Open Access

The Tigray and Afar Water Initiative (TAWI) is a collaboration between the Mekelle University (Ethiopia), the Muenster University of Applied Sciences (Germany) and the Westfalian Wilhelms-University Muenster (Germany). This special initiative is concerned with the rural water supply for the particularly water-scarce regional states of Tigray and Afar in the semi-arid north of Ethiopia. This paper describes a pilot project near the village of Koraro, Hawzen county in the Tigray region and deals with river reaches or creeks which carry water for short periods and only after the longer of two rainy seasons. When these waters run dry, water is still often to be found under the dry beds and is used casually by local people for agricultural purposes. An impermeable wall constructed as a subsurface dam to retain water in the ensuing subsurface micro-reservoir under the bed of such rivers could enable this usage to be intensified and hence enhance the water supply of small local user-groups, while at the same time positively influencing the landscape water balance. Here, the word micro refers to the fact that only the pores of the granular soil of an alluvial river bed are used to store water. Furthermore, storing water underground also avoids the danger of increasing the incidence of diseases such as malaria, a consequence of open water ponds.