A Squishy Border Dispute, Deep Below Texas And Mexico

17:28 minutes

The Rio Grande riverbed in Big Bend National Park. But disputes over water on the Mexico-Texas border go far deeper than the river. Credit: SCEhardt via Wikipedia

In the Southwest, water is at a premium, with every drop in demand from agriculture, industry, and growing populations. The Mexico-Texas border is no exception. Strict rules govern who can take water from the Rio Grande, with each country owing a certain amount of water to the other as the river winds back and forth.  

But the surface water isn’t the only liquid in play. Far below the surface, hidden aquifers straddle the border—and the water within them is largely unregulated. Rosario Sanchez of the Texas Water Resources Institute has identified a number of aquifers that aren’t recognized in the international compacts governing the water trade along the border.  She joins Ira to discuss her research, along with Zoe Schlanger, environment reporter for Quartz, who has written about the trans-border aquifer problem as part of a collaboration between Quartz and the Texas Observer for a series called Shallow Waters.

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Segment Guests

Zoë Schlanger

Zoë Schlanger is author of The Light Eaters and a climate change reporter at The Atlantic. She’s based in Brooklyn, New York.

Rosario Sanchez

Rosario Sanchez is Senior Research Scientist and Associate Graduate Faculty at the Texas Water Resources Institute of Texas A&M University in College Station, Texas.

Segment Transcript

IRA FLATOW: This is Science Friday. I’m Ira Flatow. In the Southwest, as you know, water is at a premium, with every drive in demand from agriculture industry, growing populations– and the Mexico-Texas border is no exception. Strict rules govern who can take water from the Rio Grande, with each country owing a certain amount of water to the other as the river winds back and forth. But the surface water is not the only liquid in play. Far below the surface, hidden aquifers straddle the border, and the water within is largely unregulated.

So what does that mean? Who owns the rights to that water? Joining me now to talk about it is Zoe Schlanger. She’s an environment reporter with Quartz and author of Shallow Waters, a multi-part collaboration with the Texas Observer. Welcome back.

ZOE SCHLANGER: Thanks, Ira. Great to be here.

IRA FLATOW: Thank you. Rosario Sanchez, she’s a senior research scientist and associate graduate faculty with the Texas Water Resources Institute. That’s at Texas A&M in College Station, Texas, and her work is the subject of one of Zoe’s articles. Welcome to Science Friday.

ROSARIO SANCHEZ: Good afternoon. Thank you for having me.

IRA FLATOW: You’re welcome. So, OK, set the stage, set the scene for us. How big a deal are the water rights in the region? They must be huge, right?

ZOE SCHLANGER: Sure, yeah. I think what’s really important for people to understand is that the entire Texas-Mexico border is the river. And the Rio Grande is running out. The federal government acknowledges that, by 2016, there won’t be enough water there to sustain the growing populations in the region. And a lot of that’s due to climate change– more droughts, also booming populations that will double in the next few decades.

But when we’re thinking about surface water, that running out means everyone will probably be turning to groundwater. That will be the only other water in the region that’s accessible to people. And we don’t have a treaty for that. Right now, there’s no international treaty between the US and Mexico governing groundwater. And it’s a free-for-all, more or less.

On the Texas side, it’s all about property rights. If you own some land, the water underneath it, that’s yours. And on the Mexican side, it’s all done by permits from the federal government. But neither side really acknowledges that those aquifers are the same on each side. It’s the same source of water for US and Mexico.

IRA FLATOW: So that’s something no one’s really talking about, right? You don’t hear a lot of discussion about the water and the aquifers.

ZOE SCHLANGER: You really don’t. It’s really hard to talk about water you can’t see. It is– people say it’s the least sexy water topic out there. But we don’t want to wait too long. Once that river runs out, you’re going to have a real run on groundwater. And you don’t want to be negotiating these things in a moment of an emergency. That’s not a great way to do politics.

IRA FLATOW: And Rosario Sanchez, that’s where you come in. Your work involves mapping these underground aquifers. How many of them are there? How much water are we talking about?

ROSARIO SANCHEZ: We don’t know how much what we’re talking about. We know there’s water, and we know the water is being used already. We have been able to identify between Texas and Mexico only around 15 formations, hydrological units, because we haven’t got all the data to confirm that they are actually aquifers. But we know that there is a good to moderate water quality in those regions, and it’s being used.

So people are already using that water. The problem, as Zoe mentioned, is the regulation of that water used in the region. So from those 15 formations, you can see that we have only been able to recognize as transboundary only four of them.

IRA FLATOW: Why is it so hard to recognize the boundaries and where they are? I know the oil well drilling’s been going on there for a century, right?


IRA FLATOW: So are their maps from oil drillers that might say, hey, here’s an aquifer?

ROSARIO SANCHEZ: Well, the problem is the data. And there actually– there’s no requirement, international requirement, or binational requirement to actually collect that kind of data. So the private companies, they do it. They do it because they are required to do it by their own standards of their companies and because of their own sustainability of their economic growth. But it has nothing to do with the condition of the aquifer, water quality, uses, et cetera.

