African hydrogeology and rural water supply

The widespread development of groundwater is the only affordable and sustainable way of improving access to clean water and meeting the Millennium Development Goals for water supply by 2015. Current approaches to rural water supply, in particular demand driven approaches and decentralisation of service delivery have many benefits to the overall efficacy and sustainability of water supplies, however, problems arise when projects do not take into consideration the nature of the groundwater resources. Different approaches and technologies are required depending on the hydrogeological environment. Sub-Saharan Africa (SSA) can be divided into four hydrogeological provinces: (1) The crystalline basement occupies 40% of the land area of SSA and supports 235 million rural inhabitants. (2) Volcanic rocks occupy 6% of the land area of SSA, and sustain a rural population of 45 million, many of whom live in the drought stricken areas of the Horn of Africa; (3) Consolidated sedimentary rocks occupy 32% of the land area of SSA and sustain a rural population of 110 million: (4) Unconsolidated sediments occupy 22% of the land area of SSA and sustain a rural population of 60 million. Hydrogeological expertise can have significant benefit to rural water supplies by increasing capacity throughout projects by effectively transferring knowledge; by providing authoritative benchmarking, by focused research and by providing accessible advice to planners and policy makers.