Historic Western Drought Threatens Hoover Dam Hydropower

By Rachel Ramirez, CNN

Standing atop the Hoover Dam today, the millions of tourists who visit each year can get a real sense of the West’s climate crisis: In addition to the extreme heat, the sight of so-called “bathtub rings “that shroud Lake Mead has become a disturbing reminder of where the water level was before the region’s historic drought began.

The changes are “breathtaking to see,” Kristen Averyst, senior climate adviser to Nevada Governor Steve Sisolak, told CNN. “If people don’t think climate change is affecting them here and now, just go to Lake Mead and take a look, because that paints a pretty clear picture of what we’re up against in terms of climate change. “

Stretching across the Colorado River on the Nevada-Arizona border, the massive Hoover Dam forms and retains water from Lake Mead, the nation’s largest man-made reservoir. It can produce about 2,080 megawatts of hydroelectricity — enough power for about 1.3 million Americans each year, according to the National Park Service — for California, Arizona and Nevada as well as Native American tribes.

But drought fueled by climate change and overuse of Colorado River water is pushing Lake Mead lower and threatening the dam’s hydropower generation. The drop in water flow nearly halved the dam’s power-generating capacity — about 1,076 megawatts — in June.

The water elevation in Lake Mead is about 1,040 feet above sea level. At 950 feet, the Hoover Dam will be at its lowest point to be able to generate electricity, according to the US Bureau of Reclamation. Without power from the dam, energy providers in the Southwest will have to turn to fossil fuels to fill the void.

It’s an unprecedented challenge among many officials facing officials from the United States Bureau of Reclamation, which manages Hoover Dam operations, as the West runs out of water.

U.S. Bureau of Reclamation Commissioner Camille Touton pointed out in congressional testimony in June that despite the agency’s continued efforts to conserve water, more needs to be done as climate change exerts a pressure on the Colorado River system.

“The system is at a tipping point,” Touton said in its statement. “No amount of funding can completely offset the severe rainfall deficits experienced this year in the Western United States. We will experience inevitable reductions in farm water supplies and hydroelectric generation.

‘Dead Pool’

Averyst vacationed at Lake Mead growing up – wakeboarding and waterskiing were among his favorite activities. Her great-grandfather was even one of the workers who built the dam, she said, which was completed in 1934. Its iconic U-shape, almost as thick as two football fields long, became a symbol of the hard work of Americans during the Great Depression.

But the lake is not the same as before, she says. As the water drains away, a muddier shoreline appears. “The way I characterize it is that it’s not shaped like an ordinary glass, it’s shaped like a martini glass,” Averyst said, so the lower the lake goes, the faster the shore recedes. .

The receding waters mean you have to wait hours just to put a boat on the lake due to all the ramps and docks being closed. Previously sunken boats are displayed on the newly bare shore. A decades-old intake valve, a WWII ship and human remains have shockingly emerged from the depths.

The Bureau of Reclamation predicts there’s a 1 in 5 chance the lake will fall to 1,000 feet by 2025, which is only 50 feet above the minimum level needed for Hoover Dam to produce water. electricity. And it’s only 105 feet above the dead pool level of the lake – the point at which water won’t flow freely through the dam and produce electricity. Instead, it would take electricity to pump water through the dam.

“We’ve already seen power generation at Hoover Dam drop by about 30 to 40 percent from peak capacity over the last 10 years,” Hoover Dam operations and planning manager John Jontry told CNN. energy to the Metropolitan Water District of Southern California.

Jontry’s agency receives about 1 million megawatt hours of electricity each year from the Hoover Dam, which it uses to help power pumps along the Colorado River Aqueduct to bring water from Lake Havasu – a reservoir at the Arizona-California border – towards southern California.

But water officials and hydrologists saw it coming: “The surprise was when it happened, not that it happened,” Averyst said.

That’s why about 10 years ago, the reclamation office made improvements to the Hoover Dam, including replacing the turbines that drive the power generators. The five new turbines have been designed to operate under a wider range of lake elevations, particularly at lower levels.

“As Lake Mead declines, we will continue to see (power) generation gradually decline,” Jontry said.

According to the office, states in Mexico’s Colorado River Basin, tribes, and power and water authorities are currently negotiating plans to conserve water and prevent Lake Mead from reaching the ” dead basin”, while stabilizing electricity production.

More unprecedented challenges ahead

Rehabilitation officials and local electricity and water agencies have already taken unprecedented action to deal with the escalating crisis. Due to falling Lake Mead water levels, the government last year announced a Level 1 shortage on the Colorado River for the first time, causing water outages for Arizona, Nevada and Mexico.

A similar challenge faces Lake Mead’s upstream neighbor, Lake Powell, the nation’s second-largest reservoir. Lake Powell’s water levels are about 44 feet from dropping to the point that the Glen Canyon Dam would not be able to generate hydroelectricity.

To keep Glen Canyon Dam in operation, the reclamation office announced in May that it was taking emergency action to release more water from upstream reservoirs while retaining water discharges from Lake Powell. itself, which generally sends water downstream from Lake Mead.

“When Lake Mead and Lake Powell were filled, it was about making sure there was water for the western United States, but it was also about making sure that ‘there was power available for the west,’ Averyst said. “And so what the federal government is facing right now is making sure that we continue to have water where we need it, but also that we can have enough water in each of the reservoirs to generate electricity.

As the Bureau of Reclamation prepares for a critical 24-month forecast report that will determine the next round of water cuts, its biggest goal is to keep Lake Mead from reaching ‘dead pool’ by continuing talks. and negotiations with.

Averyst and officials who spoke to CNN say there’s hope it won’t get to that point, and it’s just a matter of adapting. With more infrastructure funding coming from the federal government, she said it’s an opportunity to reanalyze the current system and find ways to manage and adapt to a warming future.

“We’ve always been innovative, and I think there’s a lot of room for water and energy conservation,” she said. “The problem with climate change is that it is going to have and in many cases impact our ways of life, and we are going to have to adapt and change the way we do things, because it is what we did and we have to live with the consequences.

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