The bitter dispute over Africa’s largest dam

FOR BIRUK NEGAFH, as for millions of Ethiopians, the summer rains may bring the climax of a decade’s work. As a high-school student in 2011 he bought 100-birr bonds (then worth $6 each) to help finance the Grand Ethiopian Renaissance Dam, a giant edifice that would span the Blue Nile, the main tributary of the Nile river (see map). At university he donated to fundraisers for the project. Now, like almost all Ethiopians, he eagerly awaits the day—perhaps weeks away—when Ethiopia begins to fill the reservoir. “It’s a national victory,” he says.Half a century in the making, the hydro-electric dam is Africa’s largest, with a reservoir able to hold 74bn cubic metres of water, more than the volume of the entire Blue Nile. Once filled it should produce 6,000 megawatts of electricity, double Ethiopia’s current power supply. Millions of people could be connected to the grid for the first time. More than an engineering project, it is a source of national pride.