Présentations Colloques

Oral Presentation
2.02
Session 2.02: Groundwater for sustainable water supplies in developing countries
Garoute Aude
Evaluation of groundwater resources in the Tana and Beles sub-basins (Ethiopia) within a framework of River Basin Authorities development and Water Resources Master Plan build-up
The catchment basins of Lake Tana and the Beles River in Ethiopia have been identified as a priority area for development, especially in terms of improving access to water. The Ethiopian government has thus decided, through specific public investments, firstly, to create two River Basin Authorities (TaSBO and BeSBO) based on the French model of basin authorities and, secondly, to increase the knowledge on water resources within these areas with a special focus on groundwater. In this complex context of multiple surface, lake and groundwater interactions and of increasing pressure on water resources, groundwater could represent an attractive alternative to surface water.**The aim of the study performed by Artelia along with its Ethiopian partners Yerer and Geomatrix (2010-2015) was to assess groundwater potential within these catchment basins (covering a total surface area of 30,000 kmC). Using a combination of geological and hydrogeological approaches, test boreholes drilled at depths up to 500 m and isotopic analyses, a series of geological, hydrogeological and groundwater potential maps were produced at scales of 1-250,000 and, locally, 1-50,000. The approach adopted highlighted sectors with high potential that had been hitherto not known. The initial assessment of groundwater potential was confirmed through the setting up of a pilot well field in a target area.**This qualitative leap in knowledge of groundwater will enable the new basin authorities to fully take into account groundwater resources within the water resources master plan that is currently being drawn up. More particularly recently highlighted groundwater resources could be used beneficially for local water supply schemes and small to medium-scale agricultural irrigation schemes.**This study also addresses the redistribution of stakeholder role in relation with the creation of the new basin authorities.**
France