22 November 2011
The Department of Rural Development and Land Reform is to conduct a pilot project that could see rural communities along the eastern escarpment of Mpumalanga province harvesting fog as a vital water source.
“If the pilot project yields positive results, we will consider a large scale roll-out to feed into local water distribution networks,” department spokesman Eddie Mohoebi said on Monday.
It is hoped the project will alleviate water shortages in South Africa, one of 30 countries with the worst water scarcity in the world. The country’s average annual rainfall of 450mm is nearly half the global average of 860mm per year.
Communities in Cabazane village near Mount Ayliff in the Eastern Cape and Thohoyandou in Limpopo are already harvesting fog and providing clean water for their basic needs.
Simple, electricity-free technology
Fog is caught using a 40 square metre net made of stainless mesh co-knitted with a poly material attached to six-metre-high wooden poles. Gutters, attached to the bottom of the net, catch the water droplets and lead it down into reservoirs. No electricity is needed to operate the plant.
The pilot project in Mpumalanga aims to produce 5 000 to 15 000 litres of water per day through fog harvesting.
According to statistics from the South African Weather Service, Mpumalanga’s weather stations recorded 225 days of fog in 2010. It is the highest number of fog days for all provinces in South Africa.
SA Weather Service senior scientist Dawn Mahlobo said fog was recorded on 82 days at the Kruger Mpumalanga International Airport and 85 days in Ermelo.
The department wants the first fog harvesting plant to be erected either at Piet Retief, Donkerhoek, Madadeni, Shibange or Ntunda.
“At this point in time, it is difficult to determine where exactly the fog will be harvested. The outcome of the feasibility study will determine the areas suitable for fog harvesting technology,” said Mohoebi.
“Other communities along the escarpment will be considered if thick fog appears for 90 days or more for a few hours at a time and is accompanied by strong wind. The sites should also be at least 1km above sea level,” Mohoebi added.
The bids for Mpumalanga’s pilot project closed last week. The pilot project will commence a month after a service provider is appointed, with the contractor training community members to operate and maintain the system.
The department hopes the project will provide access to clean water and enhance local economic development with job creation in installing and maintaining fog water harvesting technology, and establishing small gardens for community.