Preparing for unpredictable precipitation with David Feldman
One phone call can alter the trajectory of a person’s future. That’s exactly what happened to David Feldman, professor emeritus of urban planning & public policy and political science. While pursuing his Ph.D. in political science at the University of Missouri in the late ’70s – with a focus on political theory and public policy – Feldman earned a Presidential Management Fellowship. That recognition drew the attention of the director of the Water Resources Planning Program for the state of Missouri.
One life-changing call later led to an in-person meeting in the state’s capital, Jefferson City. Feldman was told his task would be to write a state water plan in collaboration with other states in the region. At the end of a lively and engaged job interview, Feldman confessed that he didn’t know anything about water. As he tells it, the director laughed and said, “No, no, no – you don’t understand. You come here and tell us what you know about policy, and we’ll teach you what you need to know about water.” And so began his path.
The director of Water UCI specializes in water resources management and policy, global climate change policy and ethics and environmental decisions. This episode of The UC Irvine Podcast is one of several focused on El Niño events. Feldman discusses how predicted precipitation will affect local and regional water supplies and addresses whether the infrastructure is prepared. He also shares what we’ve learned from past storms and what can be done to shore it up long-term.
“To Weather a Storm,” the music for this episode, was provided by Dan Lebowitz via the audio library in YouTube Studio.
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TRANSCRIPT
Cara Capuano/The UC Irvine Podcast:
From the University of California Irvine, I’m Cara Capuano. Thank you for listening to the UC Irvine Podcast. This episode is one of several focused on El Niño events. Our guest today is David Feldman, UC Irvine professor emeritus of urban planning & public policy and political science, and the director of Water UCI.
Water UCI is an interdisciplinary center in the School of Social Ecology that coordinates collaboration across UC Irvine’s schools, departments, and research centers to investigate questions around water science, technology, management, and policy. Professor Feldman specializes in water resources management and policy, global climate change policy, and ethics and environmental decisions. Professor Feldman, thank you for joining us today for The UC Irvine Podcast.
David Feldman:
Thank you for having me. It’s a real pleasure, Cara.
Capuano:
We’re having our conversation in the middle of October of 2026, and we’ve already seen uncharacteristic weather in Orange County. What stands out to you so far?
Feldman:
I think the thing that stands out most important to me is that we are in a water deficit period – a serious deficit, particularly in the Colorado River. And here we are on the verge of what we think may be a historic El Niño in terms of the possibility of precipitation.
So, there’s obviously a lot of anxiety and a lot of positive thought on the one hand – about the possibility of replenishing our reservoirs and our rivers and our groundwater basins – but also a lot of concern about how intense this El Niño event may be, especially in light of the fact that we just had a tropical storm, Rachel, which did some severe damage along the coast.
Capuano:
What is on the horizon?
Feldman:
We don’t know, but fortunately we do have people that are anticipating that we’re probably going to have a huge precipitation event in the Southwest, California more generally, and certainly here in Southern California. So, preparations are actually afoot to try to anticipate how much and what we can do to maybe harvest, store it, and reuse it rather than allowing all of it to go to the sea.
So, in terms of impacts on local and regional water supplies, I think on the whole, there’s a very positive outlook. We know that El Niño could, for example, boost the levels of water in Lakes Mead and Powell along the Colorado River, which the Southwest depends upon enormously. And in the case of Southern California, we’ll depend enormously on Lake Mead in particular – not only for water, but also for hydroelectric power. And if you don’t have water, you’re not going to have that. So that’s a positive. Right now, the reservoirs are at about 30% of capacity, so any El Niño effect that we can get that’s positive would definitely help that.
Looking more locally, in particular Orange County and also the Los Angeles metropolitan region, there’s some positive opportunities there. We know that the Orange County Water District, which depends heavily on the harvesting of water when it does rain, has been preparing to make sure it can capture as much rainwater as is possible to recharge our groundwater basin.
There was a rain cycle three years ago – 2023 – which allowed a large water harvest that resulted in the water district avoiding having to buy imported water, for example. And just to give you an illustration of what that might mean: in one cycle, the Orange County Water District can capture up to 26,000 acre-feet of water.
Now, people listening to this podcast have no idea what an acre-foot is and could probably care less. Let me simply say that it’s enough water to satisfy the needs of about 75,000 people for an entire year. So that’s a pretty significant gain if in fact we can capture and harvest that much water.
Something else to say about that: imported water costs money. So, by harvesting this water, the Orange County Water District could save the equivalent of some $26 million, and that’s $26 million that we as rate payers don’t have to pay. So, that’s one local benefit.
I’m going to turn to Los Angeles for just a moment. They kind of got a later start than Orange County did on water harvesting, but they’re doing it. They can capture about 83,000 acre-feet of water per year, which is equivalent to the needs of about 250,000 people for the course of a year. Much of that water is stored in the San Fernando Valley and elsewhere. So, these are definitely good things.
Capuano:
Thank you for interpreting what an acre-foot of water meant as far as how it supplies the citizenry. You mentioned preparation is afoot. What’s being done right now to prepare for these storms?
