Portal:Water/Selected page/4

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Sectional view of sand dam
Sand dams. Drought is the most serious natural hazard facing Eastern Africa in terms of severity and frequency of occurrence. The most seriously affected areas are Arid and Semi Arid Lands (ASALS) that face frequent reduction of water or moisture to significantly below the normal or expected amount Pastoralists and agro pastoralists who occupy this vast region barely meet basic water requirements. Consequently they suffer from livelihood losses, hunger, diseases, conflict and internal displacements. The worst affected are women and children who may have to walk all day long in search of water.

Due to limited and unreliable rainfall most rivers are ephemeral seasonal sandy bed streams and only experience heavy water run-off for short periods of time after rain. During such periods of high flows, large quantities of sand are transported downstream while others get trapped on the upstream sides of rocks ledges along the stream. Such sand traps form natural aquifers that are capable of providing clean adequate water if well harnessed. Using appropriate technologies this can be exploited for water storage in the form of sand dams.