack half again as deep as normal, would peak at several thousand cubic feet per second. The reservoir was rising much faster than the two-foot limit.
Bureau geologist Gordon Haskett disclosed in a memo that the adjacent groundwater table was rising at a rate over 1,000 times that calculated for predicted movement. Arthur received this memo on April 13, weeks after approving the fast fill rate, and filed it away. Arthur later confessed the Bureau might not have believed a device detecting massive seepage, given their “perfect record up to then”. The agency’s immense confidence proved fatal.
The Catastrophic Failure
On Thursday, June 3, 1976, equipment operators noticed the first small leak pouring out of the right canyon wall, a third of a mile below the dam. The water was clear, flowing at about 60 gallons (227 L) a minute. By nine o’clock that night, it was too dark to monitor.
Saturday, June 5, around 7:30 AM, a muddy creek appeared, indicating that water was piping inside the dam’s core. Piping is a signal that water is excavating channels within the structure, leading to catastrophic failure. By 9:30 AM, a sizable torrent was washing away the dam’s embankment. Robbie Robison quickly ordered the evacuation of twelve thousand people.
Bulldozers attempted to plug the hole, but the torrent swept away all material. A terrifying whirlpool developed in the reservoir a few yards from the dam face, confirming water was sluicing directly through the core. At 11:55 AM, the dam crest abruptly fell into the reservoir. Two minutes later, a titanic flood was unleashed down the Teton River Canyon.
The devastation was immediate. Six miles (10 km) from the dam, two towns, Wilford and Teton, sat on the flat Snake River Plain. The leading wave arrived in just 25 minutes, peaking at 20 feet (6 m) high. The flood snapped huge cottonwoods and tore houses off their foundations. In Rexburg, logs smashed into a bulk gasoline storage tank, which exploded. Flaming gasoline then poured into the town, setting houses on fire. The local newspaper, the Idaho Statesman, ran excellent reporting on the disaster.
The immediate disaster caused 11 deaths, though a similar dam collapse, the St. Francis Dam, killed more people than the San Francisco earthquake.
A Pattern of Ignoring Faults
Teton Dam was not the first instance of a potentially catastrophic failure due to the BoR’s overreach. In September 1965, the Fontenelle Dam on the Green River in Wyoming, built on a “lousy” site for the Seedskadie Project, sprang a big leak. The leak quickly turned into a “waterspout,” signaling piping within the dam. The chief engineer, Barney Bellport, ordered both outlet works opened full-bore to save the structure. Bellport later recalled the unbearable tension, comparing it to nearly hitting an oncoming car at high speed.
Fontenelle Dam hemorrhaged muddy water, but miraculously held. Engineers later determined that trona (sodium carbonate) in the local soil accelerated the setting of the grout curtain, leaving fissures for water to penetrate. Bellport quickly deflected blame for Teton Dam, insisting it was an “act of God or human error” that should not reflect on the agency’s record.
The Bureau was routinely building dams on sites rejected decades earlier because demand had outstripped the supply of good locations. Critics warned that the failure of one large, strategically placed dam, such as Glen Canyon, could cause a domino effect, taking out other dams and ruining the Southwest economy.
Despite the Teton tragedy, some locals still called for the dam to be rebuilt. Even politicians like Colorado Governor Richard Lamm, who championed the environmentally disastrous Narrows Dam, admitted that Washington offered an economic impetus too great to turn down. This political calculation ensured that the “grand adventure of playing God with our waters” would continue, driven by an unwillingness to admit the cost of conquering the desert. The massive engineering triumphs often justified the means, regardless of the consequences.
In the arid West, the monuments built to ensure survival often became monuments to the fragility of human ambition, demonstrating that physics ultimately supersedes politics.