Hoover Dam was built in the 1930s during the Great Depression. It is famous for taming the wild Colorado River, providing the power that electrified the American Southwest, and for creating Lake Mead, the largest man-made reservoir in the United States. The dam is as tall as a 60-story building and was the world’s highest dam when it was built. And now, it has real problems.
At some point over the next year, the surface of Lake Mead will drop below its critical threshold of 1,035 feet above sea level. This is the point at which the hydropower generating capacity of Hoover Dam has to be cut by 70%. Twelve of the dam’s 17 turbines are not designed to operate in the low-water conditions that would be present with Lake Mead below that level.
The looming crisis is a result of record-low winter runoff from the Rocky Mountain snowpack, climate-change-driven aridity, chronic over-allocation of water rights on the Colorado River, and massive agricultural demand.
The two major reservoirs filled by the Colorado – Lake Mead and Lake Powell – both have water-level elevation values that trigger negative outcomes when they are too low, and both are nearing these circumstances.
The Bureau of Reclamation, the federal agency that manages the dams, is going to install three new wide-head turbines at Hoover Dam that will be able to generate power down to elevation 950 feet. This will result in a power cut of 58% instead of 70%. Better, but no panacea.
The warming climate is reducing water availability in the Colorado River basin, and it spells major trouble for the millions of people who depend on the river for water and power.
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References:
Hoover Dam Approaches a Hydropower Cliff
