There has been a lot of talk this summer about a so-called “Day Zero” in Mexico City, when the city would run out of water. Much of that conversation has also included warnings about which other cities could face a similar predicament. Day Zero has not happened there, but that doesn’t mean the region isn’t facing serious water problems.
Caroline Tracey, a geographer and writer, joined The Show from Mexico City to discuss what the water situation has been like for her recently. Tracey said here have been cutbacks in the water supplies in certain parts of Mexico City.
Dean Chahim, a professor of Environmental Studies at New York University where he studies the water crisis in Mexico City, joined The Show to discuss if Day Zero was a legitimate possibility.
Full conversation
CAROLINE TRACEY: Well, there was a lot of talk at the beginning of this summer, about a possible day zero. So, a day in which one of the city's water systems would cease to provide water at least for this season and for the foreseeable future, the rains have been pretty good this summer. So it seems like the day zero possibility has been pushed back. But that doesn't mean that there hasn't been pretty strict water rationing in Mexico City. It varies by neighborhood.
So there is definitely a justice component where you know, more well-to-do neighborhoods will have less water rationing, and neighborhoods that are more peripheral will sometimes just lose service altogether where I live, which is my partner who is from here, his apartment is kind of a central but working class neighborhood.
And so the type of rationing that we've seen has been that there will be periods of weeks where there is water service for part of the day, one day and then no water service for a day or two and then partial water service for another day kind of on a rotation like that, that I would say the month of July was sort of the most the most extreme rationing. And the other kind of phenomenon that has been very noticeable is that there's a lot more water trucking going on.
MARK BRODIE: So what has that rationing meant for you and your neighbors? Like how have you had to change the way you go about your, your days and go about your lives?
TRACEY: There's an interesting set of routines that you develop. I think, you know, there's sort of a sound that you hear when the water pump in your building starts to bring water up to the tanks that are on the top of the building. So you'll sometimes just hear this buzz start and it sort of launches you into, you know, the routine which involves filling buckets so that you have water that you can use to wash the dishes or flush the toilet, that kind of thing. I think probably many people around the city have these buckets in their shower that are kind of the reserve buckets for when the water goes out.
BRODIE: So, do you get the sense that people are using less water now with this rationing or they may be just using the same amount of water over more time?
TRACEY: It's a good question. I think that probably, you know, each household in each family adjusts in a slightly different way. And I think it's also important to point out that there are areas of Mexico City that really have consistent water shortages.
BRODIE: So what lessons do you think those of us in the American Southwest might be able to learn from the experience of, of Mexico City and you know, the water shortages there and how that's affected people.
TRACEY: Well, I think there are some really interesting connections in terms of the geology and hydrology of Mexico and the Mexico basin and the southwest and the way that we get water in the southwest. One of the sort of most fundamental is just the type of basin that Mexico City is in. It's a closed basin. So instead of a valley, it's like, it's like more like a bowl. Everyone calls it the valley of Mexico, but it's a misnomer.
So when you see the official documents from the city, from the irrigation Commission or the Hydrology Commission, they say the basin of the Valley of Mexico, which is sort of redundant. But that geologic formation is very similar to, for instance, Salt Lake City. So you have this very clear parallel between the sort of dried up lake at the base of the Mexico Basin and the Great Salt Lake in Salt Lake City.
BRODIE: What might all this mean for a place like Arizona which you know, like parts of Mexico rely on in some places, groundwater, some places surface water. There's obviously Colorado River water at play here. What kind of parallels might you be looking at between a place like Arizona and what's currently happening in Mexico City?
TRACEY: I think there's an important parallel in terms of where we in the southwest in Arizona get our water and what's going on in Mexico City, which is that in Tucson, for instance, it's a mix of groundwater and Colorado River water. So essentially Arizona Project water and, and Mexico City has a similar mix. So it's about 60% groundwater and then about 20% from a system they call Cutzamala, which is coming water that comes from a different basin.
And so that's essentially the same concept as the Central Arizona Project where water does flow uphill, right? There's this very energy intensive system of aqueducts and pumps that brings water from Lake Havasu to Tucson or to Phoenix also. And there are these sort of inter basin systems around the Southwest and there are more on the table.
