Abstract-The main objective of the research is to set a transboundary water management system for the Blue Nile River Basin (within its 16 sub-basins) as well as to create calibrated satellite rainfall data for the Blue Nile River Basin (BNRB). Within the Water Evaluation and Planning (WEAP) model, the simplified rainfall-runoff option has been adopted to determine the runoff of the BNRB, using calibrated satellite rainfall data and adjusted monthly evapotranspiration factors. The WEAP model has been calibrated for the period (1980-1995) and validated for the period (1996-2010) where the simulated and observed flows have been compared at Eldeim, Giwisi, Hawata and Khartoum stations in a monthly time step yielding reasonable values. The results have effectively showed that the simulated flows are reasonable using the Nash-Sutcliffe efficiency criteria (r 2 ) and the Coefficient of Determination (d) of the model performance. The research has found that unmet demands for water resources projects in BNRB may reach more than 50%, especially when considering a high priority for all water resources projects in the basin for all suggested scenarios. For a better BNRB management between Sudan and Ethiopia, it is required to define the priority order for each project within the Basin and to determine allocations of supplies and demands for these projects. The above cannot be achieved without a strong cooperation reaching between riparian countries in place that eventually lead to joint operation of the large storage structures, such as GERD, Karadobi and Mendaya dams.