Fog harvesting could alleviate water scarcity in the world's driest area, a new study shows.

In Chile's Atacama dryland, where annual rainfall is less than 1 millimetre, the main source of water is groundwater reserves, which were last replenished between 17 000 and 10 000 years ago. So-called fog harvesting, where the water that makes up the fog is collected and stored, is a promising way to provide much-needed water to an area, the researchers say in a study published in the journal Frontiers in Environmental Science.

In a year-long field study, researchers discovered that up to 5 litres of water per square metre can be collected each day.

Study co-author Virginia Carter Gamberini said the study showed that the use of fog water can be scaled up from a small-scale solution for villages to a practical water resource for cities“.

„Our findings show that fog can be used as a supplementary water supply in arid regions where climate change is exacerbating water scarcity, – she said. Capturing and using water, especially from non-traditional sources such as fog water, is an important opportunity to improve people's quality of life.

Fog collectors usually consist of a net suspended between two poles. Water droplets collect on the net and drain into a gutter that leads to water storage tanks. The collected water could be used for drinking, irrigation and cooking. However, the researchers note that this would require large storage systems, pipeline infrastructure and distribution methods.