There is no quick fix to the global water supply situation. Incidentally, an abundance of fresh water may exist right under our eyes, more specifically in deep coastal aquifers and in submarine aquifers extending far out under the salty oceans. The Kimbiji Aquifer in Tanzania, which extends some 65 km under the Indian Ocean, was discovered in 2005 by Ruden AS Geosolutions. This aquifer is presently being developed to sustain some 1.5 million subscribers of the greater Dar es Salaam area, Tanzania. We believe that the exploration methods used in Tanzania may be applied to the coasts of most of the world’s continents. We have developed a search model based on the principle that the presence of deep coastal freshwater aquifers is probable if:
- Adequate recharge and relief exists in the coastal hinterland
- Transmissive formations with adequate structural control exists between the recharge areas and the coast
- Large permeable reservoirs are present along the passive margin on the continental shelf
We have looked into the water potential of Somalia based on this search model. Virtually all groundwater in Somalia originates from the mountainous Amhar region of eastern Ethiopia. These highlands capture much of the monsoon rains (June to September). The rainwater runoff feeds the Juba and Shebele drainage systems, flowing eastwards through the entire 1000 km of Somalia, towards the Indian Ocean. A proportion of the water infiltrates into underlying aquifers at or near the recharge area. On its way to the coast, the shallow groundwater becomes increasingly separated from the deep underlying aquifers. Meanwhile, a significant portion of the recharged water from the western boundary region is being conveyed along tectonic features such as faults, fractures and karst. The presence of carbonate formations suggests that karst development may be an important feature of groundwater movement in the region. Storage of deep groundwater also occurs in sedimentary basins which serve as reservoirs. There are four principal sedimentary basins in Somalia, and these will be studied in more detail during the next phase of a proposed project.
With the possible exception of the Mediterranean coastline of North Africa, the coastal areas of the African continent display a geological architecture typical of passive margins. In other words, approximately 20.000 km of the African coastline offer the potential for groundwater resources similar to (or possibly better than-) the Kimbiji reference site.