Record low water at 2 major lakes poses a threat to humans and wildlife in the West

Water levels at Lake Powell and the Great Salt Lake have reached their lowest levels ever amid drought that has racked the West for years and is being exacerbated by climate change.

Lake Powell, which straddles the Utah-Arizona state line, has reached its lowest levels since the massive man-made reservoir was created in 1963, according to data from the U.S. Bureau of Reclamation. Situated along the Colorado River, the lake is a major water supply for more than 40 million people across seven U.S. and two Mexican states.

The water level at the Great Salt Lake in Utah also hit its lowest point in history, breaking the previous record from 1963, according to data from the U.S. Geological Survey. The 1,700 square mile lake – the largest salt water lake in the Western Hemisphere – is home to millions of birds that find sanctuary there.

The low water levels could have major consequences for the Southwest, said John Berggren, a water policy analyst for Western Resource Advocates.

"It's a limited water supply, in the desert. You need water to do pretty much anything," Berggren said.

Agriculture is a massive drain on reservoirs since crops growing in the arid, Mediterranean climate require a large percentage of the Southwest region's available water supply, said Department of Agriculture analyst Brad Rippey.

But concerns extend way beyond food and drinking water.

Water levels are important to maintain in order to keep the lakes open for recreation and, more importantly, to keep the power on. The cities clustered around Lake Powell rely on hydropower that generates electricity for millions in the region.

At Lake Powell, water levels need to remain above 3,490 feet for turbines to continue running smoothly. The lake level is currently hovering around 3,550 feet.

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A depleted water supply and stalled power grid could halt municipal operations and development in the surrounding cities and towns. In response to the drought, several towns in Utah have already announced a moratorium on all development.

Additionally, low water levels in Lake Powell could lead to lower levels in the Colorado River. Shallow waters there would lead to higher river temperatures that could have major ecological ramifications.

Over the past century, there have been numerous legal battles and congressional decisions on the management of the Colorado River. But in the past 20 years, the basin states have shifted their focus toward collaborative efforts to distribute the water supply.

Now, Breggren is concerned that climate change could cause drought conditions to become so severe and unrelenting that states may take their disputes to court. And Breggren said local governments could inadvertently threaten agriculture by buying up water rights.

"Water in the West is so contentious and it's so embedded in Western society that people don't give up water readily or without a fight," Breggren said.

Berggren said strategic and proactive policy measures are needed. "A drought doesn't just flip on and off."

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The water crisis that's now facing the Southwest has been developing for two decades, the USDA's Rippey said. He helps author the US Drought Monitor map, which currently shows extreme and exceptional drought covering about 90% of the West.

Climate change is exacerbating drought conditions in multiple ways that compound to accelerate water loss, Rippey said.

High temperatures, like those in the West that have broken records this summer, lead to increased rates of evaporation and evapotranspiration, or water loss from soil and plant surfaces. Making things worse: The little rain and snowfall the region does receive is being absorbed by the parched ground at high rates, leaving less for lakes and rivers.

Rippey said tree ring patterns dating back centuries show droughts that lasted for decades and likely uprooted civilizations. He said it's possible the West is in for another 20 to 40 years of dryness.

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The natural decline in water levels, which has put many bird and fish species at risk, is compounded by the great human demand in the populous Southwest region.

"There's not only competition from nature but growing human settlements," Rippey said. "So, there's ever competing interest for limited resources."

Contributing: Lindsey Botts, Arizona Republic; The Associated Press

This article originally appeared on USA TODAY: Great Salt Lake, Lake Powell record lows amid drought in West