Harvesting Fog Provides Drinking Water, Food to Peruvian Slums

In Lima, Peru, more than 1.3 million people have no access to drinking water. The citizens without it are in the poorest areas, where water trucked in can cost nine times as much as it does in richer areas. So, citizens have had to either make do without running water, or, with the help of a German NGO, make dew into drinking water.

The Telegraph reports on one slum in particular, Bellavista del Paraiso. With 200 residents in need of water, the mayor of the slum stated, “We are the very first to have fog-catchers in Lima’s poor neighborhoods…We have five panels that are eight metres by four metres (26 feet by 13 feet),” perched on the mountaintop above, he explained. “With them we are able to collect up to 60 litres per night in wintertime.”

The water is used for drinking and cooking, but also to irrigate small vegetable gardens. So the fog nets are bringing a much needed resource right to the kitchen steps of the citizens. While the nets cost around $800 each, and water purifying tabs are also required, the pay-off is far greater with citizens able to drink and raise food with the fog water.

German biologists Anne Lummerich and Kai Tiedemann created the system, and are behind Alimon, the German non-profit organization that has been working to bring drinking water to Peruvians since 2006. The “Green Desert” project is a two-stage affair, involving first human-made fog collectors, and then trees acting as natural fog collectors. According to the organization:

In the first stage fog collectors and water reservoirs are installed on the hilltop. Here we find the best conditions for a high water yield. Tree species which are adapted to aridity and are apt to comb fog are planted between the fog collectors and the water reservoirs. The fog water combed out by the fog collectors is conducted to the water tanks and is used fort the irrigation of the trees.

The second stage starts in the following winter season when the trees are no longer irrigated. Having reached a height of above 1 m they can irrigate themselves now. The taller ones have to do even more: They serve as natural fog-collectors. Channels or funnels are installed underneath them and a part of the water that falls down from their leaves and branches is conducted to the water tanks.

Source – Nov. 12, 2009, Treehugger