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Groundwater: ‘Go Deep or Go Dry’ is Unsustainable

Debra Perrone, Assistant Professor UC Santa Barbara, discusses the dwindling groundwater supply affecting 12 million US wells caused by global warming and over-consumption. The world relies on groundwater, which is getting harder and harder to find. With groundwater close to the surface vanishing, well-drillers are forced to turn to deep drilling for corporate, agricultural, and domestic water needs. But going deep this way is far more expensive and increasingly yields contaminated water.

Please note: For seasons 1 and 2, we were known as “Let’s Talk About Water,” so you may hear that title in this episode. Don’t worry, it’s still us!

Guest Bios

Debra PerroneDebra Perrone

Debra Perrone is an Assistant Professor of UCSB’s Environmental Studies Program. Deb integrates research methods from engineering, physical science, policy science, and law to inform water sustainability and public policy; she uses a wide-spectrum of outlets to disseminate her research, including peer-reviewed journals, policy briefs, and interactive- online dashboards. In 2019, Debra co-authored an undergraduate textbook, Water Resources: Science and Society, which provides a foundation in water science and policy and highlights the challenges and opportunities surrounding our global water resources.

Video

Deb’s lecture at the Global Institute for Water Security Distinguished Lecture Series

Further Reading

Socials

Twitter

Full Transcript

Debra Perrone:
We identify 12 million groundwater wells. We are showing that there are problems with groundwater. There is groundwater wells that are running dry and I think that we have an opportunity here to really put numbers to anecdotal evidence and inspire people to be passionate about this resource that I’m obviously really passionate about to mobilize people, to make change.

Jay Famiglietti:
Hi, everybody. Welcome back to Let’s Talk About Water. I’m your host, Jay Famiglietti. Almost since human beings first became recognizable as a species, we relied on digging wells to tap into groundwater. In fact, archeologists tell us that wells are among the oldest human-made structures that they’ve ever discovered. However, what worked well 30,000 years ago is, well, working less well today. Just a little hydrology humor there. Well, okay, not joking now, in many places around the world, groundwater supplies are being over-exploited. This over-exploitation, coupled with climate change, means that groundwater supplies are being stretched to their limits, while at the same time, more and more wells are now sunk deeper and deeper to tap into dwindling supplies. That sounds like the definition of unsustainable to me.

Jay Famiglietti:
Groundwater depletion has been the focus of much of the latter part of my career and as I begin to think more and more about playing shuffleboard in Florida every day rather than my next research paper, I get pretty excited when I see younger scholars doing breakthrough research that really has the potential to move the needle in global water security, scholars like Debra Perrone, who explores the interrelationships among groundwater, its quantity, its quality, all those wells that are being drilled deeper and deeper in what it all means for sustainability in society. Deb is an assistant professor in the environmental studies program at the University of California, Santa Barbara. She’s also a fellow of Stanford University’s Water in the West program. Deb, thanks so much for joining us today.

Debra Perrone:
Thank you for the invitation to talk with you today.

Jay Famiglietti:
We should probably start off with the importance of groundwater. Can you share with us how we use it around the world?

Debra Perrone:
Yes. Groundwater is really important. It’s important for water withdrawn for irrigation. It’s important for public supply, domestic supply. 40% of the water that we use globally for irrigation comes from groundwater, and more than 50% of the water that’s withdrawn for household and drinking water purposes comes from groundwater resources. Groundwater is particularly important in places where we are seeing drought. There’s a number of reasons for this. It’s more resilient to climate impact. There’s a large storage of groundwater underneath our feet and it allows us to access it in places where we have arid climates and places where we’re not able to be connected to large public supply systems. It allows us to live in places that we probably otherwise would not be able to live and it allows us to produce food in places that are not necessarily close to rivers and other surface water resources.

Jay Famiglietti:
Pretty amazing stuff. When I think about some of our desert cities around the world and the United States, I always think and worry about Phoenix. Without that groundwater, Phoenix wouldn’t be there, I think a lot of our other desert cities wouldn’t be there. Without sustaining that groundwater supply, I feel like these desert cities are really at risk, but what do you think about that?