So I think both thinking critically about groundwater and the rapidity with which we are using up a resource without sufficiently recharging it. And also the intense engineering required to do these inter basin transfers and bring water from a far away basin to another basin are similar similarities between Mexico City and the American Southwest.
BRODIE: Yeah. What have the conversations been like in, in and around Mexico City in terms of trying to figure out a solution to this? Because I would imagine that, you know, you, you and your neighbors would not be thrilled for, you know, into the foreseeable future to only have water certain days a week.
TRACEY: I think that it's definitely a topic of conversation. It did come up in the presidential debate. But it's one that still continues to be without a clear resolution. One problem that Mexico City has that I think is not out of the question for the American Southwest is that the water that falls on the basin, all sort of drains to the lowest point.
So if you can picture the Great Salt Lake, it's essentially the same concept. There was a lake that was drained to build the city. And so in the same way that the water in Utah drains to the Great Salt Lake,, the water drains around Mexico City, but to avoid flooding, they built a drain, they built a tunnel out of the valley. And the problem with that is that it means that the groundwater does not get recharged.
So when you have a place where it rains or snows significantly, and in Mexico City, it does rain significantly. It rains like 100 and 50% more than it rains in London, you want to recharge the groundwater so you can continue using it and, and that is something that does not happen here because the water gets drained out through this tunnel.
And so I think one thing that we need to be thinking about both in the southwest and in Mexico City is how do we recharge groundwater? And I think that's a very kind of active field for people that want to go into hydrology and water management is thinking about how best to do this.
BRODIE: All right, that is writer Caroline Tracey speaking from Mexico City, Caroline, nice to talk to you. Thank you.
TRACEY: Likewise. Thank you.
BRODIE: As Caroline referenced, there have been cutbacks in the water supplies in certain parts of Mexico City. And as my next guest explains that not, that's not necessarily a surprise. Dean Chahim is a professor of environmental studies at New York University where he studies the water crisis in Mexico City. When I caught up with him recently, I asked if Day Zero was a legitimate possibility.
DEAN CHAHIM: No, that's kind of, unfortunately, it's sort of, it's a good, it makes a good headline, but it's not really the story. What's going on is that Mexico City, the sort of metropolitan region I'm going to really talk about the whole metro region of 22 million people. They depend on basically two main sources of water.
One is imported water and one is local water from the ground groundwater aquifer and of that imported water. The majority of it comes from this Cutzamala system, which is an aqueduct that connects the city to a series of dams, reservoirs which are quite far away from the city and the water is pumped up nearly half a.
And that, that system of reservoirs is what's really under in crisis right now because of climate change, as we know, you know, rains have become quite uneven and this year has been a particularly bad year in terms of filling the reservoirs.
And so they were the engineers who managed that system in the Federal Water Ministry started to really throttle down the amount of water and warn the population that they were going to have to be serious cutbacks in the amount of water that they, that they bring to the city from those reservoirs because they don't want them to go to zero.
And so the Day Zero was basically a projection of when they would have to almost cut off the supply to the city, which would be a real problem. Because it is about 30% of the supply of water to the entire metropolitan regions. But again, it's 30% it's not the entire water source.
It's not like nobody would have water. It would just be certain areas of the city that are more dependent on that system based on the way the pipes work would be in particular crisis. But other parts might feel like there was almost nothing happening. So it's kind of very uneven problem.
But the reason why this became such a media story, really, I think is that suddenly the areas where most people with money and also some foreign journalists live were the ones that were suddenly facing much more of the water cutbacks than they're used to.
BRODIE: How severe could the cutbacks within that 30% of the supply be like, could they be shut off altogether or are we just looking at less than, than what folks are used to?
CHAHIM: I think I'm not sure if it would be cut off completely. I don't think so. I think they would basically bring it down. I mean, it depends basically on whether or not it continued to rain or didn't rain at all. I think they would kind of have to make those decisions as you know, they'd make it on a day to day basis.
BRODIE: So for the other 70% you kind of alluded to the fact that, you know, folks who get their water from that supply might not notice there's much going on. Like, are there any cutbacks in that supply or is that pretty much as is?
