Dive Brief:

• The drought-induced drop in Lake Mead’s water level has caused the nameplate capacity of the 17-unit hydroelectric Hoover Dam facility on the Nevada-Arizona border to be derated from 2,074 megawatts to 1,592 megawatts and it is expected to be reduced again later this year, threatening the peak demand electricity supply for Las Vegas, Los Angeles and other Southwest cities.
• The Colorado River Basin is in its fourteenth year of drought, causing a one and one-half to two foot drop per month at Lake Mead, leaving the June water level at 1,083 feet, or 40% of capacity, and affirming the recent Bureau of Reclamation projection that Hoover Dam’s electricity production will fall to 1,120 megawatts by May 2016.
• It was previously necessary for Lake Mead to have at least a 1,050 foot water level for Hoover Dam to generate but new, higher-efficiency turbines and controls that make the dam "more efficient than any time in its history” will soon make it possible to revise the minimum water level to 950 feet.

Dive Insight:

Hoover Dam’s electricity is sold at a wholesale rate of $0.02018 cents per kilowatt-hour to the Metropolitan Water District of Southern California, the state of Nevada, the state of Arizona, the city of Los Angeles, Southern California Edison Co. and 10 cities downstream.

The plant that once produced more than 4 billion kilowatt-hours per year fell to 3.7 billion kilowatt-hours in 2009 and has been falling yearly ever since.

The iconic Hoover Dam went into service in 1936 to manage the Colorado River water supply for cities of the Southwest and to irrigate the region’s farmland, and the hydroelectric power revenue, which makes the Dam a self-sustaining enterprise, is a byproduct of those services.

The drought has affected federal dams and their reservoirs across the Southwest, including the Glen Canyon Dam and Lake Powell in northern Arizona which, for the first time, reduced the amount of water released to Lake Mead, from 8.23 million acre-feet to 7.48 million acre-feet, further hampering Hoover Dam's power production.