Lake Powell and Lake Mead hit record lows, threatening hydropower production

The water level at Lake Powell, the United States’ second-largest reservoir, has fallen to a record low, heightening concerns about the ongoing crisis in the Colorado River system. The alarming milestone at Lake Powell, reached Saturday, comes about a week after the river’s other major reservoir, Lake Mead, also hit a historic low. Plummeting water levels pose a major threat to the Colorado River Basin, which is a key resource for wildlife, hydropower and more than 40 million people in seven U.S. states. The historic lows come as the federal government and states that rely on the river — California, Arizona, Nevada, New Mexico, Utah, Wyoming and Colorado — struggle to reach agreement on a long-term management plan for the dwindling resource. Persistent overuse combined with a record-dry winter and rising temperatures have been depleting both Lake Powell and Lake Mead. Lake Powell’s elevation dropped to 3,519.91 feet (1072.9 meters) above sea level on Saturday, dropping just slightly below a previous record set in April 2023, according to data from the U.S. Bureau of Reclamation. The lake is more than 20 feet (6.10 meters) lower than it was at the start of the year, USBR data shows. The reservoir is now about 30 feet (9.1 meters) away from the point at which turbines would stop producing hydroelectric power. Federal officials warned in April that a “major intervention” would be necessary to avoid reaching that threshold by the end of this year. USBR in July proposed a 10-year plan that includes major potential water cuts for Arizona, California and Nevada. The crisis has been in the making for years. Both reservoirs are at the lowest they have been in nearly seven decades, and levels may continue to drop, USBR data shows. The last time their combined storage was this small was in May 1957 when Glen Canyon Dam that holds back Powell was being built, according to a recent paper published by a group of academics and retired water officials. Powell began to fill in 1963. The depletion has also impacted Lake Powell’s substantial tourism industry, forcing marinas in the reservoir to adapt. Boat ramps have closed or moved, new ones are being added and marinas have been temporarily relocated to deeper waters. Lake Mead hits historic low water level as Colorado River struggles Lake Mead, the largest reservoir in the United States, has plummeted to its lowest water level since it was filled some 90 years ago, another sign of the crisis plaguing the Colorado River system. Water levels at the reservoir, which straddles the Arizona-Nevada border outside Las Vegas, hit 1,040.4 feet (317.1 meters) above sea level on August 7, according to federal data. That’s just below the record set on July 28, 2022, according to the U.S. Bureau of Reclamation. “It’s extremely significant and extremely concerning. You have three-quarters of the population of the Colorado River Basin, some 30 million people, who are directly impacted by risks to Lake Mead,” said J.B. Hamby, chairman of the Colorado River Board of California and a board member of the Imperial Irrigation District, the largest user of the river’s water. Hamby said it is vital for states that use Colorado River water to reduce water use. Drought and dry conditions have stretched along the length of the Colorado and are particularly intense at its source in the Rocky Mountains. Melting snow provides important water for the river. This past winter, however, saw the worst snowpack on record for the Colorado River Basin, adding more stress on farmers, industry, wildlife and hydropower producers, as well as the 40 million people across seven U.S. states, tribal nations and Mexico who rely on the waterway. Years of overuse combined with drought and rising temperatures have been depleting Lake Mead and Lake Powell, the country’s second-largest reservoir. Both are the lowest they have been in nearly seven decades. To protect the strained system’s ability to produce hydropower, federal officials said that they will not release cool Lake Powell water from Glen Canyon Dam in northern Arizona to protect a threatened native fish, the humpback chub, whose habitat is between the reservoirs. Federal officials recently announced a short-term proposal to stave off a crisis in the beleaguered waterway, after states that rely on it — California, Colorado, Arizona, Nevada, New Mexico, Wyoming and Utah — failed to reach an agreement on how to share the dwindling resource in the long term. The federal proposal called for the Lower Basin states of Arizona, California and Nevada to take less water. The Bureau of Reclamation, which released the plan, said it was flexible: Deeper cuts could happen in drier times, while states would have more time to collectively agree on how to manage the scarce resources. Severe drought in 2022 on Lake Mead, which is held back by Hoover Dam, exposed human remains and forced water officials in Las Vegas to pump water from deeper within the reservoir to continue to supply water to millions of people. Lake Mead and Lake Powell are not alone. Of the 54 Western reservoirs tracked by the Bureau of Reclamation, nine recently recorded their lowest levels in the last three decades. Federal officials do not believe the record will stay where it is. According to modeling done in July, Lake Mead is forecast to continue dropping through much of the rest of the year.