In numerous places where rain is scarce and clean running water is a luxury, fog harvesting is bringing relief to many people.
Designed to catch moisture from the air, the fog harvesting system involves a series of sheets or “fog nets” that are stretched between pillars and hang over a catchment gutter collecting droplets. The mesh sheets pick up the tiny droplets, which then run into a gravity-fed system through a filter into a storage tank for use.
In recent years, a number of areas in South Africa have tried this water-collection method. Running water in Tshiavha village in Limpopo province is rare, but its mountainous landscapes and misty climate make the village one of the few areas where fog can be captured. Erected at the Tshiavha Primary School in 2007 with the help of the University of Pretoria, the fog trapped in the nets provides up to 2,500 litres of water on a good day. According to principal, Lutanyani Malumedzha, the water is clean and safe with no chemicals added to it, and has significantly improved the children’s health and reduced the outbreak of waterborne diseases.
Residents of Cabazane, a remote village in the Eastern Cape of just 180 residents, harvest up to five litres of water per day produced by every square metre of fog net, at 700 sq metres the system can provide thousands of litres of water daily, depending on conditions.
In the islands of Cape Verde off the east coast of Africa, fog nets set up in 2005 can collect up to 4,000 litres of water a day in good conditions. Fog harvesting projects are also running in small or remote communities in Morocco, Chile, Peru, Nepal and Guatemala because they are inexpensive to set up. The Cape Verde project cost around $12,000, and the Cabazane nets went up for $40,000, as opposed to the millions it would take for a regular municipal water system.
Although South Africa’s water quality is rated among the best in world, rural communities lag behind when it comes to having running water. Successful fog harvesting projects are also running in Lepelfontein in the Northern Cape and at Lusikisiki in the Eastern Cape. This year the Department of Rural Development and Land Reform plans to initiate a similar pilot fog harvesting project for poor communities along Mpumalanga’s eastern escarpment. Possible sites have been identified near Piet Retief, Donkerhoek, Madadeni, Shibange and Ntunda. – Melissa Jane Cook