Feldman:
It’s very interesting. The state of California has actually been preparing to leverage surface and groundwater storage opportunities this coming winter to put the state in the best possible position to capture water, not just to capture it for water’s sake, but to capture it for when dry conditions return – which they inevitably will, probably next summer.
Efforts are underway under Governor Newsom’s water supply strategy to enhance groundwater recharge, which improves our water resiliency and security. It can also reduce flood vulnerability. The more water you can harvest, the less water you have to worry about that’s going to damage people’s homes and property. And the Department of Water Resources, which is the principal state agency responsible for initiating this water supply strategy, has been hosting a series of what are called “Recharge Readiness” webinars throughout the state, working with local communities to provide technical guidance to help them prepare for potential storms and how to harvest them. So that’s definitely a very positive event.
There’s also something called the State Water Project, which delivers water from Northern California to Southern California. This project was initiated way back in the 1960s under a previous Governor Brown, Pat Brown, and it was and remains probably the foremost water supply project here in California, a very pioneering effort.
There are efforts underway right now to maintain and inspect the system, to make sure that the State Water Project is ready for winter, to take advantage of opportunities to capture, store, and move water and also to maintain flexibility to respond to changing water supplies. The agencies served by the State Water Project serve some 27 million people. So, this is no small measure, and it is an incredibly important measure in terms of preparation.
I want to just say one thing about long-term preparation, going beyond these things that the Governor and the State Water Project and the California Department of Water Resources are doing. We still need to find more ways to store and use runoff. In urbanized areas especially, we have to make sure that when we capture storm water, we don’t disrupt local watershed processes and deny water to streams that might otherwise feed wetlands or creeks. And we also have to make sure that there are sufficient flows that go into receiving bodies so as not to disrupt ecosystem health in our estuaries and near ocean environments. So, there’s a delicate balance that needs to be performed in order to do this.
I’ll say lastly that storm water flows while positive on the whole, in terms of water supply, can carry high loads of sediment and silt. So, we have to figure out a way to remove and to reduce the sediment loads because this adds to the cost and the complexity of treatment. And if you’re going to harvest this water to use it, it has to be in a usable form.
The bottom line for me as a social scientist is that it’s important to engage local community groups who will be affected by these projects and who are likely to be paying for their operation.
Capuano:
You mentioned flooding earlier. Can our water infrastructure manage these potentially high levels of flow?
Feldman:
It’s a great question, and the answer is there are some doubts about the capacity of our system to handle these high flows. Let me give you some examples, mostly focused on local and also regional issues here in California.
Storm water and wastewater systems may be vulnerable to high flows, particularly during flooding events. I’ll use the example of Los Angeles. In Los Angeles, when you get a high rain event, water can seep into the ground and can infiltrate cracks in aging wastewater pipes. Those pipes can burst during heavy rains, or worse, in large wastewater treatment plants like the Hyperion plant – up near Santa Monica – they can overload those plants and potentially spill sewage into the ocean or back up sewage into communities. This has happened in the past, not from El Niño, but from other high flow events. Some 30 cities rely upon the Hyperion plant alone, and including the cities of Los Angeles, Beverly Hills, Culver City, West Hollywood.
So, we have to make sure that we maintain these infrastructural facilities, make sure that they can sustain these high flows, and make sure that they operate the way we’ve designed and built them so that they don’t inadvertently cause harm.
One of the things that’s interesting about California’s water situation today is that despite the fact that we’ve had a deficit in precipitation, our surface water reservoirs are actually currently above average in their storage. That’s good news, but it’s also bad news from the standpoint of additional flood flows. There’s just not a lot of places to put the extra water. So again, it gets back to an earlier point about longer term planning to make sure we have places to store water.
And there are other risks as well in terms of flooding. One is what we call “rain-on-snow flooding.” Now, meteorologists are anxious to predict when and where precipitation will come through El Niño. But until we’re actually certain, what we know is that with warmer storms and higher freezing levels, atmospheric rivers – and we see these frequently during El Niño events – might bring rain to elevations that would normally receive snow.
If that happens, the combined runoff can overwhelm downstream channels, and that can affect the welfare of highland communities here in California, such as communities in the Sierras or even in the San Gabriels and San Bernardino Mountains. And in addition, large reservoirs such as Shasta Reservoir or Oroville have to maintain flood control space in their reservoirs under federal guidelines. This is something that Washington D.C. determines, not Sacramento.
What that means is that reservoir operators have to reduce water early in the season, even as snow melt arrives ahead of schedule. These flows can’t be captured, and they won’t be available for drier months. So, balancing supply and harvesting on the one hand and averting floods on the other is a very tricky business when it comes to managing water infrastructure.
Capuano:
Sounds like a lot to think about. What have we learned from previous El Niño events? This isn’t our first time at this rodeo.
Feldman:
The good news is I think we’ve actually learned quite a bit. One of the biggest lessons is the need for proactive and early preparation. And by early preparation, I mean things like the pre-deployment of local emergency response and recovery resources.
