10. The water that leaves the rooftop may be 65 – 90% of the water that falls on it Roof material absorbs some water More water loss if roof is flat Evaporation losses
13. How much water can we harvest? Rain Water Collected From Both Sides of the Roof W Rain Water Collected From one Side of the Roof Amount of rainfall (mm) x = W Catchment Area (m2) Volume of water received (Litres)
14. Transportation Pipe size is calculated based on peak flow rates (rooftop area and peak rainfall rate) Gutter (open on top) Downtake pipe (cylindrical) PVC pipes preferred. Do not use lead pipes
17. Filters Gravel Sand Inlet Out flow Over flow Gravel Recharge tank Filter Storage tank Down take pipes First flush Check and clean filters before and after each rainy season Make your own filter with sand, charcoal and gravel Or Buy a filter off the shelf
24. What can we use the rain water for? If used for drinking, it is absolutely necessary to check water quality in a lab and treat as required
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30. How much water can we harvest? Rain Water Collected From Both Sides of the Roof W Rain Water Collected From one Side of the Roof Amount of rainfall (mm) x = W Catchment Area (m2) Volume of water received (Litres)
31. Transportation Pipe size is calculated based on peak flow rates (rooftop area and peak rainfall rate) Gutter (open on top) Downtake pipe (cylindrical) PVC pipes preferred. Do not use lead pipes
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33. Filters http://www.rainyfilters.com/rainwater.aspx Gravel Sand Inlet Out flow Over flow Gravel Recharge tank Filter Storage tank Down take pipes First flush Check and clean filters before and after each rainy season Make your own filter with sand, charcoal and gravel Or Buy a filter off the shelf
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39. What can we use the rain water for? If used for drinking, it is absolutely necessary to check water quality in a lab and treat as required
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