Nets that pull drinking water out of desert fog

In Chile's Atacama, mesh collectors capture fog droplets for drinking and farming, with some hilltop sites reported at up to 12,000 liters a day.

In Chile's Atacama Desert — where some areas see rain only a few times a century and others have never recorded any — communities capture drinking and irrigation water from fog. Mesh structures intercept moisture carried by wind and drain the collected droplets. The technique traces back to nets developed in the Antofagasta region in the 1950s. In 1987, the Chungungo fishing community installed 100 collectors that supplied about 33 liters per day to roughly 300 residents.

Yields vary widely with site and setup. The Atacama Fog Catchers Group reports hilltop collectors that started near 400 liters per day, improved to about 1,000 by 2004, and reached as high as 12,000 liters — though those figures come from the group's president and are not independently verified. A 2023 study in Alto Hospicio, using an internationally standardized fog collector, estimated collection potential of 0.2 to 4.9 liters per square meter per day, suggesting 1,000 square meters of mesh could yield 200 to 4,900 liters daily.

For communities that otherwise depend on trucked-in water or deep wells, fog harvesting offers a low-cost, low-energy freshwater source drawn from something already passing overhead. Water for drinking and for growing food is the most basic need on the list, and the equipment is simple mesh and framing.

What to watch: whether estimated potential translates into steady operational output. Researchers stress that success depends on investment and community organization, not just the physics — and the highest yields remain reports rather than confirmed sustained supply.

Source: Mongabay