A couple of weeks ago, the governor declared a state of emergency for El Niño, and I think a lot of people probably scratched their head and said, “But it’s not here yet. Why declare a state of emergency?” Well, this was actually very wise and very prudent because the governor’s decision allows us to think about ways of deploying resources for emergency response and recovery before they’re actually needed to give us time to plan for things.
For example, knowing what areas are likely vulnerable to mudslides – and in Southern California, as we know, that generally means burn areas – means that we can identify especially vulnerable foothills populations, peoples who maybe have a need for sandbagging, for emergency sheltering needs if they have to be evacuated, and of course – as we know from Tropical Storm Rachel – coastal beach fortifications.
In other words, basically focusing on ways we can pre-deploy resources before they’re actually needed: putting up berms on the shore, preparing to put up sandbags in canyon areas and so forth.
Give you an example right here in Orange County – two areas, Trabuco Canyon and also San Juan Creek. Already crews are working on the burn scars area, monitoring them and making sure that those areas can be fortified in the event of an El Niño event affecting those burn areas.
Something else we’re doing statewide – we are attending to flood infrastructure, the very infrastructure that I talked about a few moments ago. Already the Department of Water Resources has been inspecting and preparing some 1600 miles of levees within the state’s flood control plan, and they’ve been performing maintenance on key flood conveyance facilities, including bypasses, flood control structures to help ensure that they function as designed.
We’re not waiting for the rain to come before fixing these and maintaining these facilities. We’re doing it now. Kind of like you winterize your car? Well, here we’re winterizing our flood control structures.
Here in Orange County, the Orange County Water District is removing invasive plants for local creeks as part of the preparations to clear the waterways so that rainfall draining out of inland communities can flow to the ocean without backing up. We’re also assessing how quickly invasive and non-native species regrow after they’re cut. These are areas that are vulnerable to flooding and mudslides and they’re being inspected frequently and being maintained.
And then lastly, we were talking about the difficulty of predicting the weather. That’s not getting any easier, but one of the things that the California Department of Water Resources has been doing recently is using what are called “Forecast-Informed Reservoir Operations.” This is an approach that relies on long-term weather forecasting rather than fixed rules to make decisions about when to store and when to release water for the reservoirs.
Now, that’s a good plan, but there are still some legal and infrastructural barriers to overcome in this domain. Unfortunately, public policy hasn’t caught up with meteorological science, but at least we’re thinking ahead. How can we calibrate how much water to store and how much to release given long-term forecasts?
Capuano:
What are you doing right now to prepare for the predicted precipitation?
Feldman:
Two things. One is clearing brush from my backyard. And, secondly, preparing for interviews such as this, because I know once this event happens, there’s going to be a lot of interest in the local media and probably elsewhere about what we are doing in Southern California – so, trying to keep up with as much of what’s going on as possible.
Capuano:
What haven’t we discussed today that you wanted to share in this conversation?
Feldman:
There is a big movement afoot in the water science and policy community called “Nature-based Solutions.” And basically, this is predicated on the idea that nature knows best how to manage floods, and nature knows best how to store water.
For centuries, we’ve filled in wetlands and thus denying to ourselves and the environment the benefits of wetlands as flood control mechanisms that are created by nature. At the same time, we forget the fact that rivers, before they were channelized and straightened and covered with concrete, used to flow quite naturally and used to percolate water down into groundwater basins.
Basically, Nature-based Solutions suggests let’s return to that whenever possible. Let’s rely on things like wetlands, parks, rain gardens, permeable pavements, the replacement of landscaping with more natural, native vegetation, and similar techniques to collect and to utilize captured rainfall. Good ideas! It’s going to take time to implement.
The good news is California has started to move in this direction, both locally and statewide. Locally, we see a lot of communities – we certainly see it here in Orange County – that are trying to build new communities in ways that are nature-based in terms of harvesting stormwater for plants and also for reuse of water. Los Angeles is doing the same thing.
A little north of us in the Central Valley, there is a Flood Protection Board, which four years ago adopted a plan that, and I quote, “Moves away from practices that constrain nature and toward strategies that work with nature to control flooding.” Not relying totally on levees, but what about levee setbacks? What about floodplain storage? What about buying land outright to use as conservation easements? These are things that can return a habitat to ways they were maybe a hundred or more years ago. That will cost money – some $25 billion is being spent or will be spent over the next 30 years to prepare against these catastrophic floods through nature-based solutions.
So, these are things that are really good developments. And I might mention that nature-based solutions to manage flooding are being adopted elsewhere as well.
Capuano:
Thank you so much for joining us today, Professor Feldman.
Feldman:
You’re welcome.
Capuano:
I’m Cara Capuano. Thank you for listening to our conversation. The UC Irvine Podcast is a production of Strategic Communications and Public Affairs at the University of California, Irvine. This episode is one of several focused on El Niño events. You can find others wherever you listen to podcasts. For the latest UC Irvine news, please visit news.uci.edu.