Groundwater is the only water resource across the "hyper" arid Eastern Sahara. Management
of this resource is imperative for the sustainable development approaches. A 3D GIS-based
groundwater flow model for the Nubian Sandstone Aquifer System (NSAS) was developed to simulate
the groundwater management options for the different development areas/oases within the aquifer,
and to predict the environmental impact of the present and future groundwater extraction schemes on
the whole system. Based on the actual and planned extraction rates of the NSAS, five extraction
scenarios were suggested to investigate the most feasible groundwater management option in terms of
the economic lifting depth until year 2100. The model was calibrated and validated under the transient
conditions. The calibrated model was then used for the prediction simulations and the local modeling.
The results of simulating the present extraction rates of the NSAS until 2100 showed that the free
flowing phenomenon will disappear all over the modeled area. At this simulation time, a groundwater
volume of 354 km³ will be extracted from the aquifer storage. Scenario 3 was found to be the optimal
groundwater management option that meets the development ambitions and in the same time keeps
the safe economic lifting depth as well.