By Lily Bourne
A new study in Chile provides promising evidence that fog harvesting may be viable for capturing water in arid climates. Researchers in Alto Hospicio tested the method–which had previously only been used in small-scale, rural situations–to see if it could provide water for the rapidly expanding settlement. Like many other towns in the Atacama Desert, Alto Hospicio receives almost all of its water from aquifer drill sites over 40 miles away. Because of Chile’s poor water management and megadrought, over 8 million Chileans are under water stress.
Fog collection isn’t a new concept, but has never been attempted on a large scale. Traditionally, fog-loaded wind flows through a suspended mesh sheet, which collects the water and drips into a gutter. In their experiment, researchers found that “in a 100 square kilometer area surrounding Alto Hospicio, between 0.2 and 5 liters of fog water could be harvested per square meter each day.” In a city that receives less than 1 millimeter of rain per year, this collection could be monumental in providing drinking water and irrigation. Researchers surmised that “17,000 square meters of mesh could produce enough water to meet the weekly water demand (300,000 liters) for urban slums.” The collected water could also be used for irrigation of the city’s green spaces and soil-free agriculture.
While fog collection isn’t as simple as setting up a giant mesh fence–water collectors would need to ensure specific geographic and atmospheric conditions, as well as develop storage systems and infrastructure–it does provide hope for developing cities in arid climates. Hopefully, this new research will lead scientists to continue working towards more efficient ways to obtain clean water.