WATER POLITICS

I was mesmerized listening to John Cherry talk about groundwater, so absorbed that I didn’t notice that two hours had gone by. With lucid clarity, he laid bare the massive groundwater crisis engulfing us.

Cherry speaks from a place of gravitas. He’s won the Stockholm Water Prize, known as the ‘Nobel’ of water, which is awarded in conjunction with the Royal Swedish Academy of Sciences, the same institution behind the Nobel Prize itself. He wrote the seminal Groundwater textbook that shaped our modern understanding of groundwater hydrology. He essentially pioneered the entire field of groundwater contamination.

In our conversation, he poignantly pointed out that the water crisis is really a crisis of groundwater. 99% of liquid freshwater is groundwater, and groundwater supplies 40% of our food, and 70% of irrigation, but many major aquifers are already overdrawn. The Ogallala, which grows a sixth of the world’s grain, could be largely unusable within decades. Once natural buffers against drought, aquifers are now drained, leaving regions like California, Spain, São Paulo, and Cape Town vulnerable to even short dry spells.

He noted that the Green Revolution of the mid 20th century wasn’t just about using synthetic chemicals and high-yield seeds to produce more food, it was also withdrawing more groundwater. Cheap pumps fueled massive irrigation, temporarily boosting yields but eroding soils and depleting aquifers. Today, exhausted soils and collapsing aquifers are twin legacies of that mid-century surge.

Global “virtual water” trade has been hiding the growing groundwater crisis. Wealthy nations import crops grown with disappearing groundwater, from Peruvian blueberries to Arizona alfalfa for Saudi Arabia. Far from increasing food security, globalization has made local water crises a global problem.

There was so much rich material in our interview that I couldn’t squeeze it all into one written article (Substack has length limits), so I’ve split this into two parts. Part II will go further into the crisis, and also explore solutions – regenerative agriculture, rainfall harvesting and managed aquifer recharge. The audio podcast remains one complete episode.

Here is a lightly edited, abridged version of the interview : Part I

Alpha: Lets give you a little bit of an intro. You’ve written a very widely regarded textbook on groundwater, and you were a pioneer of contaminant groundwater.

John: Yeah, I wrote that book Groundwater with a colleague, published in 1979. There weren’t any other modern books on the market, so it became a widely used book for many decades. It’s on the Groundwater Project website and it’s one of our most highly downloaded books, even though it’s very old.

Alpha: Yeah, it’s very readable. At some point you began exploring the bigger picture idea of why groundwater is so important to the world.

John: Yeah, I started the Groundwater Project as a follow-up to the textbook by Al Freeze and myself. The idea was to just publish a few books on the web and then it grew and grew, and that got me into looking at the bigger picture. Bigger picture lectures are what I’ve been giving for the last four or five years. First I was talking about the bigger picture of the state of groundwater science, and now it’s really about the bigger picture of groundwater in the world and how it’s kind of ignored and unappreciated and mostly pictured incorrectly.

Alpha: You’ve won some of water’s biggest prizes. The Lee Kuan Yew Prize and then the Stockholm Water Prize.

John: I won the Lee Kuan Yew Prize of Singapore in 2016, and then the Stockholm Water Prize in 2020, rather late in my career. But it kind of caused me then to want to develop responses to broader questions. Really, it was the Lee Kuan Yew Water Prize when the interviewers would ask me, “Why is groundwater important?” The technical things for which I won the prize were entirely irrelevant in terms of the big picture. So I realized I had to develop responses to the question of why groundwater is important.

Alpha: I think for a lot of people, when they first hear about groundwater, they don’t really realize they should have any significant thoughts about. It’s just this water deep underground which we don’t see. And yet, I think you’re saying there’s actually this whole groundwater crisis that’s looming that has repercussions for many things—from our food to our water systems. Really key to human society.

