In the arid Atacama Desert in Chile, one of the driest regions globally, cities rely on ancient underground water sources due to minimal rainfall of less than 0.04 inches annually. However, researchers have discovered an additional straightforward method to address water scarcity.

A team of international researchers in Chile has assessed the feasibility of a water-collection technique reminiscent of science fiction, specifically fog harvesting, which has parallels in Dune and Star Wars, where moisture farmers collect water on Tatooine. According to a study published in Frontiers in Environmental Science, this method could bring significant relief to individuals in underprivileged and informal settings lacking stable water sources.

“Utilizing water from non-traditional sources like fog water presents a crucial opportunity to enhance the living conditions of inhabitants,” said Virginia Carter, a sustainable development expert at the Universidad Mayor and the study’s first co-author, in a Frontiers statement. The study was conducted in Alto Hospicio, a rapidly growing municipality where around 10,000 people reside in informal settlements, with only 1.6% connected to water distribution networks.

The researchers employed simple fog collectors consisting of fine nets or mesh supported by two poles. Moisture in the air condenses into droplets on the material, flowing into a gutter and then a water tank. Although not as advanced as the sci-fi concept of stillsuits that recycle urine into drinkable water, the fog collectors are passive systems requiring no electricity or energy to function.

“By demonstrating its potential in Alto Hospicio, one of Chile’s most stigmatized yet rapidly urbanizing cities, this study lays the groundwork for broader adoption in other water-scarce urban areas,” said Nathalie Verbrugghe, an engineer at Université libre de Bruxelles and another first co-author of the study.

Carter, Verbrugghe, and their team discovered that 38.61 square miles (100 square kilometers) could yield between 0.05 and 1.32 gallons (0.2 and five liters) of fog water per 10.76 square feet (one square meter) per day. The peak months for fog water collection were August and September, with up to 2.64 gallons (10 liters) collected per 10.76 square feet (one square meter) per day.

“This research marks a significant shift in the perception of fog water use, transforming it from a rural solution to a practical urban water resource,” Carter explained.

The researchers estimate that a relatively small area of mesh could collect enough water to irrigate Alto Hospicio’s green spaces. Scaling up the system could provide enough water to meet the weekly needs of the city’s informal settlements. They also suggest fog water could be used for soil-free farming, potentially producing up to 44 pounds (20 kilograms) of leafy greens monthly.

However, the researchers acknowledge some limitations to their analysis, including the need for significant distribution infrastructure and large storage systems for regular use. Other essential prerequisites include fog density, suitable wind patterns, and well-oriented elevated landforms. Additionally, the seasonal nature of fog in many regions must be considered, said Verbrugghe. Carter emphasized that fog serves as a complementary urban water supply rather than a comprehensive solution to water scarcity.

Despite this, the team hopes to encourage policymakers to incorporate this renewable source into national water strategies, which could enhance urban resilience to climate change and rapid urbanization while improving access to clean water, concluded Carter.

Although fog harvesting alone may not solve water scarcity, it represents an innovative and sustainable water collection method that could become an essential tool in desert communities’ water management in the future.