Fog Catching: A Natural & Sustainable Water Source
Fresh water is a rapidly dwindling resource. Throughout the world, the increasing population is placing more and more demands on a smaller supply of water. Rainfall patterns are becoming less reliable and rivers and lakes are drying up. About 2/3 of the world’s population currently experiences water scarcity for at least one month per year, many for much longer. In some areas, water may be trucked in, but the price is outrageously high. Desalination, converting saltwater into fresh water, is a solution but not one that’s economically viable at this time.
Lima, Peru is a desert city of 10 million people located on the Pacific coast of South America. One of the driest capital cities in the world, it gets less than one inch of rain per year. However, it’s shrouded in fog for six months of the year, from April to September. Industrial engineer Abel Cruz devised a way to catch the fog and utilize it as a water source. His idea stemmed from the ancient method of placing containers underneath trees to capture water droplets from the leaves. His organization erected more than 100 nylon nets on the outskirts of Lima. As water vapor is caught in the nets, it condenses into liquid water and drips into a holding tank. With just two poles and a net, the simple device can be a significant source of water, collecting between 50 to 100 gallons daily.
Cruz has helped install over 2000 nets in communities across Peru, as well as in Bolivia, Columbia and Mexico. In rural areas without much air pollution, the captured water is drinkable. In polluted Lima, the water isn’t drinkable, but can be used for bathing or farming or boiled for cooking. With enough water to grow crops or raise animals, communities have been transformed.
Fog catching could help to ease the pressure on water resources in cities around the world. On the coastlines of the United States, New Zealand and Namibia there are a number of cities that are regularly covered by fogs that could be tapped for water. Meeting the needs of rural populations with traditionally low water consumption is one thing; meeting the needs in places where people consume much more is something else entirely. But in our changing world, an easy and inexpensive solution can certainly help.