Receding Lake Mead Poses Challenges to Hoover Dam's Power Output

For more than 77 years, the iconic Hoover Dam has been producing dependable and cheap electricity for millions of customers in the Southwest.

In today's climate, the fact that hydropower is both renewable and carbon-free makes the federal dam and others like it across the West that much more integral to any national policy to control CO2 emissions.

But the water level of Lake Mead behind the dam that straddles Arizona and Nevada has been in a steady decline and is already affecting electricity production at the man-made wonder, which was both the largest concrete structure ever built and the largest hydro plant in the world when it was turned on in 1936.

As a result, each of the power plant's 17 generating units with a nameplate capacity of 2,074 megawatts was derated in June; the current capacity is 1,592 MW and is projected to decline later this year.  So the dam mostly provides power only during periods of peak demand, according to Mark Cook, engineering group supervisor at the Hoover Dam.  "We pretty much shut down at night."

Receding Lake Mead Poses Challenges to Hoover Dam's Power Output