Ethiopians have celebrated the inauguration of Africa's biggest dam as a defining moment in the country's history, even as downstream states warn of "grave consequences" without guarantees on how water flows will be managed.
Construction of the Grand Ethiopian Renaissance Dam has "fuelled nationalist fervour in Egypt, which relies on the Nile for almost all of its water needs", said the Financial Times, but "also in Ethiopia, where use of the river is seen as a sovereign right".
For Ethiopians, Africa's largest hydroelectric plant is seen not just as a "pile of concrete in the middle of a river, but as a monument of their achievement", Moses Chrispus Okello, an analyst with the South Africa-based Institute for Security Studies think tank, told the BBC.
When fully operational the dam is expected to produce more than 5,000 megawatts of energy, enough to provide electricity for more than half of Ethiopia's 120 million people.
For Egypt, "the dam represents the opposite of Ethiopia's hopes and ambitions", said the BBC. In a country that relies almost entirely on the Nile for its water, there are "fears that the dam could sharply reduce the flow of water to the country, causing shortages".
Ethiopia's Prime Minister Abiy Ahmed recently sought to downplay these concerns, stressing that the dam "is not a threat". However, it does mark a decisive break from the colonial-era deal negotiated by Britain in the 1920s that guaranteed Egypt about 80% of the Nile's water, as well as from a 1959 bilateral treaty between Egypt and Sudan governing the use of the river's resources. | 
