On the morning of January 10, 1862, Leland Stanford, the industrialist and railroad magnate who would later lend his name to Stanford University, departed his mansion, in downtown Sacramento, en route to the state capitol building, about five blocks away. Stanford was preparing to be sworn in as the eighth governor of California. He had to abandon his grand plans to travel in style, via horse-drawn carriage, however. Sacramento lay under as much as eighteen feet of river water after the region’s second major flood in as many months. Weeks of downpour had caused the levees on the American River and the Sacramento River to breach. While residents fled in droves, the Governor-elect likely travelled to the capitol via rowboat. One can imagine the oars disappearing into the brown murk as the detritus of a ruined city drifted by.
By the time that Stanford had placed his hand on the Bible and floated home, the floodwaters had risen so high that he and his wife reëntered the mansion through a second-story window. “The scenes of horror . . . defy description,” a guest at Stanford’s inauguration later wrote. “Cracking, falling, floating houses; businessmen ruined in an hour; strong men struggling for life in the current of our streets. Many of all ages and both sexes clinging to houses and floodwood, shrieking in despair, some sinking in death, and flood still rising!” In the end, rain fell for more than forty days; the deluge stretched from Oregon to San Diego, and as far east as Utah and Arizona. Sacramento was underwater for months. The legislature and governor’s office temporarily moved to San Francisco. (The state Supreme Court moved there and never left.) Thousands of people are believed to have died. Even more cattle perished, and a drought followed, forcing the state to abandon much of its livestock economy in favor of crops.
The storms that have buffeted the state since December 31, 2022, evoke scenes from the great flood that afflicted Stanford’s inauguration. In recent days, gale-force winds toppled century-old trees onto cars and homes in Sacramento; ocean waves wiped out a portion of a pier at Capitola, in Santa Cruz County; rivers have exceeded their capacities, running over banks and into residential streets and homes. President Biden declared a state of emergency; tens of thousands of people have been displaced.
Meteorologists and climate scientists identify these recent tempests as atmospheric rivers—columns of vapor that worm through the atmosphere, carrying moisture from the tropics. In the air above the Pacific, atmospheric rivers can contain as much water as the Mississippi; when they expel their moisture in the form of rain and snow, they can leave death and destruction in their path. On Wednesday evening, only eleven days into 2023, atmospheric rivers had already claimed the lives of at least eighteen Californians. A two-year-old boy was struck by a falling tree in his house in Sonoma County; rescuers are still searching for a five-year-old boy swept away from a car by floodwaters in San Luis Obispo County.
The Great Flood of 1861-62 and its lessons had largely disappeared from public memory until 2010, when a study funded by state and federal agencies, dubbed ARkStorm—short for Atmospheric River thousand-year Storm—modelled a hypothetical weather event based in part on the great flood. (Though its name suggests that such an event happens every thousand years, the geologic record shows that it actually occurs every hundred to two hundred years.) At the time, the U.S. Geological Survey estimated that this storm—a when-not-if proposition—would inflict some seven hundred and twenty-five billion dollars in damage and economic loss.
Strangely, that broad, multi-agency study did not take climate change into account. In 2010, “climate was a pressing issue,” Karla Nemeth, who works under Governor Gavin Newsom as director of the California Department of Water Resources, told me, last summer. But, because fewer people had experienced life-threatening climate disasters then, funding research into climate change required a great deal of political will, Nemeth said. It was difficult to convince Californians that climate change could cause a deadly influx of surplus moisture, particularly during a years-long drought.
More recently, a research team co-led by Daniel Swain, a U.C.L.A climate scientist, has been updating the 2010 report to factor in human-caused climate change. So far, the results of ARkStorm 2.0 render the astonishing predictions of the original study twice as terrifying. “Climate change over the past century has doubled the risk of an extreme winter storm sequence capable of causing widespread, severe flooding,” Swain and his research partner wrote in a summary of their study, which was published in the journal Science Advances, last August. Even so, the scientists have struggled to sustain funding for their research. “I think there’s an interesting undercurrent of not wanting to know, because then you would actually have to deal with the problem,” Swain told me last year.
As California’s ongoing storms increasingly dominate headlines, leaders in Sacramento appear to now be acknowledging the threat. Earlier this week, Newsom proposed two hundred and two million dollars in funding for flood prevention in his 2023 budget, supplementing the seven hundred and thirty-eight million invested in flood-protection programs over the previous two years. Swain has seen renewed interest in his work. “I’m getting e-mails every week now from governmental entities wanting to talk about our storm,” he said, of ARkStorm 2.0. Swain has been speaking regularly with officials like Nemeth, who has supported ARkStorm research since its inception. “I think I scared her a little bit,” he told me. That fear may be what’s required to get the rest of the state on board.
In June, 2022, I attended the annual California Extreme Precipitation Symposium, in Folsom, about half an hour east of Sacramento. Some sixty in-person attendees had gathered in a hotel conference room and, along with online participants, reckoned with the power and peril of the state’s rivers—both those on the ground, like the American and the Sacramento and the Russian, and those that flow through the sky. Meteorologists and hydrologists—nearly everyone in attendance seemed to be a government -ologist of some kind—spoke of atmospheric rivers and changing watersheds and the glut of forecasting technologies that purport to help avert disasters.
The tone was clinical and sedate. With few exceptions, the presenters gave the impression that, thanks in part to human ingenuity, things were under control; it did not sound like the destruction of the Great Flood of 1861-62 would repeat itself. “We’ve built all these dams upstream,” Gary Estes, who has run the symposium since 1994, told me. “We have a new spillway, we have forecast-informed reservoir operations. We’ve built levees way bigger than existed back in 1862.”
Later, one of the presenters, Gary Bardini, of the Sacramento Area Flood Control Agency, took me on a tour of the region’s flood-prevention projects. It was the second day of summer, the air was an oppressive ninety-seven degrees, and green vegetation was already turning yellow. The Sacramento and American Rivers were low and docile. For three hours, we explored miles of rural Sacramento, walking alongside weirs and levees, some of them actively under construction. Dump trucks with tires twice my height rolled past us, ferrying dirt like so many ants, building what Bardini and his fellow-engineers hope will be unbreachable barriers.
Bardini spoke of past floods, including one, in 1986, that breached a levee near the confluence of the Yuba and Feather Rivers, drenching four thousand homes and causing nearly half a billion dollars in damage. Standing outside in the summer heat, surrounded by signs of California’s megadrought, I could understand why water calamities are hard to imagine until they happen. But imagination is just what climate change demands.
The state’s struggle against devastating floods will depend, in part, on residents who will need to prepare even when there is little water in sight, Nemeth, the Department of Water Resources director, told me. Even progressive California sometimes lacks the political will to fund research and flood-mitigation projects, and misinformation about the climate crisis—as Nemeth put it, “three decades of just a lot of fundamental questioning of ‘Is climate change even real?’ ”—continues to get in the way. But Swain told me that there are now promising signs that ARkStorm 2.0 could soon be fully funded. If so, the project will be able to map out where the deadliest flooding is likely to occur.
The storms now soaking California have yet to reach ARkStorm 2.0 proportions; such a calamity would require several more weeks of back-to-back, even more extreme precipitation, which aren’t currently forecasted. Still, Swain, like other scientists, sees what he considers the direct impact of human activity altering the Earth’s atmosphere. “Warming temperatures increase the water-vapor-holding capacity of the atmosphere,” he told me. “So we’re probably at a point where extreme precipitation events, on average in the world, are about ten to fifteen per cent more intense than they would have been.” In other words, this storm is bad. The next big one is likely to be worse. ♦
