Tulare Lake Was Drained Off the Map. Nature Would Like a Word.

CORCORAN, Calif. — It is no secret to locals that the heart of California’s Central Valley was once the largest body of fresh water west of the Mississippi River, dammed and drained into an empire of farms by the mid-20th century.

Still, even longtime residents have been staggered this year by the brute swiftness with which Tulare Lake has resurfaced: In less than three weeks, a parched expanse of 30 square miles has been transformed by furious storms into a vast and rising sea.

The lake’s rebirth has become a slow-motion disaster for farmers and residents in Kings County, home to 152,000 residents and a $2 billion agricultural industry that sends cotton, tomatoes, safflower, pistachios, milk and more around the planet. The wider and deeper Tulare Lake gets, the greater the risk that entire harvests will be lost, homes will be submerged and businesses will go under.

Across the region, the surprise barrage of atmospheric rivers that swept through California over the past three months already has saturated the ground, overflowed canals and burst through levees. The fear now is that record walls of snow in the southern Sierra Nevada will liquefy in the intensifying spring heat into a downhill torrent that will inundate the Central Valley.

And the resurrected Tulare Lake (pronounced too-LAIR-ee), already wider than all but one of the California’s reservoirs, could remain for two years or longer, causing billions of dollars in economic damage and displacing thousands of farmworkers while transforming the area into the giant natural habitat it had been before it was conquered by farmers. “The Big Melt,” unsettled meteorologists have begun to call it.

“This could be the mother of all floods,” said Phil Hansen, 56, a fifth-generation farmer who has already lost more than a third of his 18,000 acres to a breached levee. “This could be the biggest flood we’ve ever seen.”

Already, several communities have been evacuated, and hundreds of homes and farm buildings have been destroyed or damaged. Sandbags are being helicoptered in. Dairy cattle have been hustled to higher ground by the tens of thousands. The authorities said last month that a local poultry facility surrounded by water was weighing whether to move or slaughter a million chickens. And farmers are sparring over whose land should get flooded first, knowing that inundation likely will be a question of when, not if.

In the lake’s revival, scientists, historians and growers see an epic rematch gathering between nature and humans. For now, nature seems determined to win in an era of climate change with extended dry periods followed by storms that deliver more water than anyone knows what to do with. The runoff has no natural place to drain, and experts say there is no easy way to send this water to other areas of the state that could use it for irrigation or residential purposes, even as the state remains desperate for long-term drought solutions.

Around the farm and prison town of Corcoran, gray-blue waves now whoosh surreally to the horizon. Snowy white cranes soar over dirt levees that, so far, are shielding some 22,000 residents and inmates. Submerged fields lie bereft of the tomatoes and Pima cotton that would ordinarily fill them, an agricultural Atlantis larger than Manhattan.

The lake bed is essentially a 790-square-mile bathtub — the size of four Lake Tahoes — that dates back to the Ice Age. Mammoths once sipped at Tulare Lake’s shores, and tule elk ranged in its marshlands.

Now the landscape is among the most heavily engineered in the nation. Great dams, run by the federal government and underwritten over the years by large growers, manage the water released into it from the Kings, Tule, Kaweah and Kern Rivers. Downstream, farmers and cities have erected hundreds of miles of levees and canals.

High in the southern Sierra Nevada, a record snowpack, triple the historical average, will strain the water managers who are already running that plumbing system like never before as the days lengthen and the spring skies heat.

The load of water waiting to course downhill dwarfs what is there already. It is so immense that officials project that in addition to expanding Tulare Lake, it will fill the area’s four largest reservoirs two or three times over. If the snow melts too fast, it could overwhelm flood protections, wiping out crops and inundating already-saturated farm towns. Veterans of past floods say that, even with all the fortifications in place, the lake could spread to 200 square miles or more.

“We have no control over nature, and we have no control over the water flows that are coming around us,” said Greg Gatzka, the city manager of Corcoran, where county authorities have repeatedly expressed concern about the height of the levees.