John: Yeah, and it’s now recognized that there’s a global water crisis. The World Bank and UNESCO and all the global organizations pay lip service to that, that there’s a global water crisis. But they never get to the point of what’s the nature of the crisis. It’s primarily a groundwater crisis because groundwater makes up 99% of all liquid fresh water. The number you see in the textbooks is always less than that because they include ice. But when you take ice out of it, it not being a liquid, groundwater is 99% of all liquid water. And most of the time, all of the water that flows in streams and rivers is groundwater. It’s called base flow. All wetlands are fed by groundwater, and most ecology that’s water-related has a groundwater feed. People just don’t recognize that because you don’t see it.

About half the people in the world drink groundwater to some degree or another. And 40% of the food these days is produced by irrigation, but 70% of the irrigation water is groundwater. The standard number you see everywhere is 40%. But if you include the groundwater that’s flowing in the rivers nearly all the time, if you include that in the irrigation number, then it’s 70%. So groundwater, the 99% number, you almost never see that mentioned. The number for food is always underestimated. There’s just misunderstanding of the importance of groundwater.

There’s the concept of peak water, which isn’t given much attention, but then there’s the concept of peak groundwater and the depletion of aquifers around the world. So it’s the heart of the global water crisis and it’s becoming the heart of the food crisis from the water point of view.

Alpha: Can you give us some of the basics of groundwater? Like how much groundwater there is relative to freshwater? I don’t think people realize exactly how groundwater comes up and that streams are fed by groundwater. Can you give us some overview?

John: So when it rains in most areas, rainwater infiltrates through the soil and gets to the water table. The water table is the first free water. If you were to go out in your backyard and dig a hole, eventually you’d find free water in the hole—where the water level would come. If you take a post hole auger and make a hole, and if you’re in a part of the world where there’s enough rainfall, then not far down—five, ten feet or whatever—you’ll have free standing water. That free standing water level is the water table.

In the upland areas of the landscape, the water table has high energy water and that water flows toward the low-lying land in a flow system. Just like streams have a flowing regime, groundwater has a flowing regime. The water flows from higher elevation to lower elevation areas that are called discharge areas. Streams and rivers are almost all discharge areas. Wetlands are almost all discharge areas. By that term, we mean that there’s water seeping up and discharging into the surface water body.

What people don’t realize and what schools don’t teach is that groundwater is beneath us everywhere. It’s very unfortunate in the schools—there’s not a well outside the door. Students could have been measuring the water level at least at about any school in the world, seeing what’s happening to it over a long time. Sometimes when it rains, the rainfall gets down to the water table and recharges groundwater, but in many cases when it rains, water doesn’t get all the way to the water table and that water goes back into the atmosphere.

The most important—one of the most important concepts in the so-called water cycle—is the water table. If you look in the scientific literature, even generally in the literature, people in the news media and in the literature not written by groundwater experts refer to water levels. A water level is a meaningless term. It’s just the water level in a well someplace. That’s not usually the water table, and the water level in a well can reflect how water is being drawn out of the aquifer—it reflects many things. But it’s the water table that’s really the critical entity that relates to plants and forests and streamflow and all of that.

Alpha: So when rainfall infiltrates into the soil, some of that soil water is brought back up by the trees or used by the different plants, right? But then some of it, if it’s lower down, keeps seeping down into the aquifers.

John: Yeah, if it rains enough in many areas, then part of that rainfall makes it all the way through the soil. It makes it past the roots and gets to the water table. Generally, once it gets to the water table, it starts its subsurface journey. Now there are roots that go down to the water table, but most of the water that actually gets to the water table continues on, traveling in its flow system.

That travel—groundwater flows at rates of a few inches a day. A lot of groundwater is old. A lot of groundwater is decades or hundreds or thousands of years old. Unlike surface water, when you drill a well someplace, the water might be 10,000 years old or it might be a few months old. Much of the water used in the world is water that’s geologically old. That water is being mined. In the Middle East—Saudi Arabia and many countries in the Middle East and in Brazil—they’re pumping out water that’s tens of thousands of years old, water that went into the ground in the geological past.

