|Rainwater harvesting on a commercial farming shed. Picture used courtesy of Helen Gordon, WWF-SA.|
Rain water harvesting (RWH) is increasingly being accepted as a practical method of providing both irrigation and potable water in agricultural and development projects throughout the world.
Enough rain falls on the African continent to supply the water needs for 13 billion people, twice the current world population. However, little of the rainfall is collected or stored through sustainable methods, such as small and large-scale rainwater harvesting.
In South Africa, where the backyards of rural homesteads add up to a whopping 200 000 hectares (i.e. double the current area under smallholder irrigation), the potential impact on food security is more than significant.
The level of economic activity has been shown to double in rural villages with access to more water. This has a direct impact on poverty. Every household with a roof can potentially harvest and store rainwater.
RWH has wide application also in urban and peri-urban areas where the quantity, reliability and quality of piped water are sometimes questioned. Some rainwater might require treatment before it is considered suitable for drinking. So-called “appropriate technology” methods (e.g. as solar water disinfection) provide low-cost disinfection options for treatment of stored rainwater for drinking.
Source: UN Environment Programme (UNEP) “Environmental Food Crisis” report, May 2009; http://en.wikipedia.org/wiki/Rainwater_harvesting; Tsepho Khumbane, Trustee of The Mvula Trust (adapted)
National strategy and government contact
The Department of Water & Sanitation (DWS) , in partnership with Department of Environmental Affairs (DEA), is planning scaled-up implementation of rainwater harvesting as a key component of South Africa’s water resources and efforts to enhance climate resilience. The strategy will provide guidance towards the mainstreaming of RWH in South Africa.
This National RWH Strategy will also help serve as the guiding tool for district and local municipalities to effectively and economically put RWH into practice. Several municipalities now use roof rainwater tanks for domestic purposes. These have been found to be particularly effective when used in conjunction with other water supply options. A resource guideline was developed in 2017/2018 financial year to assist municipalities that are providing rainwater harvesting systems to communities as an interim service or to reduce demand on their water supply systems with best practices. A rainwater harvesting guideline is in the pipeline.
Source: The notes on Rainwater harvesting in the Water & Sanitation chapter of the 2018 government Yearbook on www.gcis.gov.za.
- African Conservation Trust Tel: 031 765 3957 https://projectafrica.com Gardens and RWH for schools
- Applied UV Tel: 021 448 6721 www.applieduv.co.za Applied UV specialises in ultraviolet water disinfection
- Amanzi For Food Tel: 046 603 7276 http://amanziforfood.co.za Training and information providers
- Aquamat Tel: 011 472 1311 www.aquamat.co.za
- ARC–Soil, Climate and Water (ARC-SCW) Tel: 051 861 1172 / 063 011 8849 Fax: 051 861 1027 bothac [at] arc.agric.za Near Bloemfontein, the ARC has developed In field Rainwater Harvesting systems, making cropping viable in areas where people had abandoned crop production.
- Baobab Water Solutions Tel: 082 348 3953 http://baobabwater.co.za
- Builders Warehouse Tel: 0861 335 2739 www.builders.co.za Various water storage devices which can be attached to downpipes.
- DPI Plastics Tel: 011 345 5600 www.dpiplastics.co.za
- Filter Shop Tel: 012 653 8088 www.filtershop.co.za/rain-water-harvesting
- Gauteng Water Heating Tel: 074 865 6923 http://gwhsolar.co.za/water-harvesting/
- Hydrex Water Storage Tel: 011 034 7400 www.hydrex.co.za
- Institute of Natural Resources Tel: 033 346 0796 http://inr.org.za
- Intewa SA Tel: 086 111 4307 www.purerain.co.za
- JoJo Tanks Tel: 013 262 7900 www.jojotanks.co.za
- Kyasol Green Building Solutions Tel: 011 840 0840 www.kyasol.co.za
- MVULA Trust Tel: 011 403 3425 www.themvulatrust.org.za The largest water Non-Governmental Organisation
- Ozone Innovations Tel: 021 854 6400 www.ozoneinnovations.com Ozone Innovations specialises in the design, manufacture and installation of chemical-free ozone and ultra-violet light sterilisation equipment.
- Ozonetek Tel: 021 593 0486 www.ozonetek.co.za “sterilisation the chemical-free way”
- Pennell’s Tanks Tel: 015 516 4981 http://pennellstanks.co.za
- Permaculture2012 Ezio Gori – 083 300 2385 permaculture2012 [at] gmail.com www.permaculture2012.co.za
- Rainbow Reservoirs Tel: 082 809 6516 www.rainbow-reservoirs.co.za
- Rainman Landcare Foundation Tel: 031 783 4412 www.rainman.co.za Rainwater harvesting training
- Rand Water Water Quality Specialist Services, Bulk Water Services Tel: 011 682 0278 gpearson at randwater.co.za www.randwater.co.za (click on the Water Wise logo) Your local Water Board should be able to assist you with advice, publications etc.
