Tropical Storm Hilary helps take California out of drought conditions, for now
AILSA CHANG, HOST:
If every cloud has a silver lining, the many clouds of Tropical Storm Hilary, which brought flooding, mudslides and destruction to Southern California and Nevada, also did bring some relief, at least from drought. You see, after a winter of atmospheric rivers and the first tropical storm to hit California in 84 years, almost the entire state is now out of drought conditions, which had grown severe in recent years. Unfortunately, this situation is probably only temporary.
Let's bring in Alex Hall now, a professor at the University of California, Los Angeles, and director of the school's Center for Climate Change. Welcome.
ALEX HALL: Thank you. It's great to be with you.
CHANG: Great to have you. OK, Alex, I want to start with the good news. Where does California exactly stand now in terms of drought after all of these different storms, all the rain and snow last winter?
HALL: Well, we had a spectacular series of storms last winter, and that alone replenished our water supplies and left us in a very good position. And then, in addition, we received this extra bonus in Southern California with this tropical storm. So we are officially out of drought in California, and we are in a pretty good position now as we wait to see what happens with our next wet season.
CHANG: And as we all know, water - I mean, it's a huge point of contention in the Southwest. There have been these long-standing battles over Colorado River rights. How much did all of these recent storms ease those challenges, at least for the time being?
HALL: Well, the really large amount of precipitation that we got during our last winter - that was a really big factor in making it a lot easier for California, especially, to agree to voluntary water cuts from the Colorado River system. That happened earlier this year. That really did make it a lot easier, and it made it easier for California to leave some of its allocation in Lakes Powell and Mead. The Colorado River system is still in crisis, but the situation there is not quite so dire as it was before.
CHANG: That said, what is California's ability to store all of the excess precipitation that the state has had recently?
HALL: California has a very robust system of water storage, especially the reservoirs lining the foothills of the Sierra Nevada. And in Northern California, there are very large reservoirs. And the system is really designed to capture the water that comes in from the precipitation associated with atmospheric rivers in the wintertime.
California does not have a great capacity to capture and store the water that comes from very rare event like this tropical cyclone that we had. It really impacted the southern part of the state, and the southern part of the state in particular just doesn't have the infrastructure to capture the water. It just came in too quickly, and the reservoirs are just not in the right place to capture water coming from a storm like that.
CHANG: So given that and given how extremely dry especially this region of California is, do you expect drought conditions to eventually return? And if so, when?
HALL: California is the land of extremes. It always has been. We have always had big, wet years and deep droughts. That's a hallmark of the hydroclimate in California. So we expect drought to return to the state. The challenge going forward is really to capture the water that does come in the wet years, especially in a changing climate where we expect there to be more precipitation in storms. We need to be in a better position to capture that extra water to get us through the inevitable droughts, which, by the way, will also intensify in a warming climate - probably already have intensified somewhat. We know that we will have dry years coming up, and we have to prepare for those.
CHANG: Alex Hall, climate scientist at UCLA, thank you so much for joining us today.
HALL: Thank you. It's been great to be with you. Transcript provided by NPR, Copyright NPR.
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