Deadly and costly storms hit California again

Transcript

MICHEL MARTIN, HOST:

Californians are on flood alert yet again today. The parade of heavy rainstorms is continuing, and evacuations have been ordered near Monterey on the Central Coast. Nineteen people have died across the state, and the damages are likely to hit hundreds of millions of dollars. We were wondering if there's a lesson to be learned from these storms and if there is something California and other states can do to be better prepared, especially as the climate changes. Lauren Sommer from NPR's Climate Desk is here to answer that, and she's with us now. Lauren, thanks so much for joining us.

LAUREN SOMMER, BYLINE: Yeah. Thanks.

MARTIN: So right now, the problem is just too much water. But paradoxically, California is still in a multiyear drought. Have the storms helped with that?

SOMMER: The drought has improved. You know, new federal data shows that the overall severity of the drought is less, but the entire state is still in some form of drought. Reservoirs are filling up. But after several years of these historically dry conditions, they started out extremely low.

MARTIN: So is there something that California could be doing to save some of this heavy rainfall and help alleviate the drought? I think it's something that's on everybody's mind.

SOMMER: Right. Exactly. Yeah. And there is a new approach that is being tried out. Typically, reservoirs in the West have to release water in the winter because they're required to have empty space. That way, you know, if a big storm hits, the dams aren't overwhelmed and possibly fail. But that hasn't worked out great when there weren't any big storms because they lost water they didn't need to. So now there are two reservoirs that are using the weather forecast instead of those automatic rolls. And they only will empty out if more storms are coming. Marty Ralph, who studies reservoirs at UC San Diego's Scripps Institution of Oceanography, says, you know, this could make a difference this year.

MARTY RALPH: We have to use every drop of water that much more effectively. There's not much to spare. Climate change is a thing that's evolving the extremes here.

MARTIN: Well, to that point, should California expect to see more of this kind of weather with climate change? How much more extreme are the extremes going to get?

SOMMER: The phrase people are using is weather whiplash - so longer, more intense dry periods and then more extreme storms. You know, that's something climate scientists like Daniel Swain of UCLA expect to see more of as things get hotter because warmer air can hold more moisture so the rainfall gets more intense, he says.

DANIEL SWAIN: The degree to which climate change has made this storm sequence or storm sequences like it wetter in California is anywhere from about 5% on the low end to 15% more intense on the high end. And that may not sound like a lot, but that can result in large increases in the relative amount of runoff we see during these events.

SOMMER: And as bad as this storm has seemed, it's actually not the worst-case scenario. He says weather records show even more extreme storms are very possible with climate change.

MARTIN: So if California needs to prepare for something even worse, does your reporting indicate what it should be focusing on to reduce the damage and the destruction from flooding?

SOMMER: Yeah. The key thing to focus on is our built environment. You know, we tend to treat rivers like they never change, right? We build right up to the river front. But that hems them in, and it gives floodwaters nowhere to go. So there is a movement now to give rivers more room to, you know, move the levees back, restore the natural space around them. That's tough to do, of course, because it involves buying out people's properties. But, you know, the momentum is growing because people are realizing if the weather is getting more dynamic, our environment needs to build in that kind of leeway, too.

MARTIN: That's Lauren Sommer from NPR's Climate Desk. Lauren, thank you so much.

SOMMER: Yeah. Thank you. Transcript provided by NPR, Copyright NPR.