Ethiopia’s second filling of its disputed Nile dam this summer will involve a much smaller amount of water than previously announced due to construction delays, experts said on Wednesday.
The reduction – from 13.5 billion cubic metres to around 2bn – is likely to defuse some of the tension between Ethiopia and downstream Egypt and Sudan.
They have repeatedly stated their opposition to the second filling without first reaching an agreement on the dam's operation.
The reduced filling could have a positive impact on negotiations for a comprehensive resolution of the dispute over the Grand Ethiopian Renaissance Dam, or Gerd.
“Egypt and Sudan now have a year in which they can chart a new strategy,” said Hany Raslan, a senior Africa expert from Egypt’s Al Ahram Centre for Political and Strategic Studies research institute.
The middle section of the dam must be built up to 590 metres above sea level if Ethiopia is to store 13.5bn cubic metres in July and August, the peak of the flood season.
That section currently stands at about 560 metres above sea level and it is virtually impossible to raise it to the required height before the flood season comes to an end, Mr Raslan said.
There has been no official word from Addis Ababa on the volume of water to be stored in the second filling, with officials insisting only that it will go ahead as scheduled.
Egypt and Sudan have been pressing Ethiopia for years to enter a legally-binding deal on operating and filling the dam, as well as mechanisms to deal with future droughts and disputes.
Ethiopia, which has mostly dealt with the issue as a matter of sovereignty, says guidelines should suffice.
The last round of talks broke down acrimoniously in April, with the three nations engaging in hardline rhetoric immediately afterwards and Cairo and Khartoum making thinly veiled threats of possible military action.
"The question of a second filling without an agreement will remain unacceptable to Egypt and Sudan, but I believe there will not be much of an outcry because it will involve much less water," said Attia Essawi, an Africa expert who has been writing on Horn of Africa and Sudan issues for decades in Egypt's state-owned Al Ahram daily.
Last year's first filling involved about 5bn cubic metres and was carried out without Addis Ababa giving Cairo and Khartoum prior notice.
Egypt was not impacted by that filling because the reservoir behind its Aswan High Dam on the Nile was near full capacity, thanks to plentiful rainfall on Ethiopia’s highlands – the source of the Blue Nile, by far the river’s biggest tributary.
Things were different for Sudan, however.
The filling affected farming and disrupted work at water treatment facilities, leaving thousands of homes without running water for days.
"Water treatment plants in Sudan will certainly be affected again by the second filling and the government in Khartoum will condemn Ethiopia for doing it without first co-ordinating the move," said Mr Essawi.
"But, on the whole, the reaction will be much calmer than last year."
Egypt’s foreign minister last month raised eyebrows when he told a television interviewer that his country was “confident” the second filling would not “impact on Egypt’s water interests”.
"If no harm comes to us, then we will continue to deal with matters without escalation," Sameh Shoukry said.
Speaking in another television interview a few days later, he shifted the focus from the impact of the second filling to the perceived audacity of Ethiopia taking unilateral action.
“Surely, if the second filling is done unilaterally and without a comprehensive deal on the filling and operation of the dam … then Ethiopia will be in breach of international law,” said Mr Shoukry, who travelled to Khartoum on Wednesday with Egypt's Water Resources Minister Mohamed Abdel Atti for talks on the issue.
Sudan and Egypt have forged close military ties in recent months, launching a series of joint war drills and signing a military co-operation agreement.
The war games appeared designed to send a message to Ethiopia that military action was on the table if an agreement remained elusive.
The message was not lost on Ethiopia, whose military chiefs have been speaking to local media about beefed up air defences at the dam's site, which is only 20 kilometres from the Sudanese border.
But experts say Egypt continues to view the military option as a last resort because of the regional repercussions and the questions over how effective such action would be..
Sudan, for its part, has little appetite for fighting a neighbour with which it maintains close social and cultural ties.
Egypt, meanwhile, has been trying to woo sub-Saharan Nile basin nations, offering military and security co-operation deals, plus technical support in a wide range of fields.
These efforts are partially designed to pull them away from Ethiopia's sphere of influence in the region andsecure their goodwill in the event of military action over the Gerd.
President Abdel Fattah El Sisi has said diplomacy was Egypt’s preferred path to resolve the dispute, but warned that Cairo was not prepared to be bogged down in “indefinite” negotiations.
No one should presume to be beyond the reach of the Egyptian military, he warned in March.
But US involvement in talks can’t be relied on to assist Egypt, Mr Raslan said. Ending the humanitarian situation in Ethiopia’s Tigray region, where a civil war between separatist rebels and federal troops has raged since November, is a higher priority.
“The Americans are primarily concerned with preventing Ethiopia from breaking up, not with the dispute over the dam,” said Mr Raslan.
“They are also pressuring Egypt not to take military action against the dam.”