Embarrassment apart, it was already no secret that Egypt wanted to stop the largest hydroelectric project in Africa. When Ethiopia completes construction of the dam in 2017, it will stand 170 metres tall (550 feet) and 1.8km (1.1 miles) wide. Its reservoir will be able to hold more than the volume of the entire Blue Nile, the tributary on which it sits (see map). And it will produce 6,000 megawatts of electricity, more than double Ethiopia’s current measly output, which leaves three out of four people in the dark.