The water resource implications of planned development in the Lake Tana catchment, Ethiopia

The water resources of the Lake Tana catchment are largely untapped. Currently, water resource development is being promoted to stimulate economic growth. This study utilized the WEAP model to determine the likely impact of a number of possible development scenarios on lake water levels. For each scenario, the model was used to simulate water demand in three sectors (i.e. irrigation, hydropower and downstream environmental flows) over a 36-year period of varying flow and rainfall. The simulation results revealed that if all the planned development occurs on average 2198 GWhy−1 power could be generated and 677 Mm3 y−1 of water supplied to irrigation schemes. However, the mean annual water level of the lake would be lowered by 0.44 meters. As well as adverse ecological impacts this would have significant implications for shipping and the livelihoods of local people.