That Dam Planning Failure

June 5th of this year marked the 37th anniversary of the Teton Dam collapse. The eastern Idaho Dam broke in the summer of 1976, just after it had been filled for the very first time.

Teton Dam failureThe failure caused flooding that washed away many of the surrounding homes and businesses and it killed at least 11 people in the area. While the majority of the deaths occurred in small agricultural towns closest to the dam, the Rexburg area further downstream, with over 10,000 people, was hit with a massive amount of destruction. The collapse of the dam caused millions of dollars of property damage, produced over 200 landslides, killed thousands of livestock, hurt the river’s ecology, and wiped out entire fertile agriculture fields. Over $320 million was paid out to disaster victims by the federal government over the next decade.

So, what caused this massive disaster to happen? Who is responsible for the lives lost and the thousands of people affected? More importantly, with better planning, could this disaster have been prevented?

The construction of the dam started in 1972, and it was built by the Bureau of Reclamation, a federal agency. When the dam was proposed to congress in the mid 1960’s, a bill approving construction was quickly passed without opposition. The dam would control spring runoff and provide a more reliable/stable supply of water in the summer, and it would also be a source of electricity. The only environmental impact statement issued before the dam was built did not even mention the possibility of a collapse. Staying optimistic is a good plan for some people I guess, after all, you don’t want to scare people about things that might happen…

The primary contractor for the dam that was chosen turned out to be Boise’s own Morrison-Knudsen. This was an exciting project for a company located in Idaho- and just think of all the jobs it would provide to the local economy too! It made sense to everyone in the local community to support something like this, especially when it was getting largely funded and approved by the federal government. Nobody needed to worry about all of the small details or safety risks, surely somebody was going to make sure this thing was done right. After all, the project was being done for the citizens, wasn’t it? The government planning this thing was going to look after the population in the area… right?

Location of teton damWell, it turns out that the dam was built on a site that was composed of mostly rhyolite and basalt, volcanic material, which is considered unsuitable for dam construction because of high permeability. This wasn’t something they found out after the fact either. Tests done before the construction showed that the site was unstable and highly fissured. The Bureau of Reclamation had a plan to seal the fissures by injecting grout into them under high pressure. I don’t know if they had ever tried it before, but one of the most rural areas of the country sure makes a nice place to try it out.

After the Bureau had dumped several million dollars into the project they found out the fissures were a little bigger than they anticipated- well, actually they were more like caves, too big to be grouted as planned. Everybody figured too much was already invested into this thing though, so no going back, they continued construction.

While the dam wasn’t even around long enough to be affected by it, the lack of safety concerns is evident by other risks as well, such as the fact that the region is prone to small earthquakes. A survey done during the construction showed that five earthquakes had occurred within 30 miles of the site in the last few years. This fact didn’t seem to matter much to anyone either though, at least not enough to stop construction.

So, why wasn’t the Bureau more careful? Why did they rush the project when there were obvious safely concerns? They later claimed they followed all of the established “strict criteria” in building the dam, so they never took the blame or stated that they knew it was unsafe. It is important to note that a new Safety of Dams Program was established in response to the Teton Dam failure though, apparently with stricter criteria to follow (or ignore).

It’s obvious that safety was not a priority, and no matter what the plan was going to be, the project was going to get done. So, to answer my own question posed earlier, of course this could have been prevented. Just take self-interest, money, greed, and politics out of the equation and the dam never would have been built.

The only plan I see that anybody followed was to complete the project at all costs, safety be dammed.

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One thought on “That Dam Planning Failure

  1. Great article. I think this shows the disasters that can happen when the government continues with a fail project simply because of sunk costs.

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