But water that’s coming out of wells in North America and Europe is generally relatively young. It’s generally younger than 70 years. That’s in a way almost unfortunate, because almost all the water that’s younger than 70 years in the industrialized world has anthropogenic chemicals in it. It’s contaminated. I use the word contaminated not to mean that it’s going to kill you, but to mean that it contains chemicals of human origin.

 

Alpha: What is the extent of aquifers? Can you discuss a little bit about the world’s aquifers? What are some of the major aquifers?

John: There’s a map I show in my lectures of the world’s largest 68 aquifers, major aquifers. In the United States, there might be a dozen of them. There’s a major aquifer in Northern Africa. These 68 aquifers apparently supply 40% of the world’s drinking water, and at least a third of them are going dry. A third of them are apparently dewatered to the point where they can’t recover. Even if we stopped over-pumping them, they wouldn’t recover. They would take centuries to recover.

One of the big aquifers is the High Plains aquifer, also called the Ogallala aquifer in the United States. It runs from South Dakota to Texas. It’s so big and so highly used that its irrigation accounts for one-sixth of the world’s grain supplies. It’s being drained and in some places, it will be drained beyond use in another 20 or 30 years. That’s irreversible. In other words, the economics of agriculture in places like Nebraska is such that the farmers will drain it and then they’ll move on to something else.

That aquifer wasn’t really used before the 1950s. It began to get used in the 1950s because drilling machines developed after the Second World War and modern pumps allowed that aquifer to be used. Many parts of those states were almost semi-deserts before irrigation started. That story is worldwide. Pumps arrived, drill rigs arrived, and the dewatering of aquifers started in the ‘50s. In many cases, the pumps have to go deeper and the rate of pumping exceeds the rate of recharge. In other words, the amount of rainfall that makes its way to the water table is relatively small compared to the rate of pumping. We call that depletion. Many—a third of these 68 largest aquifers—are being depleted, which means the water is being mined.

People talk about climate change, but there’s two parts of climate change. There’s the natural climate change and then there’s the anthropogenic part of climate change. But in the past, there have been very long droughts. When long droughts come, the only water you have available is groundwater. If you’ve already pumped a lot of the water out of your aquifer, then you don’t have resilience.

A lot of these aquifers that needed to not be over-pumped are now lacking in resilience because when the long droughts come, they’ll be pumped because there’s no alternative. Now, how that’s going to play out in terms of world agriculture, I have no idea. But the Ogallala apparently supplies one-sixth of the world’s grain, and the Japanese and a variety of other countries are dependent on grain coming from that aquifer—grain from irrigation.

Alpha: Can you give us a sense of a little bit how the Ogallala aquifer works?

John: Well, when you’re pumping it heavily, most of the water that falls in that area that you’re pumping ends up in the wells. Before we started pumping, aquifers like that, the water might be decades or hundreds of years old. You have the natural flow system for groundwater where the groundwater is flowing along slowly. Then when you tap into it, you basically draw everything towards your wells. Of course, everything then changes.

In many areas, groundwater is increasingly contaminated because the water we’re pumping out is younger than 70 years. About 70 years ago was when all the use of industrial chemicals began. Now there’s the Green Revolution in agriculture, which is a total misnomer. In the late 1940s, the United Nations realized that famines could come back with a vengeance, and it was recognized that there needed to be preparations to prevent that.

The first part of the preparations to prevent famines was to develop better grains—better plants, better wheat, better rice and so forth. That was the first part of the Green Revolution. Then with that came fertilizers and pesticides. There was great fanfare to the Green Revolution in the 1960s and 1970s because the amount of food on the world market was almost an oversupply at times. The fear of famine basically disappeared and the credit was given to, shall we say, modern agriculture—given to fertilizers and pesticides.

