The project also has been opposed by the non-profit International Rivers, with Terri Hathaway, the organization’s director for its Africa program, previously quoted as saying Gibe III is "the most destructive dam under construction in Africa." Hathaway also said it would condemn "half a million of the region's most vulnerable people to hunger and conflict.”

In a related development, Ethiopia rejected in March an attempt by neighboring Egypt to halt construction of the 10-million-cu-m Grand Ethiopian Renaissance Dam, located on the Blue Nile, until a fresh study is carried out on the impact of the project.

Egypt says the dam will reduce the flow of the Nile, on which the country relies for almost all its water-supply needs.

“What we are doing is fair and very acceptable. … We do not need another study,” said Alemayehu Tegenu, Ethiopia’s water minister.

Earlier, Ahmed Mostafa said his country draws only 55.5 billion cu m of water from the 2,000 to 2,500 billion cu m of water in the Blue Nile, giving each Egyptian access to 620 cu m of water per person, “way below the international standard of 1,000 cubic meters for every citizen per year.”

However, Zadig Abraha, deputy general director of the Grand Ethiopian Renaissance Dam, says Ethiopia is proceeding to complete the project and hopes to generate electricity in 17 months. He said in a media interview in March that the project presents “the golden age of our history as far as economic development and public participation is concerned.”

“If we are to meet the power demand, we have to construct these mega projects,” the deputy general director said.

This article was updated on April 30, 2014.