Sanddam.org

Large parts of the world cope with increasing water scarcity during periods of low rainfall and drought. This is further augmented by the impacts of climate change on spatial and temporal rainfall patterns, while growing populations increase the overall water demand. Overcoming periods of low rainfall and drought will thus become increasingly difficult. Maximizing storage of precipitation and runoff will be one of the main challenges in coming decades to secure water availability.

Decentralised storage of water is an important strategy in semi-arid and arid regions outside the reach of perennial rivers, springs, deep groundwater or other water sources. Building sand dams in seasonal rivers is a successful example. Upstream of the dam sand accumulates, resulting in additional groundwater storage capacity of riverbed and –banks. This reservoir fills during the wet season, preventing quick runoff of valuable rainwater out of the catchment and out of the reach of the community. Water availability during dry seasons is prolonged and generally guaranteed. The quality of the water is protected against evaporation and contamination. Water quality is even improved through natural filtration in the soil. The technique of sand storage dams is not new: storage of rainfall and runoff, including sub-surface storage, for beneficial use has been applied since 9,000 BC.

RAIN Foundation and Acacia Water, have initiated a project to introduce sand dam technology in Ethiopia, based on experiences and expertise from SASOL (Sahelian Solutions). SASOL has successfully constructed over 500 dams in the Kitui District, Kenya. This initiative was awarded the Swiss Re International ReSource Award for Sustainable Water Management in 2007.






Sand storage dam during the wet season