
President Trump has repeatedly blamed Gov. Gavin Newsom and other California leaders for the fires that devastated Los Angeles. The president has charged that the state’s Democrats have stubbornly refused to send enough water to Southern California to fight fires, which he attributed to their desire to protect the delta smelt, a threatened species of fish.
But as Mr. Trump prepared a Friday visit to California, water experts in California said that his explanations in many cases were wrong or glossed over complex water dynamics. Southern California reservoirs were generally full of water at the start of the year, they noted, and problems in the fight against the fire had other causes.
Mr. Trump’s view of the situation could have very real consequences. He threatened on Wednesday to withhold federal relief funds if California does not send more of its water from the northern part of the state to its southern half. He also issued an executive order on his first day in office — titled “Putting People Over Fish” — that directed cabinet members to find ways within 90 days to reroute more water southward.
The order brings to the fore litigation and disputes as old as California itself around who deserves precious water in the state and how its liquid gold can best serve nearly 40 million residents along with its agricultural industry, fisheries and ecosystems.
The mountains along the spine of California — the Sierra Nevada and southern end of the Cascade Range — are an essential piece of the state’s water supply. The same storms that make Yosemite National Park a winter wonderland and create ski playgrounds near Lake Tahoe leave a snowpack that melts into streams and rivers by spring and summer.
While most of the state’s water originates and gets stored in Northern California, most of the state’s population lives in Southern California. And the water-intensive agricultural industry sits in the Central Valley, where rain is never enough to sustain each year’s crops.
“Look, Gavin’s got one thing he can do,” Mr. Trump said in an interview on Wednesday with Sean Hannity, the Fox News host. “He can release the water that comes from the north. There is massive amounts of water, rainwater and mountain water, that comes, too, with the snow, comes down as it melts, there’s so much water, they’re releasing it into the Pacific Ocean.”
But the state’s water supply to Southern California, experts said, had nothing to do with the fires that raged uncontrollably the night of Jan. 7 and destroyed more than 10,000 structures.
“There’s a lot of things you could say that will make California look bad, but this is not one of them if you want to do it factually,” said Jay Lund, a University of California, Davis, a professor emeritus who has studied water resources and environmental engineering.
When Mr. Trump and other Republicans criticize California for sending water into the Pacific Ocean, they are referring to agreements that ensure the state sends enough freshwater downstream to protect crucial ecosystems. Some of that water ultimately makes its way to the ocean.
It all comes to a head at Northern California’s Sacramento-San Joaquin Delta, where saltwater from the San Francisco Bay mixes with freshwater from rivers. The Delta is the largest estuary on the West Coast, one that is incredibly sensitive environmentally and politically.
Through the Delta, the state and federal governments supply tap water to two-thirds of the state’s population and irrigation water to millions of acres of farms, with a labyrinth of levees, pumps and islands controlling the balance of saltwater and freshwater. How much water to pump through the Delta has been the source of water squabbles in the drought-prone state for decades, and in that fight, the most politicized target has been one of its tiniest inhabitants: the delta smelt.
After the fires began, Mr. Trump called it “an essentially worthless fish” that Mr. Newsom wanted to protect.
Smelt were once plentiful in the Delta, playing an important role in the ecosystem by providing food to myriad species of fish and birds. Now teetering on the brink of extinction, they offer a different ecosystem benefit, experts say: Helping to protect other native fish that also need some amount of freshwater flowing into the estuary.
“There are a lot of different kinds of fish out there that need protection and need to be managed,” said Peter Moyle, professor emeritus at University of California, Davis, Center for Watershed Sciences. “The fish are going to disappear one at a time if we don’t take them into consideration.”
For decades, however, the smelt have come to represent one thing to many farmers in the Central Valley: a competing demand on their supply of water for irrigation.
This is not the first time that a Trump administration has taken aim at the delta smelt, a humble-looking fish that exists only in California. In 2019, it weakened protections for the fish, a move that was heralded as a win for farmers.
“If President Trump somehow manages to find a way to send more water south, his action will cause big problems with agriculture in the Delta and the northern half of the state,” Dr. Moyle said.
The smelt in question are one of seven threatened or endangered species of fish in the Delta harmed by the degraded habitat caused by diverting too much water, according to Jon Rosenfield, science director at San Francisco Baykeeper, an advocacy group. They include steelhead trout, green sturgeon and two varieties of Chinook salmon. Other Chinook have fared so badly in recent years that the state’s salmon fishery has had to close for the last two years.
“You’ll never hear Donald Trump or his allies talk about endangered Chinook salmon or the closed salmon fishery. You’ll never hear him talk about green sturgeon,” Dr. Rosenfield said. “Why? Because people know what salmon and sturgeon are.”
Even under the more restrictive rules that were in place until 2019, regulations that specifically related to delta smelt were responsible for no more than an average of 1.2 percent additional water flowing into San Francisco Bay, according to an analysis he helped conduct.