So it’s kind of complicated. Why is nobody taking attention? Because I don’t think– I mean, it helps the political authorities at this point to acknowledge that there’s something going on there. The interest is growing; however, it is not enough. Because the only way to recognize an aquifer as transboundary, they have to prove that it’s actually transboundary according to international standards, which are the UN’s standards.

So who’s going to do that? Mexico or the US? Who’s willing to take the first step? Who’s going invest in that? There’s not a lot of money invested on these things so far. And the only institute that takes care of water, transboundary waters, so far, is the IBWC– International Boundary Water Commission. And they are not authorized by the treaty to regulate ground water. So it’s like a very gray, super gray, area that nobody wants to touch.

IRA FLATOW: Zoe, you’re nodding your head.

ZOE SCHLANGER: I am, yeah. I mean, it’s complicated for all of those reasons that Dr. Sanchez just mentioned, but also because, can you imagine if ground water is thought of as a property right in Texas, what’s going to happen when you tell people in Texas that the water they’re taking from their well is also reducing the water from a Mexican farmer across the border and that they need to abide by international laws? As Gabriel Eckstine, also at the same institute as Dr. Sanchez, told me, it’ll be litigated like heck.

IRA FLATOW: But we already have precedent, I mean, with the river water, don’t we? You can’t pump out all the water. You have to leave some of it for someone else, right?


IRA FLATOW: Can we make a similar regulation or some similar cooperation between the countries?

ZOE SCHLANGER: Well, you can’t do much of that if you don’t have the basic science. Right now, we really just don’t know, as Dr. Sanchez said, what is there. And her work is quite remarkable because the US and Mexico only acknowledge four aquifers as actually crossing the border. She’s found in total along the whole border 36, and 15 are in Texas.

IRA FLATOW: Wow, so just agreeing on what the facts, are Dr. Sanchez, is difficult because we don’t have enough information?

ROSARIO SANCHEZ: Exactly. It’s easy to regulate surface water. You can actually see surface water. You can actually measure, easily, very easily, surface water, but it’s not the same story for ground water.

IRA FLATOW: Yeah, because you can definitely say, on the surface, your water is X; your water is Y. But I imagine the layers underground, their formations, they’re just not as easy to look at.





IRA FLATOW: Go ahead. I’m sorry, Dr. Sanchez.

ROSARIO SANCHEZ: No, I was only going to mention that if you don’t know what’s going on underneath, how can you regulate something that you actually haven’t invested in? Nobody thinks about that. And this is not just an international bi-national issue. I mean, within Texas, ground water conservation districts, for example– I mean, they regulate groundwater according to their own administrative boundaries, not hydrological boundaries.

So they have the same issues within the state. Because ground water conservation districts don’t talk to the other ground water conservation districts about ground water extractions that might be extracting from the same aquifer than its neighbor. So it’s a problem, not just internationally talking, but within domestically it’s also a challenge.

ZOE SCHLANGER: I’d also just like to put it in the context globally. This is a border issue everywhere. There’s more than 300 aquifers that cross international borders all over the world, and there’s only, officially now I believe, four treaties of any kind governing that. So as the world is warming and water scarcity is becoming more of an issue everywhere, we’re going to see this as a huge geopolitical issue. That’s just simply not talked about right now.

IRA FLATOW: 844-724-8255 is our number. You can also tweet us at @scifri. I mean, I hate to make a pun out of it, but this really has flown under the radar– really way under the radar–


IRA FLATOW: –in issues. But people on the ground, people who live there and the people who were neighbors– Mexico-US borders, they must understand this as a problem.

ZOE SCHLANGER: Well, interestingly actually, if you look at– Yale did a great study of climate perceptions on a county level in 2016. And if you look at the state of Texas, most of the state doesn’t have a favorable view of climate scientists– doesn’t quite think climate science is credible. But if you look at the border counties, the ones right along the Rio Grande on the border, where the temperature is heating up very fast and water scarcity is part of their life, they have a much clearer view that climate change is happening and that some of the highest percentage of populations that believe climate change is directly harming them now.

IRA FLATOW: And some of the cities realize they have a water shortage, and they’re doing– you know, I was reading research from your own website about El Paso.

ZOE SCHLANGER: Yeah. Yeah. Yeah, me and my colleague, Naveena Sadasivam, at the Texas observer, we wrote these pieces together. And she went and talked to farmers in the region and cities in the region that are buying water ranches, for example, to keep sustaining them in future. El Paso is a fascinating case. They are on the absolute cutting edge of water technology, partially because they have to be. They are extremely dry– nine inches of rain a year. That’s drier than Namibia, which is the driest country in sub-Saharan Africa.

And El Paso is getting way into the desalination game. They are desalinating brackish groundwater. They are reusing waste. They’re planning in the next 10 years to open the largest plant in the US that will take human waste water and treat it to drinking water standards and pipe it directly back into the water system– a closed loop system.

IRA FLATOW: I was at the American Water Works association meeting, and I met somebody involved in that process.

ZOE SCHLANGER: Oh, really?

