•A single dam construction in the upstream will change hydrologic routine.•There will be maximum energy production in scenario 6 which has 6 reservoirs.•Current irrigation water demand will not be affected by the upstream development. Eastern Nile River Basin (Ethiopia, Sudan and Egypt). This study aims to understand the future water development perspective in the Eastern Nile region by considering the current water use situation and proposed reservoirs in the upper Blue Nile (Abbay) River basin in Ethiopia using a simulation approach. The study was carried out by using a monthly time step and historical ensemble time series data as representative of possible near future scenarios. Series of existing and proposed cascaded water development projects in the upper Blue Nile were considered in the study. The results indicated an overall energy gain in the Eastern Nile region increases by 258%. The upstream country Ethiopia can generate as much as 38200 GWh/year of Energy while the energy production in Sudan increases by 39%. The cascaded developments integrated with existing water resources systems have a performance efficiency of above 92%. This study was an indicative analysis of the potential benefit of upstream Nile development without significantly affecting existing development in the Nile Basin. Further scientific analysis in this direction would help the Nile countries to reach a water use agreement.