Whereas in fact, a major part of the increased food supply that went along with the Green Revolution was pumping groundwater. It was basically the invention of good drill rigs and modern pumps. You almost never read that. Now the Green Revolution, the increase in agriculture production per acre, leveled off in 1980. The world has been able to produce more and more food apparently not by increased productivity on the soil, but by basically cutting down forests and developing more land.

But the Green Revolution, that type of chemical agriculture, depletes the carbon in the soil. One of the results of the Green Revolution has been to have less productive soil. Now that’s separate from the irrigation issues. You’ve got soil becoming less productive and you’ve got many aquifers becoming less productive. But many aquifers are going to become very much less productive apparently in another decade or two, contributing to what people are saying is going to be a globalized food crisis.

Now in Canada, it used to be that we were relatively self-sufficient in food. Then the Green Revolution came along, and now we get much of our food from California and Mexico. When we go into a grocery store here and we look at where our fruit comes from, where our raspberries come from and all of that stuff, much of it’s coming from California and from Mexico, and much of that food is unsustainable food. That’s got to do with the global food supply chain and basically the idea of virtual water.

Whenever we look at what we’re eating, we should realize that it’s got water in it and the water is referred to as virtual water. The British professor who developed that term got the Stockholm Water Prize about 20 years ago. Water is being shipped around the world in food, and much of this water in food is unsustainable water. It’s unsustainable because it’s from aquifers that are being depleted.

Now Saudi Arabia began to pump water at a crazy rate a few decades ago as their population increased. They’re beyond peak groundwater, far beyond their peak groundwater. Now they basically sustain themselves with oil money that allows them to buy food, which has all this water.

Alpha: So the whole Green Revolution—we give credit to all the synthetic fertilizers, but the credit isn’t really warranted because it actually messed up the soil. But actually, you’re saying that groundwater was also a big part of that, because we figured out how to irrigate a lot more. Now we’re realizing we shouldn’t be slowly destroying the soil with these chemicals because then you can’t produce food in the long run. But also, the other thing is that we’ve depleted the groundwater to make that revolution. We’re facing this double whammy kind of crisis.

John: We’re facing a double whammy—depleted soil and depleted aquifers. As I mentioned, many of the aquifers are so depleted that even if we stop pumping now, it would be decades or centuries before the water level gets back up. When we deplete an aquifer, the pressure in the aquifer goes down. That means your pumps have to go deeper, but also the water table goes down. You’re basically drying out the land.

In many parts of the world, early on there were flowing wells—flowing wells all over the place in Europe and North America. You hardly see a flowing well now. And there were springs. What we’ve done over the last 70 years is we’re drying out the continents. We don’t see springs and we don’t see flowing wells.

Henry Darcy, who developed Darcy’s equation, which is the basis for groundwater science, did that because there were so many flowing wells in France and so many flowing fountains in Paris that he was curious about it. Now you don’t see any of that.

Alpha: You also brought up the whole idea of virtual water, right? I was wondering if you could explain a little, because that whole idea of virtual water is important. Now that we’ve depleted the groundwater in certain places, we’re depleting virtual water.

John: The term virtual water was developed by Tony Allen, a geography professor in London. He realized that when we look at food, all food has water to produce it. Then he looked at the world—he traveled a lot—and he realized that water was being shipped around the world in food.

He recognized that places like Saudi Arabia could continue to exist with a large population if they could import food, and that food comes with water. There’s a research group in the Netherlands that took over that idea and quantified it. They did a lot of quantifying and they’re still at it. They draw maps and diagrams with arrows indicating how much virtual water goes from the US to Japan, how much virtual water goes from Peru up to Canada, et cetera.

When I buy my blueberries, which I like very much, I always look to see where they come from. Many of the blueberries we buy in Canada come from Peru. When I started looking into that a few years ago, there’s actually a peer-reviewed paper published on that pointing out that much of the agriculture product from Peru that’s entered the global food marketplace is produced by dewatering their aquifers.

