Watering your garden with fog

You might say that the Peruvians Without Water Movement (El Movimiento Peruanos sin Agua) has its head in the clouds. Literally. 

Because that’s where the fog is, and fog is a low-cost and accessible way to help the 3.8 million Peruvians who don’t have access to water.

Lima is dry. It’s home to more than 10 million people but gets less than an inch of rain a year. Two million residents don’t have access to the municipal water network, and that includes many rural migrants who can’t farm any more because of climate change.

But the thick grey fog that covers the city most of the year, caused by damp Pacific winds meeting hot sub-tropical air along Peru’s coast, now helps many poor families in the Peruvian capital who can’t afford to buy trucked water. It is often far more costly for them than it is for people in richer parts of the city. 

Industrial engineer Abel Cruz moved to Lima in 2005 but grew up in mountainous Cuzco. His family used to collect droplets of water from banana tree leaves for washing and to grow tomatoes, lettuce, fruits and plantain. He and his father built a kind of canal with the leaves to transport the water before turning to bamboo that was cut in half.

Fog collection wasn’t new. Chilean and Canadian researchers had explored it in Chile starting in 1985, and later expanded to Ecuador, Dominican Republic, Guatemala, Haiti, Namibia, Oman and several places in Peru, including Lima.

“Fog collection can be a sustainable water supply for as long as the village and the local NGO maintain the system,” says Fogquest, the Canadian nonprofit that was involved in these early experiments and is currently involved with fog collection projects in eight countries. 

“This could be 10, 100 or 1000 years. The durability of a project will depend on the human component. The meteorological conditions that produce the fog are determined by large scale circulations in the atmosphere that change little over long periods of time.”

Cruz and residents from communities around Lima teamed up with scientists and began erecting fog nets on hillsides around Lima. Tiny droplets condense on mesh netting strung up on hillsides, and dribble down into pipes that carry the water into containers where it can be used to irrigate crops or even as drinking water. Each net can capture between 200-400 litres of fresh water every day

Building one of the water reservoirs. Green Desert Project

Cruz has helped to install 600 fog catchers across Lima and more than 2,000 fog catching nets in eight rural communities across Peru, as well as in Bolivia, Colombia and Mexico. In June, the project signed an agreement with the Mayor of Lima to install 10,000 more fog catchers in the hills surrounding the city over the next four years. 

The municipality said the project has the potential to “reforest, create ecological lungs, ecotourism and at the same time provide water for human consumption, for bio-orchards, botanical gardens, washing clothes, utensils and more.”

El Movimento says it develops water systems for the common good. “We don’t bring water,” it says.”We bring hope and development opportunities for those in most need.” It describes itself as a “non-profit organization that provides access to quality water for vulnerable sectors through innovative comprehensive solutions for the generation of economic and productive activities under a sustainable model that reduces environmental impact.”

German conservationists Anne Lummerich and Kai Tiedemann had noticed that the few remaining bushes and trees in the hills were covered with droplets that fall to the ground and that this self-irrigation helps support other plants, too. That inspired them to create the ‘Green Desert’ project with the people in Bellavista,one of the villages around Lima.

The planted 800 trees to create a natural fog-catching system that copied this ancient system. In the first year, fog collectors and water reservoirs were installed on the hilltop. The fog water is conducted to the water tanks and used to irrigate the trees. The following winter season,  the trees have become self-irrigating. The fog water they collect now lets the people in villages work in agriculture, which wasn’t possible before when there was no water.

The amazing story of how Bellavista, with the guidance and support of the two scientists, greened their part of Lima is told in an article written by Anne Lummerich. In 2009, two neighbouring villages copied the project idea. “Today – in 2012 – the trees of Bellavista are the only green patch in an area that is still being invaded,” she wrote. “The water problem has not changed; there are just more people in need of water.”


The delicate art of catching fog in the desert National Geographic, Mar. 21, 2023

The ethereal art of fog-catching. BBC Future Planet, Feb. 23, 2020

The Backyard Farmers Who Grow Food With Fog Reasons to be Cheerful, Sep. 18, 2023

The ‘Green Desert’ Project. Anne Lumerich, Alimon

Cover image: SuSanA Secretariat, Wikimedia Commons