Low-level Hoover Dam tests, historic floods could buy time in hydropower crisis

Sitting on a wooden plank covering the original terrazzo floor of Hoover Dam’s underbelly is a big, stationary hunk of steel.

Turbine A8, the eighth turbine on the Arizona side, is one of only five wide-head turbines at the dam that are primed for drought, able to function with water levels below 1,035 elevation at Lake Mead without guaranteed risk of permanent damage. A8 has been out of commission awaiting repairs for months.

The dam has 17 turbines in all. Now, Lake Mead’s projected decline could spell crisis for rural utilities across Nevada, Arizona and California that have counted on Hoover Dam hydropower for decades.

The federal government intends to see how far it can push the dam’s infrastructure. Bureau of Reclamation spokesman Peter Soeth said the agency will, for the first time in history, test whether those older turbines can operate at lower water levels, with strict limits on operating hours as well as monitoring and frequent inspections to ensure safety.

“The testing results will clarify the shutdown elevation and provide Reclamation a more accurate picture of the facility’s capacity as reservoir levels decline,” Soeth said.

Devastating floods have given reservoirs a glimpse of life

Luckily for the feds, the record floods across the Colorado River Basin, fueled by what scientists are calling a “Super El Niño” weather pattern, may buy Hoover Dam some extra time.

A steady rush of rain this past month left one dead in Henderson during a water rescue, devastated Native American settlements in Arizona and New Mexico and even complicated travel to the polls on Election Day.

Yet counter to traditional wisdom that says rain doesn’t mean much for the Colorado River’s biggest reservoirs, flooding has been significant enough that the runoff has translated into a stunning amount of storage.

Lake Mead, which provides about 90 percent of Southern Nevada’s water supply, has risen more than 2 feet since late October to reach elevation 1,039.41 as of Friday. Farther upstream, Lake Powell has risen about 19 feet since it fell to a record low in September.

The Bureau of Reclamation won’t make another decision about how much water to release from Lake Powell until April 2027, meaning Lake Mead’s water levels may keep falling over the next year despite the extra storage.

Prior projections from the Bureau of Reclamation had placed Lake Mead below elevation 1,035 by the end of October.

“We are very appreciative for every drop of water that gets in the reservoir,” said Colby Pellegrino, deputy general manager of the Southern Nevada Water Authority.

But that’s cautious optimism at best.

Pellegrino said the water authority’s climate modeling could suggest that warmer temperatures overall are shifting how water reaches the basin’s reservoirs. While the average amount of water is charting the same course of expected decline, water may begin to come as rain rather than snow.

In addition to that prospect, Pellegrino acknowledged that the supercharged El Niño pattern, where temperatures in the Pacific Ocean can bring big storms to the American West, is adding an element of unpredictability.

“This is sort of a snapshot of what that could actually look like for the basin,” Pellegrino said. “And I think that’s somewhat terrifying for our river communities and how they adapt to that.”

Elizabeth Koebele, a professor at the University of Nevada, Reno, who studies how the Colorado River is governed, said it’s important for decision-makers and the public to not discount the larger predicament that faces the basin.

“We can be grateful for seeing our reservoirs rise a little bit,” Koebele said. “But we also need to remember that isn’t the end game. It isn’t going to be the thing that gets the basin out of the current state that it’s in.”

What do these new tests mean for utilities and ratepayers?

Hearing about the Bureau of Reclamation’s plans for Hoover Dam operations initially worried Eric Witkoski, executive director of the Colorado River Commission of Nevada, until he learned the details.

“Before, I was very concerned,” Witkoski said. “Are you just going to run it down, pull it out and see if you damage it or not? But I walked away with a much better sense that they have ways to gauge it and watch for it and be able to shut them down.”

Witkoski’s commission manages the Silver State’s share of Hoover Dam’s hydropower. Utilities throughout the state in Lincoln County, Boulder City, Overton and other places have historically relied on the dam to power their communities.

This year, the commission has worked to provide its members with a dashboard that has specific information about how much power they can expect to receive at different lake levels, Witkoski said. Utilities have been preparing to buy power through the nation’s wholesale energy market to fill the gap, he said, though pricing can be volatile.

Witkoski called the range between elevation 1,025 and 1,035 feet at Lake Mead a “gray area,” meaning uncertainty exists as to how much power utilities may be able to buy during those low-level experiments.

In the long term, the Bureau of Reclamation is still working on utilizing new funding from the federal Help Hoover Dam Act to replace at least two older turbines with wide-head ones, allowing them to work at low levels.

Soeth, the agency spokesman, said he expects the first new turbine from that pool of money to be installed in 2028.

The extra breathing room from recent floods is welcomed, Witkoski said, but he remains concerned about the basin’s future.

“As the water folks will tell you, we’ve had a drought for over 20 years, so we’ve got a long way to go,” Witkoski said.

Contact Alan Halaly at ahalaly@reviewjournal.com. Follow @AlanHalaly on X.