IRA FLATOW: Yeah. And he’s pitching this story. I mean, I thought was a great story. And I said to him, how do you know– is there a difference between the taste of the water that they’re going to be drinking? He says, yes, there’s a big difference. I said, oh, what’s that? He said, the processed water tastes much better.

ZOE SCHLANGER: I mean, the regulations they have to adhere to make sewage water into drinking water– they’re very tight regulations. It’s a highly technological process. So I have not tasted it myself, but I believe that.

IRA FLATOW: And Dr. Sanchez, if people have a well in their backyard, did they actually think about where the water is coming from at any point?

ROSARIO SANCHEZ: It depends on who you talk to. If you’re talking about the farmers in the valley, for example, they might because they rely on that water for their business. If you think about people in San Antonio, for example, they do think about that because they have a history of the Edwards Aquifer, which is the only regulated aquifer in Texas, because of the species that was in danger. But if you talk about, for example, people here in College Station, I mean, they barely think about that.

And they depend 100% on groundwater. So it depends on your case. It’s very localized. The way ground water works for– and the perceptions in ground water are very different from surface water. It’s very localized. It’s very attached to private property.

And people have said that to me personally. Like, why do I have to care about my neighbor? I have my water here. It’s mine. It’s below my property. Why would I think about the other side? And very few of them, except if you’re an academic or an expert, that you would know which aquifer you’re actually extracting from.

But a regular person don’t think about that– not even the quality of the what they are extracting. They trust EPA standards in all of that, but they don’t think about future consequences because you can’t see them. You can’t see the water moving. You can’t see where it’s coming from.

So it’s a rather interesting psychological issue, actually. Because it is not just only between Mexico and the US or Texas and Mexico. It’s all over the world. I mean, there’s a reason why there is non– there’s no one agreement or treaty that regulates or sets the standards of groundwater, transboundary groundwater used along the world. It’s changing slowly.


ROSARIO SANCHEZ: I mean, the interest is growing. Yes, the interest is growing. IBWC has put a lot of effort in getting this. Even though they don’t have, legally, the authority to regulate groundwater, if somebody’s going to regulate, it will be them because that’s the only institution we have bi-nationally.


IRA FLATOW: I’m sorry, didn’t mean to interrupt, but I have to tell our listeners, I’m Ira Flatow. This is Science Friday from WNYC Studios. One last issue– you can’t talk about the border between Mexico and the US without talking about President Trump’s wall idea. How does that play into the water discussion, Zoe, in the area here?

ZOE SCHLANGER: Well, one thing to visualize, again– that the Rio Grande is the border between Texas and Mexico. So when you talk about putting up a wall, you’re talking about putting a wall on the US side on the banks or near the banks of that river. And that river floods regularly like most river systems.

There’s been a lot of back and forth about where that wall would go. Most of it would have to be put in or near a flood plain. We’ve already seen in parts of the wall that have gone up in Arizona, specifically in Nogales, Arizona– right across the border from Nogales, Sonora, that when there’s heavy rains and flooding, the wall had acted like a dam. The debris builds up on one side, and that floodwater can’t escape. And we saw it in 2008. It caused $8 million worth of damage.

And actually, two people drowned on the Mexican side due to that wall acting as a dam. So it’s a very touchy issue from a water engineering, civil engineering perspective even. And trying to negotiate between the forces that want that wall in place and the people on the ground who understand what would happen in that ecosystem is very tenuous.

IRA FLATOW: Dr. Sanchez, any comment?

ROSARIO SANCHEZ: I’ll let Zoe respond to that question.


IRA FLATOW: Well, let me ask you the other political question. Are we just in a deadlock over discussions about the aquifers? I mean, it seems like it’s such a hot potato. It’s better left untouched, right?

ROSARIO SANCHEZ: Yes, you have described it the perfect way, but I think that’s changing, because there’s a lot of interest, growing interest. Because, and we have discussed this already, we’re running out of surface water.

IRA FLATOW: Well, are we going to get one international treaty that everybody signed, or do you look for treaties for every different border for different countries?

ROSARIO SANCHEZ: I think they will have to be different. I think there will have to be regional, local agreements first before even thinking about a binational agreement on ground water because it’s so complex. And the histories among neighbors are different. I mean, the history between Mexico and Texas is completely different compared to Mexico in Arizona, for example, or even California.


ZOE SCHLANGER: But just to put this into some context, the IBWC, which is on the US side, it’s run by the State Department on the Mexican side, it’s a federal negotiating body– it takes them years to come up with a single amendment to the main treaty that governs this water. And we really don’t have several decades to wait to do this, because we’re looking at 2060 as an early deadline of that river not being able to support the populations.

IRA FLATOW: Dried up.


IRA FLATOW: Dried up.


IRA FLATOW: And our time has dried up. I want to thank Zoe Schlanger. She’s an environment reporter with Quartz and one author of Shallow Waters. This is a terrific multi-part collaboration with the Texas Observer. Thank you. Congratulations on that. And Rosario Sanchez, she’s a senior research scientist and associate graduate faculty with the Texas Water Research Institute. That’s at Texas A&M University in College Station. Thank you, too, Dr. Sanchez, for joining us.

ROSARIO SANCHEZ: Thank you. Thank you, and–

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