President Trump says California is wasting water that can be used to fight wildfires ravaging the state, but dousing water onto flames is not even the primary means to fight wildfires.

“For someone who lives in a city like President Trump, you might think of putting out a fire with a hose, and you can understand why he might think that,” said Michael Wara, a research fellow at Stanford Law School focused on climate and energy policy. “It’s just not the way wildfires are controlled. When you have 200 square miles with fire, there is just no way you can put it out with water.”

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Firefighters do use water as a secondary resource to put out wildfires. But mainly, firefighters extinguish wildfires by building fire lines around them to contain their spread.

Firelines are circular boundaries that firefighters create by using bulldozers to clear away all living material, such as brush, that can fuel more fire. Officials scrap down the boundary area so that there’s just bare dirt left. They get rid of this flammable material by lighting controlled fires.

“You are essentially creating a 10-foot road around the fire,” Wara said. “The fire burns up to that and stops, because it can't cross where there's no fuel. Containing the problem is the best you can do with a wildfire."

Trump, in the first of two tweets he posted Sunday and Monday, said California wildfires “are being made so much worse by the bad environmental laws which aren’t allowing massive amount of readily available water to be properly utilized.”

The largest of 17 wildfires active across California have destroyed more than 470,000 acres, affecting 40,000 residents, according to the Los Angeles Times .

The Carr Fire, which started scorching parts of Northern California near Redding two weeks ago, is the deadliest blaze. It has claimed at least seven lives.

Trump, in his first public comments on the fires Sunday, also blamed barriers to forest management, or the process of removing trees and vegetation in forests to control fires.

But Trump expanded on his water policy comment on Monday, writing that California officials are allowing water to “foolishly [be] diverted into the Pacific Ocean.”

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The president appears to refer to the long-running controversy over diversion of water away from people in Northern California in order to provide a habitat to preserve endangered fish species. Some Republicans in Congress have called for a larger water allocation for farmers in California’s Central Valley, which has suffered from drought.

But Trump is suggesting that this would make the water more available for firefighting efforts. State officials say water access is not a problem for California's firefighting efforts.

Water is typically used to slow down a fire if it approaches a fire line barrier, for example, or to stop a fire from encroaching on a home.

To collect water, firefighters use helicopters to lower buckets into lakes and ponds and dump it onto the fire.

“There is no environmental regulation that prevents firefighters from accessing any body of water they want to use in the state,” said LeRoy Westerling, a management professor at the University of California, Merced, who studies wildfires. “It's not their first choice, and it's not a binding constraint in any way.”

Cal Fire officials who are responding to California’s wildfires say major reservoirs are located near the worst fire areas. The Carr Fire, for example, is near Lake Shasta. State officials, including Gov. Jerry Brown, a Democrat, have blamed climate change for making the wildfires bigger and longer-lasting due to hotter and drier weather.

“We have plenty of water to fight these wildfires, but let’s be clear: It’s our changing climate that is leading to more severe and destructive fires,” Daniel Berlant, assistant deputy director of Cal Fire, told the New York Times .

Federal government officials who specialize in firefighting response cite other reasons for more destructive wildfires, including the fact that fires are increasingly burning close to homes and people as the West becomes more populated.

“We can speak to what we know, and what we are seeing is the factors contributing to above- normal fire behavior are extended years of drought, hotter temperatures, and the continued expansion of people building homes in natural areas that are vulnerable to wildfire,” Jessica Gardetto, a spokeswoman for the National Interagency Fire Center, told the Washington Examiner. “Change in climate and the weather is causing us to have longer fire seasons."

Trump did make one important point in his tweets, experts say. Fights over water access among cities, farmers, and environmentalists in California is contentious and a problem. But the dispute is unrelated to fighting wildfires.

“We’ve been fighting about who gets how much water for 100 years, and that continues to be a bone of contention certainty among some of the president’s supporters,” said Peter Gleick, president emeritus of the Pacific Institute for Studies in Development, Environment, and Security. “But it's unrelated to the cause of the fires and how to deal with the fires.”