What Lake Mead Needs To Get Water Levels Back Up at Drought-Hit Reservoir

Lake Mead will need more than just rainfall to replenish itself, an expert has told Newsweek.

Spread between Nevada and Arizona—Lake Mead, the largest man-made reservoir in the U.S.—is best known for its rapidly declining water levels due to the ongoing megadrought gripping the western states. The lake is integral to surrounding communities, as it is also formed by the Hoover Dam on the Colorado River—which generates electricity for thousands of people. If the water levels continue to decline, the consequences could be catastrophic.

Water levels at the lake have risen slightly thanks to heavy rainfall sweeping across the region.

But even this will not completely counterbalance the drought-stricken reservoir.

Jennifer Pitt, Colorado River program director with the National Audubon Society, an environmental organization, told Newsweek: "The vast majority of water in the Colorado River is created by snowfall in the mountains of Colorado, Wyoming, Utah and New Mexico. To refill the Colorado River reservoirs, you would need three average years of snowfall without any water use."

The reservoir uses both rainfall and winter snowpack to replenish its water levels. With the ongoing drought, these weather patterns are becoming more unpredictable and the lake isn't filling up as much as it once did.

During dry conditions, people also use more water, meaning that it is emptying faster than it can replenish itself.

Many scientists believe urgent policy changes in the region are needed in order to change this.

"There's been a good start to the snowfall season, but it is way too early to know what runoff will look like," Pitt said. "Today the water uses allowed by law are more than the river gets in an average year, so until the rules are changed it is unlikely the reservoirs will fill."

Does Rain Help Water Reservoir Levels?

The influx of rain pummeling Nevada and neighboring state California is likely to raise the lake's water level slightly—as will the snowpack that built up during the recent winter storms.

The sudden rainfall sweeping the region has even changed Nevada's normally static drought status. The U.S. Drought Monitor has changed Nevada's status to 0 percent in an exceptional drought, due to the rainfall. Last year, Nevada had a status of being 8 percent in an exceptional drought. However the state is still 24 percent in an extreme drought and 78 percent in a severe drought.

This means that the rainfall is unlikely to help the situation much in the long run.

Lake Mead's water level stands at 1,045 feet as of January 8. This is 21 feet lower than the levels recorded at the same point in 2022, and 38 feet lower than the same point in 2021. Over the years, the lake water levels have continued to decline.

In 2022, the lake hit its lowest level ever, at 1,040 feet. But 2022 was also the first year that the water levels rose since 2019. This was down to a particularly wet monsoon season. However, that only caused it to rise by a few feet.

This is because this stretch of drought gripping the region has been drier than any other recorded in the U.S. in the past 1,200 years. Scientists are putting it mainly down to human-driven climate change.

As it has been dry for so long, there is a possibility that not much of the rain will not even make it into reservoirs.

Matthew Lachniet, professor and chair of geoscience, at the University of Nevada, Las Vegas, told Newsweek: "The wet weather will help [water levels], for sure. But the upper basin has been dry for a long time, so that the soils will still be absorbing a lot of water before it will end up efficiently turning into stream runoff to replenish the lake. If we had a string of three to five more wet winters, and if those winters stay wet through April of each year, it will start to have an effect on inflow into Powell and Mead reservoirs."

Last year was the driest one yet for the reservoir, and the Bureau of Reclamation estimates 2023 will bring more of the same.

Andrea K. Gerlak, professor at the School of Geography, Development & Environment at the University of Arizona, told Newsweek that it is important not to let the rainfall in California distract from the dire situation.

"The Bureau of Reclamation's latest studies expect water flows to continue to decline in the Basin this year. It is easy to lose sight of this when we see the heavy rains and flooding in California, and the destruction they have brought to some communities," Gerlak said. "But we have a long way to go to begin to pull ourselves out of this 20+ year drought in the larger Colorado River basin."

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