CaliToday (28/10/2025): In the desolate landscapes of Chile’s Atacama Desert, one of the most arid regions on the planet, rain is often just a distant memory. Yet, in this parched land, a "hidden river" flows through the sky. A thick, coastal fog, known locally as the camanchaca, regularly rolls in from the Pacific Ocean, and for local communities, this mist is a life-saving source of water.
The technology that unlocks this resource is as simple as it is ingenious: fog nets.
These systems, also called fog catchers or collectors, are large mesh screens stretched between poles, positioned in coastal and mountainous areas like Alto Patache and Falda Verde. The design is a brilliant example of biomimicry, emulating how desert beetles and plants capture moisture.
The process is deceptively simple. As the dense, moisture-laden fog is pushed by the wind, it passes through the fine mesh. The tiny, suspended water droplets in the fog are trapped by the net's fibers. As more droplets collect, they coalesce—merging into larger, heavier drops. Gravity then takes over, and the water trickles down the screen into a series of collection channels at the bottom.
From these channels, the water is piped to storage tanks. After minimal filtration, this harvested water is clean, safe to drink, and ready to use.
The results are nothing short of revolutionary. A single square meter of mesh can capture between 3 and 15 liters (0.8 to 4 gallons) of fresh water per day, depending on the fog's density and local wind conditions.
For the indigenous and rural communities of the Atacama, this technology is a game-changer. It provides a reliable, decentralized, and sustainable water supply, liberating them from their dependence on rapidly depleting groundwater aquifers or expensive, carbon-intensive water transported by trucks.
This is the trifecta of sustainable solutions:
Environmentally Friendly: The system is entirely passive, requiring no energy to operate.
Inexpensive: The materials are cheap and readily available.
Low Maintenance: The nets are durable and require little more than periodic cleaning.
The success of the Chilean fog catchers has not gone unnoticed. The Atacama has become the proving ground for a technology that is now being researched and implemented in other fog-prone arid regions across the globe. From the mountains of Morocco and Peru to the dry coastal lands of South Africa, this simple mesh net is proving that sometimes, the most profound solutions to our greatest challenges are floating in the air all around us.