Debra Perrone:
Tricky question. I think there are places where we are using a lot of groundwater. There’s a heavy reliance on it. We’re seeing declining groundwater levels. We’re seeing the impact from depletion. I do think that there’s a lot of different technological developments that we’re making and I also see a lot of progress in policies and law to help us really recognize that this is an important resource and recognize that we need to make progress in how we manage those resources. I think that there are places in the world that we are overusing groundwater. There’s no doubt about that. Groundwater depletion is happening, it’s been documented. There are also a number of places where we are using groundwater sustainably and there are a number of examples of places where we are managing groundwater in a sustainable way, looking out for the future.

Debra Perrone:
I should point out, though, that there are places where we have a really big reliance on groundwater. That’s specifically in the Western United States. The Western United States, there are some areas that rely almost 100% on self-supply domestic withdrawals and this is one of the reasons why I’m really fascinated in groundwater wells and the impact from declining water levels. We also know that there are some cities that rely almost entirely on groundwater, and in some regions, there are places that rely nearly fully on groundwater for irrigation, and so it’s a really important resource. It hits both people, humans, ecosystems, it also hits economies, and as you know, it’s fundamental to social/economical/cultural perspectives and how that plays a role in our management.

Jay Famiglietti:
One of the big challenges and you talk about it and I talk about it and the UN talks about it, it’s underfoot, we can’t see it. You, I, so many of our colleagues talk about the need to make the invisible visible. Can you tell us what that means to you?

Debra Perrone:
I like to start the story by talking about my road to groundwater. Prior to moving to California in 2014, I wasn’t really interested in groundwater. Most of my work on water scarcity focused on rivers. When I moved here in 2014, California was in the middle of this really big drought. The news was covering the drought, it was covering groundwater depletion. We had investigative reporters highlighting that households were losing access to water because of depletion. This was mind-blowing to me. We’re in one of the richest countries in the world. We’re in California, which is a state, by some accounts, is one of the top 10 largest economies in the world, and yet people were losing access to water in their house, and so this really highlighted to me this contrast in many ways with surface water and groundwater.

Debra Perrone:
I was new to groundwater and what I realized was that it wasn’t just this resource that was invisible. It was everything about groundwater that was invisible. It’s the groundwater wells. The infrastructure is modest. Groundwater wells, they’re small, they’re distributed, they’re lost among the landscapes, and in contrast our surface water infrastructure is big, it’s sexy, it’s eye-catching. We have large reservoirs that people use for recreation, we have dams, hydroelectricity facilities, canals, and it’s just in such contrast to groundwater and groundwater’s infrastructure.

Jay Famiglietti:
When you gave your presentation up at the Global Institute for Water Security, the other day I was taken by, there was a cutaway and had maybe a woman on top and it had a well and then the falling water table. You know the one I’m talking about? Ideally, we’ll be able to link to this on our website. That would be nice, so people can see what we’re talking about. It seemed like something that wasn’t really easy to make. So, it takes work to make the invisible visible?

Debra Perrone:
It does take work. It takes a lot of thinking through the processes to make sure that I’m not only capturing what’s correct scientifically, but also simplified in a way that I can communicate this really complex topic to the public. I have to admit that a lot of the material that I put forward is actually inspired by the students that I teach. It’s inspired by how do I communicate something that I know is really important that I am super passionate about, and I want to get them excited about it. How do I communicate something that’s complex, but actually fundamental to society so that I could get them pulled into groundwater, get them excited about it, get them passionate about it, and then reveal the complexities and all the struggles in communicating it? So, I have to give a lot of the credit to the students that I’m working with.

Jay Famiglietti:
Well, they were super impressive graphics, so congratulations to your students and congratulations to you, too, because I think they really tell a pretty nice story. Yeah, I mean, the whole part about seeing the connections between the surface water and the groundwater and the water table falling underground, you have to combat the underground river theory of people paddling around in canoes underground, so I thought that those were particularly nice.

Jay Famiglietti:
I want to continue on this theme of making the invisible visible and I want to talk about this monster dataset of the groundwater wells that you put together in the United States, which is something that I don’t think has been done before, and by that, I mean, you really focused on characteristics like well location, the dates when the wells were drilled and completed, how deep they are, so that must’ve been a bear to pull off. I think I heard you say it took years to put together. How are you able to pull it off?

Debra Perrone:
This was, again, in the middle of California’s drought. I started working with Scott Jasechko and he was really fascinated by these big data projects and I was really fascinated by trying to figure out whether or not the anecdotal information that we were getting from California, wells going dry, people drilling deeper wells was happening in California and beyond or was it just something that was in California, and so that’s the inspiration behind it, to be honest, California investigative reporters showing that people’s wells were being impacted.

