AUSTIN (KXAN) – California has seen a relentless series of storms brought on by an atmospheric river set up. Much of the state saw feet of rain while the Sierra Nevada Mountains picked up over 10 feet of snow in some areas.
Before this series of storms, California was struggling to even get a drop of rain. Prolonged years of dry conditions has placed them in a mega-drought with lakes and reservoirs reaching critically low levels.
Meteorologist Sean Kelly spoke with Assistant Professor Geeta Persad, Department of Geological Sciences with the University of Texas to discuss how it is possible that California is still in a drought despite weeks of flooding rain and what it would take to get them out of a drought.
Below is a transcript of their conversation:
Sean Kelly, KXAN News: I know some areas of California picked up feet of rain. Is it enough to get them out of a drought?
Assistant Professor Geeta Persad, University of Texas: So one of the really good things that we’ve seen with this set of atmospheric river events that it has been bringing a lot of water to California, that they’ve been helping build up the state snowpack. And for a place like California, where the rain, the water is really variable. So they get a lot of their rainfall in the winter. And then they really need to use it during the summer. And so you need things like snowpack that basically build up inertia in your system, they act as kind of a natural storage system. And so the fact that we’re getting a lot of snowfall in these systems, building up a lot of snowpack is going to be really beneficial going forward.
But the reality is that California over the last decade essentially has really built up a debt when it comes to its water use. So if you think about a bank account, California had all of this water stored in its groundwater aquifers. And as the drought dragged on over the last decade or so they started, you know, taking withdrawals out of that groundwater bag that they had. And over time, they’ve basically gotten themselves into the red with their groundwater aquifers. And so now, that other form of natural storage that they had, is really, really drawn down. So it’s gonna take a long time for that to rebuild. And the storms that we’re seeing right now, most of that water is flowing out into the ocean, rather than going into the aquifers because of how extreme that rainfall is, and, and how intense it is. So we’re really not looking at, we’re looking at a situation that is certainly beneficial in the short term, at least in terms of the snowpack, but it’s really not going to be enough because of the form that it’s coming in to, you know, get California back out of the red.
Kelly: Tell me a little bit about flash flooding and how that water really can’t be used, because it could be maybe contaminated a little bit.
Persad: So when you get really intense rainfall and you get flash flooding, some of the damage that we’ve seen some of the loss of life, from mudslides, those are all issues that start to arise. So even if that was beneficial for water use, we would have all of these other downsides that mean that it’s really you know, not optimal when we get our water in that form. Now, when we think about using, say storm-water, for, you know, capturing storm-water and reusing it, that is really problematic when that water is contaminated and full of, you know, debris that it’s picked up along the way because it came in this really intense way. So for most places, when the storm water is coming in those really intense flash flood kinds of events. They actually can’t store it and reuse it for those purposes.
Kelly: Tell us how these atmospheric rivers can be too much of a good thing?
Persad: And so the problem right now is that what we’re basically seeing is that these atmospheric river events are sort of like pointing a firehose at that bathtub. So you’ve got your reservoirs, you’ve got your groundwater aquifers, but they’re not built to store water in this magnitude and at this rate. And so what we’re seeing is that, you know, most of that water is sort of blowing out over the edges of that proverbial bathtub. Right? So it’s flowing out into the ocean. And that means that it’s not going to be available when people need it during the summer months when things are hot and dry in California
Kelly: What would it take to get them out of this drought, this mega drought that they’re in? Would it be years of rain? Would it be more spaced out rain events.
Persad: One of the things that we know with climate change is that the intensity of these rainfall events is likely to accelerate into the future. And we also know that the precipitation that comes in California is going to be less and less in the form of that snow that’s so helpful for building up the natural snowpack reservoir, and more in the form of these rainfall events that just flood everything and flow out into the ocean. And so that really means that California is going to have to get a lot more strategic about how it uses stormwater to recharge groundwater, more strategic about when and where water use is happening. Because these situations, these conditions are only going to continue and intensify going into the future.