Africa Water, Sanitation & Hygiene Africa water, Sanitation May-June2015 Vol. 10 No.3 | Page 16

Rainwater Harvesting Rainwater Harvesting What is rainwater harvesting? Rainwater harvesting is the capture and storage of rainwater for landscape irrigation, potable and non-potable indoor use, and storm water abatement. Harvested rainwater can be particularly useful when no other source of water supply is available, or if the available supply is inadequate or of poor quality. Why is there so much interest of late in rainwater harvesting? Rainwater harvesting is enjoying a revival in popularity for two reasons: its inherently superior quality and an interest in reducing consumption of treated water. Rainwater has long been valued for its purity and softness. It is slightly acidic, and is free from disinfectant by-products, salts, minerals, and other natural and man-made contaminants. Furthermore, rainwater harvesting is valued as a water conservation tool to reduce demand on more traditional water supply sources. Are all rainwater collection systems above-ground? While a vast majority of the rainwater collection systems installed are indeed above ground, there are systems available that can be installed below ground surface. Inground storage tanks tend to more expensive than aboveground tanks because of excavation costs and the need to have a more heavily reinforced tank. Why should I be interested in rainwater harvesting when there is so much water already available for my use? Rainwater harvesting provides us an opportunity to conserve and extend our existing resources. Also, rainwater has some intrinsic qualities that should make it attractive to the user. It is pure, soft, and only slightly acidic. It is also free of disinfectant by-products, salts, minerals, and other natural and man-made chemicals that are typically added to water from centralized water supply systems. Plants tend to thrive under rainwater irrigation, appliances last longer because the water is salt-free, and the water tastes good because it is relatively free of chemicals. P .O. Box 41847- 00100, Nairobi, Kenya. Chogoria Road Tel: [phone] Tel. / Fax: [phone] Email: [email protected], [email protected], Website: [email protected] Africa Water, Sanitation & Hygiene • May - June 2015 15