WEAP-MODFLOW Dynamic Modeling Approach to Evaluate Surface Water and Groundwater Supply Sources of Addis Ababa City

The integration between WEAP and MODFLOW models coupled via LinkKitchen helps to create a dynamic link between surface water and groundwater supply sources of Addis Ababa city. Possible impacts of natural and anthropogenic stresses on surface water reservoirs volume and groundwater storage have been assessed through water supply scenario analysis. Besides, con- trary to other surface water hydrological models, the unique nature of WEAP adds water demand assessment by simulating Addis Ababa city near future water demand coverage under three population projection scenarios. The water demand projections of Addis Ababa city indicates 100% water demand cover- age will not be achieved for high (4.6%), medium (3.8%) and low (2.8%) population growth rate projections, even with all the emerging and planned water supply projects starting production up until 2025. Supply scenario projec- tions indicate, as surface water reservoirs are highly sensitive to climate change and variability, the city groundwater supply sources will be noticeably affected by the emerging and planned groundwater supply expansion schemes. If ground- water abstraction continues to reach to zero unmet demand, more than 30 meter groundwater level decline can be registered in 2025.