Fog Catchers Harvest Air's Water in Arid Places

July 9, 2009--When dense fog sweeps in from the Pacific Ocean, special nets on a hillside near Lima, Peru, catch the moisture and provide precious water to an area that gets very little rainfall--about half an inch (1.5 centimeters) a year.

The nets stand perpendicular to the prevailing wind, which blows fog into the coarse, woven plastic mesh. From there, drops of fog-water fall into gutters that carry the water to collection tanks.

Since 2006 the nets--built by German conservationists Kai Tiedemann and Anne Lummerich--have helped provide the village of Bellavista, 10 miles (16 kilometers) south of Lima, with hundreds of gallons of water each day during the foggy winter months of June to November.