Extreme Heat Could Also Mean Power and Water Shortages

Across the Western United States, signs of a parched present—and future—are everywhere. From wildfires burning across the Pacific Northwest to California’s shrinking reservoirs, it appears as if the earth is extremely dry for the second summer in a row. As of July 22, 75.6 million people are living under drought conditions, according to the US Drought Monitor, a report produced weekly by hydrology experts at the National Oceanic and Atmospheric Administration, the US Department of Agriculture, and the National Drought Mitigation Center at the University of Nebraska, Lincoln. One quarter of the continental US is experiencing “extreme or extraordinary drought,” according to the report.Despite some summer rains in parts of the desert Southwest earlier in July, experts say the situation is likely to get worse in the coming months, and that the region’s cities and farms should prepare for possible shortages of both electricity and water. “The spatial coverage of drought in the West is huge right now,” says Dan McEvoy, assistant professor of climatology at the Desert Research Institute in Nevada, who studies the causes and effects of western droughts. “Nearly every state, or every state in the western US, has some level of drought. And California is pretty bad.”As he spoke with WIRED during his vacation last week, Jay Lund, a professor of civil engineering at UC Davis, was sailing his family’s 36-foot boat past a brand-new 800-foot rock wall across a section of the San Francisco Bay Delta. The 1,100-square-mile delta forms at the confluence of the Sacramento and San Joaquin Rivers and is home to 750 species of plants and wildlife. But because of the lack of rainfall this year, and lower snowpack in the Sierra Nevada mountains, the two rivers aren’t flowing enough to keep saltwater from the nearby San Francisco Bay flowing upstream and entering the delta. “This is an extreme drought,” Lund said while waiting for a breeze to pick up—the third driest on record in California, behind the droughts of 1976 and 1924, since record-keeping began in the early 20th century.The sparse rainfall and low water levels are one reason that state officials in June built a $10 million emergency project—the size of San Francisco’s Transamerica Pyramid laid on its side—to keep ocean saltwater from surging into the delta. They hope to protect its freshwater supplies, which are diverted to massive pumps that pipe drinking water to 27 million California residents from San Jose to Los Angeles, and irrigation water to farmers across the fertile Central Valley.California has started limiting groundwater withdrawals for the state’s farmers, who account for $50 billion, or 3 percent, of the state’s GDP. But, so far, Governor Gavin Newsom has only encouraged, rather than required, state residents to cut home water use, such as lawn watering, by 15 percent.Still, there are signs of a growing concern about the looming water crisis in the Golden State. Lund, who has developed large-scale models of the state’s water supply, says August will be hotter and drier, and he expects more demand on the state’s electric grid and less available water. “This is a warm drought, and the higher temperatures are going to make the air-conditioning load higher, particularly in the evening hours when energy from solar power tails off,” says Lund. “That’s the major threat.”But, he says, there will be less surface water to drive hydropower dams in California. “My guess is that we're going to have half or less of the total hydropower than we normally have,” Lund says, “just because there's less rainfall.”