Ethiopia has completed the third phase of filling the reservoir for its huge dam on the Blue Nile river, the government said on Friday, a process that continues to irk the country's downstream neighbours Egypt and Sudan. Addis Ababa says the Grand Ethiopian Renaissance Dam (GERD), a billion hydropower project, is crucial to powering its economic development, but Egypt and Sudan consider it a serious threat to their vital water supplies. Ethiopia sees the GERD as the centrepiece of its bid to become Africa's biggest power exporter, with a projected capacity of more than 6,000 megawatts.