In South Africa 98% of all potential raw water sources are already allocated for use. Increasing urbanisation and demand for safe sanitation place heavy demands on our water resources. The Department of Water & Sanitation estimates that R7-billion in potable water is lost annually. That amounts to 36% of the clean drinking water supply!
Dr Jo Barnes, epidemiologist and senior lecturer at the Stellenbosch University (SU) Faculty of Health Sciences, was the guest speaker at the Winelands Chapter of Mensa SA in Somerset West last month.
Dr Barnes endeavours to drive actions and create awareness about the growing problem of urban water pollution, sanitation and related health issues through her research and community interaction, and as speaker on many public forums.
She explored the current water shortage in her presentation:
Dr Barnes holds degrees in mathematics, epidemiology and community health. Her major research interests are water-related diseases, water pollution, and sanitation, and she has extensive knowledge of the river water quality in the area, as well as pollution sources. She is a recipient of the Order of the Disa of the Western Cape Province, and is an associate of the SU Water Institute.
A wonderful presentation to Mensa, thank you Dr Barnes.
Would harvesting of rainwater come into the definition of ‘raw water’? I have a deep concern, one that very few seem to share, that collecting and storing the rainwater that falls on our rooves could and would at a slightly larger cost, but zero running costs, in large measure supply our need for water in the cities; that would free up water for agriculture and industry.
Throw in the losses due to reticulation and the outlay would be very similar.
You mention that it costs R15 billion to set up a 450 ML desalination plant. Based on our underground reservoir, I estimate that 50,000 rather larger 45,000 litre reservoirs would cost 25 billion, with almost zero running costs and none of the losses, disposal of concentrated saline and other problems you mention. Building them would create employment for a lot of people, and save our foreign reserves. We have the bricks and cement, sand and stone right here in SA.
Below ground the water is icy cold even in summer; the E Coli count in our reservoir is zero.
Why is large scale rainwater harvesting in individual homes and business properties not coming into the equation; our reservoir has failed for only one month in six years at the height of the drought.