A picture taken on May 28, 2013, shows the Blue Nile in Guba, Ethiopia, during its diversion ceremony. Ethiopia has begun diverting the Blue Nile as part of the Grand Ethiopian Renaissance Dam hydroelectric project. — AFP/VNA Photo

ADDIS ABABA — Ethiopia said on Tuesday that its first-year target has been reached for filling a mega-dam on the Blue Nile River that has stoked tensions with downstream neighbours Egypt and Sudan.

The announcement from Prime Minister Abiy Ahmed's office indicated that enough water had accumulated to enable Ethiopia to test the dam's first two turbines – an important milestone on the way toward actually producing energy.

But it risked drawing the ire of both Cairo and Khartoum, which had insisted that a trilateral agreement on the dam's operations be reached before Addis Ababa began impounding water in the dam's reservoir.

"It has become evident over the past two weeks in the rainy season that the GERD first year filling is achieved and the dam under construction is already overtopping," Abiy's office said in a statement, using the acronym for the Grand Ethiopian Renaissance Dam.

The project has been a source of tension in the Nile River basin ever since Ethiopia broke ground on it in 2011.

Egypt and Sudan view the dam as a threat to vital water supplies, while Ethiopia considers it essential for its electrification and development.

Ethiopia's announcement came as African leaders held a virtual meeting on Tuesday to try to resolve the dispute, a process that was being overseen by the African Union.

In a Twitter post after the meeting, Abiy said it had been "fruitful" and that there was a "common understanding reached on continuing technical discussions on filling".

The office of Egyptian President Abdel Fattah al-Sisi also said an agreement was reached "to continue negotiations" with an eye toward developing "a comprehensive deal... on the use of the Nile waters between the three countries".

In a statement earlier Tuesday, African Union Commission Chairperson Moussa Faki Mahamat said it was "absolutely necessary" that Ethiopia, Egypt and Sudan "come to an agreement that preserves the interest of all parties".

Turbine testing

Ethiopia has long intended to begin filling the dam's reservoir this month, in the middle of its rainy season.

Last week Ethiopian officials acknowledged that water was gathering in the dam's reservoir, though officials said this was a "natural" part of the construction process.

The statement from Abiy's office Tuesday did not specify whether the first-year target had been hit through a "natural" process or through other steps to expedite filling.

An official at the dam site stressed on Tuesday that the dam's culverts remained open and water continued to flow downstream.

"There is no closure, nothing," the official said, adding that heavy rains meant water exceeding the capacity of the culverts was "accumulating".

The reservoir has a capacity of 74 billion cubic metres, though the target for the first year was considerably less than that, at 4.9 billion cubic metres.

The goal is to impound an additional 13.5 billion cubic metres in the second year. — AFP