Last month's deadly wildfires in California destroyed thousands of homes, killed at least 29 people,

and will likely cost hundreds of billions of dollars.

President Trump has repeatedly claimed that state officials made this disaster worse by how they manage the state's complex water system.

William Brangham looks at those allegations and the realities

of water management in the nation's most populous state.

While fires were still burning in Southern California and crews were trying to save lives

and property, then President-elect Trump took aim at California's Democratic governor, Gavin Newsom.

It's very sad because I've been trying to get Gavin Newsom to allow water to come.

You'd have tremendous water up there. They sent it out to the Pacific.

And after he took office, he kept coming back to how California officials manage their water,

blaming them from making the fires worse.

We're demanding that they turn the valve back toward Los Angeles.

Millions of gallons of water are waiting to be poured down a fire that could have been put out if they let the water flow.

But is it true that more water from Northern California could have helped Los Angeles? There's no truth to that. Donald Trump has a strange fixation with California water policy.

He has for many, many years. He comes out here. He talks about some imaginary valve or some imaginary

faucet that he or someone else could turn to increase the amount of water that flows from

Northern California

to Southern California. It's sort of an odd fixation.

Let's start with some context. California has one of the largest and most complex water systems

in the world. It's responsible for delivering drinking water to almost 40 million people

and irrigating farms that grow three-quarters of the nation's

fruits and nuts.

...