Debra Perrone:
It did take five years to put together, so this was not something that we just whipped up. One of the reasons why it took so long was because in the United States, water quantity is mostly the matter of state law, and so to break that down into layperson language, what that means is that each state collects data differently and we needed to piece all the different datasets together, and unfortunately, there’s not really a national standard and how people collect groundwater well reports or how that information is actually shared with the public, and so it took a bit of time to put together.

Jay Famiglietti:
Yeah, I’ll bet. I mean, I can tell. Doesn’t it have something like 12 million wells in it?

Debra Perrone:
It does.

Jay Famiglietti:
That’s a big number, so that’s not the kind of thing you’re going to be doing manually, right? You’ve got this great dataset and you’re starting to find things, and importantly, people’s wells are going dry. Is that happening a lot?

Debra Perrone:
Well, we focused that study on the Western 17, mostly because we were interested in the impact of the drought on people’s groundwater wells, and we did see that California is not the only state that, based on observational information, was showing that groundwater wells were drying. Now, some of these wells were constructed back in 1950, and so perhaps not as surprising that some of the wells were actually running dry, but we are seeing it in other places besides California. We’re seeing it in parts of the Southern High Plains, which is another really important aquifer in the United States.

Debra Perrone:
What we found is that a lot of the dry wells were clustered in agricultural areas, so areas like the Central Valley and many parts of the Southern High Plains, and again, this was not surprising because rural areas bear the brunt of groundwater depletion. We’re seeing this quite often. They have a hard time connecting to public supply systems just because there’s not necessarily enough people to put together a public supply system, and so it’s rural communities that are really relying on these domestic groundwater wells and groundwater wells are expensive to construct. The data that we found is showing that groundwater wells for domestic purposes can cost tens of thousands of dollars.

Jay Famiglietti:
Well, let’s talk about that a little bit. You had a graphic in your presentation, and again, our listeners will be able to find this presentation because we recorded it, so we’ll have a link to it on our website, but you had a graphic on the price of domestic wells. I guess it had to do with probably the depths of domestic wells and municipal wells and agricultural wells and it went from tens of thousands up to like over a million dollars.

Debra Perrone:
Yes, and so this was information that we got from newspapers, so again, this hits on, on water data and big data and the ability to actually access that data. We’re not necessarily collecting information about how much groundwater wells cost people, and so you have to go to these alternative sources to get information on how much a groundwater well costs. This is the number that people were reporting when they were being interviewed by investigative reporters.

Jay Famiglietti:
Yeah. I could be the one behind the $1.2 million, by the way. I was out in the middle of the Central Valley talking to a well driller and he said he was going down about, in the region where he was, average water table depth, I think it was something like 2200 to 2500 feet, and so he just said, “Okay, for me, for my company, a well that deep is a million dollars.” We had this same conversation, like, “Whoa, who can really afford that?” It wasn’t clear. I mean, we were on a farm, but I don’t know if it was a big farm or a small farm. We were just talking about the depth of the well and the cost and he said, “This depth range, 2200 to 2500 feet, we’re talking about a million dollars, and if we want it to be earthquake-proof and maybe subsidence-resistant, we’re talking about $1.2 million.”

Debra Perrone:
So, what I’m impressed about with the work that you’re doing is that, you know me, I’ll just say these things in my talks, right? I show the GRACE stand and I’ll say, “Wow, wells are going dry and the ground is subsiding,” and I’m not trying to quantify it in my own research. You are really putting some meat behind that. But I want to pursue the wells going dry thing and I’m worried about the future. Right, wells go dry for a lot of different reasons, but mainly as you show in some of your graphics, the water table is dropping and it drops below the bottom of the well, and so the well doesn’t access the water anymore. What is your expectation, or what have you shown or found in your research about how these numbers are going to increase in the future? What’s the likelihood that more and more of wells are going to go dry? How many numbers or research into that?

Debra Perrone:
I’ve not done projections, but we do know that in some places, groundwater depletion is occurring, and without good management, it’s likely to continue to occur, and so I wouldn’t be surprised in places where we’re not managing declining water levels if more and more groundwater wells are going to go dry. I like to think about things in terms of water scarcity. For me, a well running dry is one of the most pronounced manifestations of water scarcity. Somebody’s losing access to water that’s impacting either their ability to irrigate land, so impacting their ability to produce agricultural products, but also impacting the ability of people to exercise their right to withdrawal groundwater, and so there’s so many different components here. There’s access to drinking water, water for agricultural production, but then also this idea that dry wells are impacting somebody’s right.

