Hmm.

I think that a major problem here is that the water that they’re getting isn’t “free” in terms of Mexico City’s overall water problem. Like, if they capture water, there’s probably two things that don’t happen that would have happened:

• It would have gone into a river or other body of water.

• It would have drained into the ground, headed down to the eater table.

The problem is that those other two things are…actually depleted sources of water for Mexico City. Like, they’re running low on surface water as well as seeing ground subsidence because groundwater is being overdrawn.

https://eos.org/articles/groundwater-pumping-is-causing-mexico-city-to-sink

Groundwater Pumping Is Causing Mexico City to Sink

Authors of a new study published in Geophysical Research Letters used satellite data to narrow these estimates. They found that between 1 and 13 cubic kilometers (0.2 and 3 cubic mile) of groundwater have been pumped each year since 2014 to serve the 22 million residents of the Mexico City Basin. (For reference, that’s enough water to fill up to 5 million Olympic-sized swimming pools.)

Maybe putting water into tanks immediately might save a bit due to limiting evaporation. But I think that most of what’s happening here are just residents of Mexico City fighting other residents for a larger share of what water is available.

I wonder if it’s possible to bring in water elsewhere from in Mexico. In California, we have a large water project that pumps water over mountains from the temperate rainforest part of the Pacific Northwest to the arid south, recovers part of the energy expended as the water descends.

Or if Mexico City could just desalinate water, which we also do. Whole ocean out there.

You’d want somewhere to be relatively low-elevation for that.

kagis

Ouch.

https://en.wikipedia.org/wiki/Mexico_City

Mexico City (Spanish: Ciudad de México,[b][11] locally [sjuˈða(ð) ðe ˈmexiko] ⓘ; abbr.: CDMX; Central Nahuatl: Mexihco Hueyaltepetl,[12] Nahuatl pronunciation: [meːˈʃiʔko wejaːlˈtepeːt͡ɬ]; [13] Otomi: 'Monda) is the capital and largest city of Mexico, and the most populous city in North America.[14][15] Mexico City is one of the most important cultural and financial centers in the world.[16] It is located in the Valley of Mexico within the high Mexican central plateau, at an altitude of 2,240 meters (7,350 ft).

Yeah…That’s not great.

Maybe just going to have to shift population to a different city in Mexico.

https://en.wikipedia.org/wiki/List_of_cities_in_Mexico

The second-largest city is Tijuana, which is right on the Pacific – so unlimited water, as long as you have the energy – and just above sea level.

The third-largest city is Ecatepec, at the same altitude as Mexico City. I wonder if it has water problems.

checks

Apparently it adjoins Mexico City.

https://www.courthousenews.com/illicit-water-trade-worsening-hydraulic-crisis-in-state-of-mexico/

Illicit trade worsening water crisis in state of Mexico

Residents of Ecatepec, north of Mexico City, say they have gone months without running water and are forced to buy it from what they described as a “mafia.”

Looks like the next largest city is León, Guanajuato.

It’s also pretty high-altitude, on the same plain as Mexico City. 1,815 m (5,955 ft). Does it have lots of water?

kagis

Sounds like no.

https://www.scielo.org.mx/scielo.php?pid=S2007-09342022000300527&script=sci_arttext&tlng=en

Water is a natural resource on which there is great pressure and problems in the world and in Mexico. In the aquifer of Valle de León, Guanajuato, there is scarcity, pollution and overdemand by the population of the metropolitan area of the City of León, one of the most populated in the country.

Well, maybe the answer is just gonna have to be shifting population to Tijuana and doing desalination there. We have a large desalination plant in San Diego in California, just to the north of Tijuana, so I’m sure that it’s technically doable.

https://en.wikipedia.org/wiki/Claude_"Bud"_Lewis_Carlsbad_Desalination_Plant

The Claude “Bud” Lewis Carlsbad Desalination Plant is a desalination plant in Carlsbad, California, north of the Encina Power Station. The San Diego County Water Authority (SDCWA), the recipient of the fresh water produced by the plant, calls it “the nation’s largest, most technologically advanced and energy-efficient seawater desalination plant.” Opened on December 14, 2015, the entire desalination project cost about $1 billion for the plant, pipelines, and upgrades to existing SDCWA facilities to use the water.

Says that it took us 14 years to do ours from permitting to activation, though, so unless Mexico can expedite that, they probably wanna get moving on that.

EDIT: It sounds like they’ve been trying to build one, and they indeed consider it to be urgent:

https://voiceofsandiego.org/2024/07/29/border-report-rosarito-desal-plant-could-finally-get-off-the-ground/

Border Report: Rosarito Desal Plant Could Finally Get off the Ground

State officials say the plant’s first phase would secure the water supply in Tijuana and the surrounding region for the next two decades.

As water shortages loom in Baja California, the state’s plans for a desalination plant are back on track after years of delay.

An undeveloped 50-acre plot next to a power plant in northern Rosarito Beach – envisioned as the site of the proposed desalination facility – is now in Mexican government hands. By the end of the year, the state of Baja California expects to invite prospective developers to submit bids.

Supporters say it’s not a moment too soon. Global warming threatens to reduce future deliveries from the Colorado River, the state’s main water supply. Like San Diego, Baja California’s coastal regions are largely dependent on the Colorado River for water, and authorities face growing pressure to find alternate sources.

Some Tijuana residents have already faced water shutoffs in recent years. A former director of the state water agency in Tijuana warned recently that in the next five years, the supply won’t meet the city’s needs.

A point person on the desalination project has been the state’s treasury secretary, Marco Antonio Moreno Mexia. In Mexicali last week, he told reporters that in its initial phase, the  plant would have the capacity to produce up to 2.2 cubic meters per second of drinking water, or about 50 million gallons daily–the size of the Poseidon desalination plant in Carlsbad.