- Rhino Water Tel: 041 451 3197 www.rhinogroupsa.co.za
- Rural Integrated Engineering Chris Stimie Tel: 012 804 5014 www.rieng.co.za
- Sustainable.co.za Tel: 0861 661 326 www.sustainable.co.za
- Tizagenix Tel: 082 452 8280 www.use-rainwater.com
- Umhlaba Consulting Group Water for Development Unit Director: Jonathan Denison Tel: 043 721 1554 www.umhlabagroup.co.za
- University of the Free State Department Agricultural Economics Rapids Group Tel: 051 401 2824 www.ufs.ac.za
- Urban Rain Systems Tel: 011 817 3534 www.urbanrainsystems.co.za
- Water Research Commission Tel: 012 761 9300 www.wrc.org.za Studies to assess economic viability, social acceptability and environmental sustainability have shown in-field rainwater harvesting (IRWH) to be a sustainable approach towards empowering rural people to fight food insecurity and improve livelihoods.
- Water Rhapsody Tel: 021 531 9864 www.waterrhapsody.co.za
Rainwater for drinking should be carefully stored and treated prior to consumption. Several technologies exist for home treatment including: ozone sterilisation, UV, distillation. Fairly simple sand filters followed by household chlorine may also be utilised.
For further details, contact Dr Jo Burgess at the Water Research Commission (RWH for domestic use) or Dr Sylvester Mpandeli (for agricultural use).
Websites and publications
- Find information and publications at http://amanziforfood.co.za.
- Various reports on in-field rainwater harvesting and conservation are available from the Water Research Commission. Visit www.wrc.org.za.
- Order online at www.arc.agric.za, call 012 842 4017 or send an email to stoltze [at] arc.agric.za for the following publications, available from the ARC Agricultural Engineering: Water harvesting techniques and Reënvalopvangstegnieke.
- Kejafa Knowledge Works stocks the publication Water Harvesting Techniques. Contact them at 014 577 8006 or visit www.kejafa.com.
- Home Insulations. 2018, February 15. “Rainwater harvesting and storage tanks”. Available at www.homeinsulations.co.za/renewable/rainwater-harvesting-storage-tanks/
- www.harvesth2o.com – the “online rainwater harvesting community” (USA based)
- Find the Info Pak “Collecting rainwater from your roof” from DAFF under the “Resource centre” option at www.daff.gov.za.
- Contact the Environmental Monitoring Group (EMG) for the DVD “Rainwater harvesting – An illustration of what can be done, and is being done at a community level”. See www.emg.org.za.
- “Hoops” are raised earth structures (bunds) constructed as semi-circles on gently sloping land. They are made so that the tips of the bunds or hoops point up the slope and are on the same level with the contour line. The hoops capture rainwater that runs down the slope. Rainwater Harvesting for Increased Pasture Production, CTA Practical Guide Series No 3, an equivalent of the South African Info Paks, is a brochure dealing with the making of these hoops. Visit www.cta.int.
Further excellent sources include:
- Botha, J.J., van Rensburg, L.D., Anderson, J.J., Hensley, M., Macheli, M.S., van Staden, P.P., Kundhlande, G., Groenewald, D.C., & Baiphethi, M.N. 2003. Water conservation techniques on small plots in semi-arid areas to enhance rainfall use efficiency, food security, and sustainable crop production. Report No. 1176/1/03, Water Research Commission, Pretoria.
- Hensley, M., Botha, J.J., Anderson, J.J., Van Staden, P.P. & Du Toit, A. 2000. Optimising rainfall use efficiency for developing farmers with limited access to irrigation water. Report No. 878/1/00, Water Research Commission, Pretoria.
- Kundhlande, G., Groenewald, D.C., Baiphethi, M.N., Viljoen, M.F., Botha, J.J., Van Rensburg, L.D., Anderson, J.J. 2004. Socio-economic study on water conservation techniques in semi-arid areas. Report No. 1267/1/04, Water Research Commission, Pretoria.
- Water resources management in rainwater harvesting: An integrated systems approach includes case studies of villages / farm workers who catch rainwater for a variety of purposes.
- Rainfed Farming Systems (eds Tow P, Cooper I, Partridge I, Birch C). Springer, The Netherlands. Find the chapter “Rainfed farming systems in South Africa” by Hardy MB, Dizba L, Kilian W and Tolmay J.
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