Jay Famiglietti:
Yeah, the access thing is really, really a huge concern, and the example that I give when I give presentations or to elaborate on this point a little bit is that you may have a farmworker who lives close to the farm where they’re working and they have their own private domestic well and that well runs dry and they don’t have the money to dig the deeper well and they’re kind of stuck because it’s the very place where they work that has the deeper well that’s using a lot of groundwater and is the reason why they don’t have access to groundwater, so it’s a huge problem. We’ve been talking about falling water tables and wells going dry. What’s the source of this problem? Who is behind it? Is it people? Is it cities? Is it agriculture? What do the numbers look like?

Debra Perrone:
I think it really depends on where you are and the local context. I think this is something that people often point out about groundwater is that it’s a very local resource, but at the same time, we also know that our aquifers are regional in scale, and so in places like the Central Valley and the High Plains, the bigger water users tend to be agricultural pumpers, but then there’s other aquifers that the biggest water users are actually public supply and domestic well owners, and so there’s not really a broad brush to paint, and that’s actually one of the reasons why I really liked studying groundwater is because it looks different across the United States, across the world.

Jay Famiglietti:
We’ve been talking about, and you’ve been studying, the unsustainability of drilling deeper and deeper wells, but what’s to keep people from drilling more wells? I mean, why can’t we just go deeper and deeper?

Debra Perrone:
Well, we think that drilling deeper is unsustainable for four reasons, one of which we’ve talked about already, so that’s the cost, right? Not everybody can afford a brand new well, let alone a deeper groundwater well.

The second reason is because of the hydrogeology. I like to point out often the Southern High Plains, where folks there are actually hitting a bottom, they’re hitting the bottom of the aquifer where below that, they’re not actually going to be able to get good yields, so they can pump their groundwater up to the surface, but they’re not going to get a lot of water coming to the surface.

Debra Perrone:
That area is also interesting because it highlights the third reason why drilling deeper is unsustainable, and that’s because at some point, folks are going to hit brackish, the saline water. Deeper water tends to be saltier, and so that water may not be usable unless we treat it.

The last reason really hits this water-energy nexus. When we have declining water levels, we need more energy to pull the water to the surface. When we have deeper wells, we often get a deeper water level in the well, and so that also requires more energy to lift the water to the surface.

Jay Famiglietti:
That leads directly into the solutions part of what I’d like to talk about, people digging deeper and deeper wells. So much of what I saw when I was in California was the search for new supply rather than a reduction of demand and you’ve spent some time thinking about that. What are your thoughts on that?

Debra Perrone:
I have a lot of thoughts on that. As a trained engineer, I love the idea of technical solutions. I think they’re really important. One of the specific ones that I’ve studied is Managed Aquifer Recharge. There’s a place for that and I think that’s really important. One of the biggest problems, though, with groundwater recharge projects is that you need to have water in order to have a groundwater recharge project. You either need that water from recycled water, reclaimed water, so sources that we often get into your larger cities or excess surface water, and in reality, during drought, you’re probably not going to have that excess surface water, so Managed Aquifer Recharge only gets you so far and it’s not necessarily a good solution when you have a really long drought.

Debra Perrone:
The other part of my research focuses on demand-side management: What opportunities are there for policy and law to reduce impacts of pumping by reducing people’s allocations? Specifically, we focus on groundwater withdrawal permitting for new pumping and the reason for that is because we’re interested in finding ways to stop depletion before it happens.

Jay Famiglietti:
I like the proactive aspect of that. One of the things that was really clear, maybe this was happening before you actually moved to California, but looking at the number of new well licenses, not necessarily permits, but basically just permission to go dig a well, that number during the drought, just skyrocketing, so putting the brakes on that and giving more consideration to how much water is actually there and how it’s going to be sustained is super important, especially as different regions around the world start to undertake different groundwater sustainability plans. Now, you’ve talked about this Western Water Dashboard and you showed that a little bit in your presentation. Can you tell us about that?

