Innovative Rainwater Harvesting Technologies

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The term ‘rainwater harvesting’ is usually taken to mean the immediate collection of rainwater running off surfaces upon which it has fallen directly. Although some definitions limit themselves to roof surfaces, in this project, rainwater harvesting includes surface runoff and artificial media catchments.

In arid and semi arid regions where there is water scarcity, small-scale collection infrastructure can contribute greatly to the volume of freshwater available for human use. In these regions, the rainfall received may be little but usually, intensity is high and often shows seasonality. Because of this, runoff and river flows can be abundant for brief periods and non-existent throughout the rest of the year. The intergovernmental panel on climate change (IPCC) predicts that between 75 and 250 million people will be exposed to increased water stress over the next decades. The same report also affirms that the risk will be much more in developing countries including Africa (ACCES 2011). Climate change leads to water scarcity, drought and food insecurity which inturn hampers economic productivity. The negative impacts of climate change are more serious in communities who have no adaptation mechanisms and resilient survival strategies.