Assessment of water scarcity and its impacts on sustainable development in Awash basin, Ethiopia

Equitable access and rational use of water resources is important to cope with water scarcity. The optimal allocation of limited water resources for various purposes is required for sustainable development. Awash river basin is one of the most utilized river basins in Ethiopia. There is increasing demand for water due to recent population growth in the basin because of Urbanization. Excessive water abstraction without properly assessing the available water resources in the basin contributes to water scarcity. The basin exhibits two extreme hydrological events, flooding and drought at different seasons of the year. This paper mainly focuses on surface water resources assessment of the Awash basin, and the temporal gap between water supply and demand. The paper also discusses the impacts of these gaps on sustainable development and suggested few recommendations to minimize it. Using SWAT model, the annual average surface water available is estimated around 4.64 Billion Cubic Meters (BCM) as compared to the estimated demand of about 4.67 BCM in the basin for 1980–2012. This shows that on an average, the demand exceeds the availability by 0.03 BCM during the study period. Seasonal water deficit is even serious. A detailed seasonal analysis for the last 2 years (2011–2012) shows that the demand exceeds supply by 1.27 and 2.82 BCM during December–April of 2011 and 2012, respectively. However, there is a surplus supply of 1.67 and 3.16 BCM during June–September months of the same year.