Debra Perrone:
Yes. The Western Water Dashboard is an interactive online experience where you could go and learn about how the different Southwestern states are managing new groundwater withdrawals. The ultimate plan is to extend that to the entire West, so looking at all 17 Western states. The whole purpose of the Western Water Dashboard is to promote policymakers, people from the public to understand what’s happening in their state, but also in the neighboring states and elsewhere in the Southwest. The idea is focused on promoting user interaction with material that would otherwise be really complex and hard to understand and really focused on making the person who’s interacting with that data excited, making it a fun experience to learn about groundwater management.

Jay Famiglietti:
I’m excited. I want to go check it out. No, I think that’s really great to make those data accessible and in usable formats and make it available to water managers, stakeholders, decision-makers, and to the general public I think is really important, so that leads me to my question about science communication. How are you reaching out? Are you trying to take any trips to Sacramento or are you going to Washington DC? I mean, are you talking to stakeholders? Have you tried to tackle that yet?

Debra Perrone:
I’m very interested in science communication. I’m mostly focused on the side of how to communicate observational data to the public and really highlighted the scientific results component of it. I have not gone and spoken to my policymakers yet. I do work pretty closely with the different state managers for groundwater, just inherent in the project that we’re doing on Western water law, and that’s been really enlightening, really fun to learn all of the institutional knowledge that these water managers have.

Jay Famiglietti:
Yeah, I think it’s really important. It’s kind of an unusual step, but I think important, especially for people like you and like me when I lived in California. You’re really there in the crosshairs of climate change and drought and disappear in groundwater and some years with no snow and really, just limited water availability, and so having those connections and starting to talk to some of the water managers, having them understand that you can help them and you can expand their workforce and you can help train people that are eventually going to come and work with them I think is super important.

Jay Famiglietti:
On the DC and Sacramento stuff, I just want to say it’s important, but it can wait. I think as a young scientist, I think it’s important to do your work in build your reputation and sort of a recurring theme in science communication is that there’s not a lot of reward in your early career years for it and that is something that actually needs to change has been the topic of other conversations we’ve had on this podcast. Now, I’ve heard you say that you are optimistic and that people are going to come to grips with the problems that we have today with groundwater. You are optimistic about the future of groundwater management. Is that accurate? I’m just telling you in advance that I’m not.

Debra Perrone:
It is accurate. I am trying to stay optimistic. I think one of the reasons why I’m optimistic is because we’re getting evidence that can help mobilize change. I want to point out something that Ingrid Waldron said in one of your previous podcasts. She talks about the importance of evidence and the importance of evidence mobilizing change and we identify 12 million groundwater wells. That’s a lot of evidence. We are showing that there are problems with groundwater. There is groundwater wells that are running dry and I think that we have an opportunity here to really put numbers to anecdotal evidence and inspire people to be passionate about this resource that I’m obviously really passionate about to mobilize people, to make change.

Jay Famiglietti:
Well, I think that’s a great place to wrap it up, Deb. Debra Perrone is an assistant professor in the Environmental Studies program at the University of California, Santa Barbara. She’s also a fellow of Stanford’s Water in the West program and she’s co-author of a book called Water Resouces: Science and Society with George Hornberger. You can learn more about Deb at her website, debraperrone.weebly.com. You can catch up with her work on groundwater permitting and the Western Water Dashboard at groundwater.stanford.edu. You can follow the work she and her colleagues are doing at Stanford on Twitter. That’s @waterinthewest. Thanks again, Deb, for joining us.

Debra Perrone:
Thank you.

Jay Famiglietti:
Well, that’s it for another episode of Let’s Talk About Water reproduced by the Global Institute for Water Security at the University of Saskatchewan and The Walrus Lab. I’m your host, Jay Famiglietti. Thanks to the Let’s Talk About Water team who helped put the show together, including Mark Ferguson, Laura McFarlan, Amy Hergott, Jesse Witow, Shawn Ahmed, and our producer, Sean Prpick, and as always special, thanks to Linda Lilienfeld. Check out our next show on November 18th when we’ll be talking with Peter Gleick about the future of America’s waters under the next administration, but why don’t you make it easy on yourself and subscribe now to Let’s Talk About Water and then set an alert so you’ll know the moment we hatch a fresh podcast? We’re also really easy to find because we’re on Apple Podcasts, Spotify, Stitcher, and many other quality podcasting platforms. You can also stream us on Facebook at Let’s Talk about Water Podcast, or follow us on Twitter at @ltawpodcast. See you next time!