The countries where you have money can buy their food and can have blueberries at any time of the year because they’re shipped in. Much of that is virtual water that’s unsustainable. The key is unsustainable virtual water.

Alpha: The virtual water depends partly on the groundwater; it’s now networking the world’s access to groundwater in a way that when you collapse, usually it’s just a local effect, but now it’s actually going to have repercussions, right? If Saudi Arabia is using Arizona water and buying all the land, and that collapses, that affects Saudi Arabia and multiple other places.

John: Economists of course really like the idea of globalization. Decades ago, it was thought that the globalized movement of food around the world—provides more security, food security, because then you’re getting your food from a variety of places. But the end result is in fact increasing food insecurity because of the virtual water part of it.

Alpha: Can you say a little bit more—we talked about Ogallala in the US—can you talk about some of the other continents and the state of the aquifers there?

John: Yeah, the other place in the US where there’s a lot of over-pumping is California. As you well know, when a drought comes to California, there’s a huge crisis and drill rigs come from all over and they pump more and more and there’s more land subsidence, et cetera. The Central Valley of California and other parts of California are thriving in many cases on unsustainable water.

In other parts of the world—in North Africa, in Morocco, in Algeria, Saudi Arabia, Egypt—in general, where people are pumping groundwater, it’s unsustainable groundwater. But I might mention the whole issue of drought. California thinks they’re having a drought when they don’t have lots of rain for two or three years. By the third or fourth year in California, it’s a crisis and it’s referred to as a drought. Well, that’s barely a drought. In paleohydrology, a real drought is ten or fifteen years.

We humans have gotten so off track in not realizing the dependency we have on water that we’re not realizing that with or without any carbon dioxide-induced climate change, big droughts should be expected to come. Spain has had a long drought—I guess it just broke recently. Spain had a four-year drought that was really affecting their agriculture and their exports.

South Africa—when the media wants to talk about drought, they talk about South Africa. In 2016 to 2017, they had a two-year drought. I actually happened to be there at a conference in 2017 and they were right in the midst of the drought. They were talking about turning the taps off and all of that stuff. But that wasn’t a drought at all. It was two years without rain and their reservoir went dry. They hadn’t backed it up with wells or anything. There was a big crisis to bring in drill rigs, but that was all too late.

São Paulo in Brazil had a four-year drought and that was a total calamity down there. That’s only four years. In general, when it comes to drought, our security is gone in many cases because we’ve drained our aquifers. The purpose of not draining an aquifer is to save that water so that when you have a drought, it’s there as a reservoir. Pretty well all the major aquifers in a dry climate area are drained to the point where resilience is lost.

You never hear mentioned in these cases that these are short periods without rainfall. And you never hear mentioned in general how the aquifers that are supposed to provide the resilience are providing it. In some cases, they’re not providing it because the wells aren’t located in the right places at the right depth.

Now, India—India is a total crisis in the making. India pumps like 90% of the world’s groundwater. They’ve got 1.4 billion people. India’s going to add 300 million people before they peak. They have 600 million people dependent on agriculture. When drilling wells became common in India, which was in the ‘70s and ‘80s, all the farmers switched to what they call tube wells.

Before that, they had dug wells. We switched from dug wells to tube wells and that changes everything. Then the government subsidizes electricity. India has a groundwater crisis in many areas because with subsidized electricity, the farmers have pumped too much water and in some cases the water is arsenic, et cetera.

Iran is now into five or six years of drought and has the most severe water crisis in the world. People who look at Iran say there’s going to have to be major human migrations. They mismanaged their water. Apparently they built dams and done all a bunch of things. But one of the things that we’ve done in human societies is engineers like to build dams. The world has tens of thousands of dams. Huge numbers of dams have been built. When drought comes, the dams go dry. That’s what’s happened in Iran and other places.

If the only water that humans have, other than melting glaciers, that is there when you have a drought is groundwater, and it needs to be viewed as being a very precious resource because it’s the water of last resort.