In 1983, when a long-lasting snowmelt submerged about 130 square miles of the lake bed, the damage just in Kings County cost nearly $300 million in today’s dollars, and the water took two years to clear, according to John T. Austin, the author of “Floods and Droughts in the Tulare Lake Basin,” a book about the region. That summer, two men kayaked through the floodwaters from the banks of the Kern River just outside downtown Bakersfield to the San Francisco Bay, a meandering 450-mile journey across what would typically be sun-baked land.

Since then, the population has roughly doubled, both in Kings County and in the surrounding San Joaquin Valley that includes Fresno and Merced, a region that is now home to about three million people.

Mark Grewal, an agricultural consultant and former executive at the dominant J.G. Boswell Company, one of the largest privately owned farms in the nation, said that the long-term, regionwide economic impact could be exponentially higher than in 1983 because the commodities that are now grown — high-end crops such as nuts, tomatoes and Pima cotton — are much costlier and are spiking in value with inflation. The region is so crucial to the world’s supply that sustained substantial flooding could lead to higher prices for consumers.

Emergency officials have sought to drive home the enormous catastrophe that could develop as the thaw comes.

David Robinson, the sheriff of Kings County, recalled that he was 12 years old when the 1983 flood hit, and he never imagined he would see such a spectacle twice in his lifetime. In an interview, his assistant sheriff, Robert Thayer, said aerial footage was not reassuring. Both men described the potential for flooding as “biblical.”

“This will impact the world, if people can just grasp that,” Sheriff Robinson said at a news conference after asking the public to stop using the lake for boating. “We’re going to have a million acre-foot of water covering up an area that feeds the world.”

In Corcoran, city officials are struggling to keep the roads open and waiting for the state to decide whether to evacuate 8,000 inmates from two prisons. Brian Ferguson, a spokesman for the California Governor’s Office of Emergency Services, said that local power plants, oil wells and derricks are also an intense concern. Gov. Gavin Newsom issued an executive order on Friday that was intended to accelerate flood preparations in the Tulare Lake basin, and a team from the California Department of Forestry and Fire Prevention arrived last month in neighboring Tulare County to prepare for a potential disaster.

But coordination on the ground has been fraught.

At tense emergency meetings last month, farmers claimed that rogue actors were secretly cutting holes in levees, violating longstanding traditions about the order in which farms were supposed to be flooded in wet years.

At one session, a public works official in Corcoran reported that the city had posted an armed guard at the levees protecting it. At another, county authorities thanked farmers for refraining from engaging in fistfights. Kings County has twice ordered the Boswell Company to release some floodwater onto its own land.

In smaller towns, residents worry that the protection of their homes will be at the mercy of powerful growers.

“All around, if you drive in your car, it’s just water everywhere,” said Cecilia Leal, 27, who lives across the county line in nearby Alpaugh, where evacuations were ordered last month after a levee breach. “You turn, there’s water.”

She and her parents stayed behind for Cesi’s Cafe, the family restaurant they operate from the front of their house on a country road. But only one route into town is open, and she said she feared the town’s only gas station would run out of fuel.

A video of desperate pistachio growers launching two dirt-filled pickup trucks into a local levee breach has gone viral. At the Lake Bottom Brewery and Distillery in Corcoran — which finally was compelled to end its $3-a-pint drought-related “Pray for Rain” special — Fred Figueroa joked that he and his sons, who own the bar, were considering naming their latest beer “Two Chevys in a Levee.”

Nature’s ascendance is not all bad news. Birds that once wintered at Tulare Lake — ibises, blackbirds and American coots — are returning in increasing numbers. On a recent sunny afternoon, a row of pelicans glided over drowned furrows, and long-legged herons rested on the muddy banks of a drainage canal near Alpaugh. A tiny bird with tall, skinny legs and a black ring around its neck scuttled across the road.

Navigating his white pickup truck last week across a tilled landscape that might soon be underwater, Mr. Grewal, 66, the consultant, said there was no way these flatlands, stretching for miles under wide blue skies, would avoid inundation. He said the melting snow would have far worse impacts than the flooding that had already occurred.

“A heavy snowmelt in May is going to be a disaster,” Mr. Grewal said. “This lake could cover hundreds of square miles here by the time everything comes down.”