The novelty of this study/manuscript is its focus on one of the most tension river basins in the world (region of highest competition on little amount of river flow) and deriving new results that were not reached before, in addition; it gives way forward to the leaders and decision makers in the Nile Riparians that if followed could switch the approaching threat into unprecedented opportunity through regional cooperation/integration and benefits sharing of its transboundary Nile water as a catalyst for other modes of developments intra and inter-basin. The aim of this manuscript is to estimate the additional evaporation losses caused by the new dams constructed as well as planned in the near-future in Ethiopia and The Sudan; namely {Merowe, Rumela & Burdana System, Tekeze, and heightening of the Rosseires dams in the Sudan; The Great Ethiopian Renaissance, and Karadobi dams in Ethiopia}; compared with the status-quo condition which is (Khashm Elgerba, Rosseires, Sennar, and Gebel Awlya dams in The Sudan, and no dams in Ethiopia). It is estimated that higher annual evaporation losses shall significantly occur, an increase from 4.80 to 9.13 Billion m3 (more than doubled); causing more water stress and reduction in the River Nile flow toward its downstream (additional losses could arise from the unilateral filling and operation, seepage, leakage, conveyance and abstraction from those dams’ reservoirs). This manuscript intended—in addition—to inform the political leaders and decision makers in the three Eastern Nile Region countries (Egypt, The Sudan, and Ethiopia) that if half of the additional amount of evaporation losses is conserved; shall be enough water to irrigate more than 0.9 Million Acers of agriculture lands; so that appropriate collective action should be taken in proper timely manner. It is recommended that the three countries to share together the operation of all Eastern Nile Dams, as one integrated system toward more benefits sharing and efficient Nile water utilization.