Global demand for lithium is expected to increase by nearly 500% over the next few decades, as countries invest more in batteries and electric vehicles meant to reduce their carbon footprint. But lithium also brings its own environmental concerns, putting stress on freshwater supplies in the desert areas where the mineral is most common.

Measuring water availability for lithium extraction is still unreliable, especially in South America’s high-altitude Lithium Triangle, home to the world’s largest deposits. More accurate models need to be applied there so mining operations don’t use more water than is available, one recent study argued.

If mining operators continue with their current water usage, it could exacerbate the region’s scarcity problem and lead to the destruction of ecosystems and a crisis for nearby communities.

“The conventional wisdom is overestimating the amount of water by at least an order of magnitude,” said David Boutt, who co-authored the study in Communications Earth and Environment. “We found that all but one of the 28 basins in our study should be classified as ‘critically water scarce,’ even without incorporating current, to say nothing of future, demands on the water supply.”

The Lithium Triangle spans more than 414,000 square kilometers (160,000 square miles) across Chile, Argentina and Bolivia, where an arid climate and water-trapping basins have helped form an estimated 98 million tons of lithium deposits.

Mining the lithium involves extracting salty brine and storing it in large evaporation ponds where the sun removes the water, leaving behind a solution that is then chemically treated to produce either lithium carbonate or lithium hydroxide, both used to make batteries.

One ton of lithium needs around 2 million liters (528,340 gallons) of water. In Argentina’s Salar de Olaroz, the evaporation ponds cover 12 km2 (4.6 mi2) while in Chile’s Salar de Atacama, the ponds cover 49.9 km2 (19.3 mi2).

To make sure there’s enough water available, lithium mining companies use different kinds of hydrological models that measure variables like the total volume of water flowing through a river and how much rainfall and snowmelt soaks into the ground.

But many models assume that the watersheds in the Lithium Triangle are more open and wetter as in other parts of the world, where river basins flow into the ocean and most water is channelized. Rivers in the salt flats don’t flow into the ocean and they see very little precipitation.

As a result, the models can sometimes assume there will be more water available than there actually is, leading to long-term risks of overuse and scarcity for nearby communities.

“These models are way overpredicting discharge in these systems, and that has an important impact on designing a lithium project around a certain amount of freshwater being available,” Boutt said.

Without that water, native vegetation could die and would no longer act as a sponge that prevents water from filtering deeper into the ground, Boutt explained. It also wouldn’t be available for grazing species that rely on it for food.

If the water seeps deeper into the ground, it could also deplete lagoons and wetlands that serve as freshwater sources for communities living near the lithium deposits.

The study proposed its own model that more accurately accounts for the specific conditions of the Lithium Triangle, while calling for more weather stations, hydrological stations and policies that make it easier to share information between governments.

“When you don’t have that fundamental information, a lot of uncertainty creeps into the analysis,” Boutt said.

Banner image: The protected Tebenquiche Lagoon in Chile.Photo courtesy of Wikimedia.

Citation:

Kirshen, A. B., Moran, B. J., Munk, L. A., Russo, A. A., McKnight, S. V., Jenckes, J., … Boutt, D. F. (2025). Freshwater inflows to closed basins of the andean plateau in Chile, Argentina, and Bolivia. Communications Earth & Environment, 6(1). doi:10.1038/s43247-025-02130-6

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