CHAHIM: No, there, there, there have been cutbacks all over. And the reason why is because Mexico City has a very well developed, unfortunately system of water tanker trucks. And so they have these water tanker trucks fill up at wells, usually around the city and then they redistribute that water to other, they can kind of go to businesses, they go to neighborhoods, they go to to people's houses directly and they will refill people's water cisterns, which is because of the regular water supply is something that people are quite used to many buildings have.
And so these are underground storage tanks for water. And so they'll refill these underground storage tanks or if people don't have them, they are water barrels or whatever they have to store water in. And so that is a kind of above the ground redistribution that happens. And that means that also engineers who are managing and, and, and throttling the supply with their valves all through the system.
You know, they might give more priority to filling those water tanker trucks such that they can spread out the water more evenly. They also might give priority based on politics too. I mean, which areas many, you know, you might have a rich neighborhood next to a poor neighborhood and they depend on the same wells. And so if that rich neighborhood also, overall, that area is getting maybe say a part of its water usually comes from this Cutzamala Aqueduct if they're facing a cutback overall, you know, they don't have to cut back Both neighborhoods equally.
You know, there's a way in which depending on the geography of where the valves are, etcetera, they can kind of give certain neighborhoods priority over others. And so people are definitely feeling the cutbacks all over, but there are places in which people haven't felt it at all.
BRODIE: What does the water usage over time look like? I mean, are people using the same amount of water they've used in years and decades past, has it gone down, up?
CHAHIM: I think it's been quite steady. I think that the, so that's not, we're not thinking, in fact, if anything, I imagine it's gone down, I think just out of necessity because people don't have as much water. And so there, there are probably, there are certain areas in which people are using, you know, the wealthy areas use a lot of water.
I mean, the per capita use of water is radically different in the western part of the city that's wealthier versus the eastern part which is poor. And people in the eastern part of the city are very well versed in recycling every last drop of water. Whereas in the western part of the city where most tourists would go to, you know, they have swimming pools, people don't even notice it. It seems, everything seems fine. So there's a lot more profligate use of water in those areas.
So by necessity, people have had to use less. I mean, if you just think about the fact that the population has grown by this amount, by millions of people again,, and the water supply has been the same there, you know, by definition, there has to have been actually a decline in per capita water usage, but again, it's very uneven. And so the poor, generally speaking are the ones who are suffering the most here.
BRODIE: All of that makes it kind of hard to see what the solution is here or if there is a solution here, I mean, are there ways for Mexico City to either conserve enough water or to get water from other sources to try to solve this problem?
CHAHIM: You know, I think the solutions people have been proposing really for more than, you know, I I definitely not the first person to suggest anything here. So the solutions have been well known for a long time. I mean, things like rainwater catchment that actually there's been a lot of progress on that. I want to say that's one bright spot. People doing rain because you get something that's different for reps, for your listeners, you know, unlike Phoenix or the Southwest Mexico City is not an arid place at all actually.
You know, and so it's quite even more ironic, it's a place that floods constantly because it has so much rain. And so there is a real possibility for catching, you know, doing rainwater catchment off people's roofs of the buildings and filling those cisterns with, with that treated rainwater. And so that's something that the government has been pushing and I think could be expanded.
There's also been attempts and lots of pilot projects that things like groundwater injection, that means getting water treating it and then pumping it into the aquifer rather than just pulling it out. And that could kind of be a storage, a way to store water in between rains and actually then use it, pump it back out for, for drinking. There's also been attempts to restore rivers and lakes. I mean, there have been small attempts. It's just, it's a matter of actually giving the kind of really capital that you that's required to make these into much bigger programs.
And so I think that I'm a little bit optimistic, the current, the new mayor who's just been elected, she is saying good things whether or not actually she is able to do them. And she's mentioned some of the things I just said, you know, that remains to be seen.
BRODIE: All right, that is Dean Chahim, a professor of Environmental studies at New York University. Dean, thanks so much for your time. I appreciate it.
CHAHIM: Thank you so much. Appreciate it. Bye bye.
