After outfoxing Egypt on the diplomatic stage for more than a decade, Ethiopia is set to officially inaugurate one of the world's biggest dams on a tributary of the River Nile, burying a colonial-era treaty that saw the UK guarantee the North African nation the lion's share of its water.
The dam - built on the Blue Nile at a cost of about $5bn (£3.7bn), with a reservoir roughly the size of Greater London - has led to a surge in Ethiopian nationalism, uniting a nation often polarised along ethnic lines and mired in conflict.
Ethiopians may disagree on how to eat injera [their staple food], but they agree on the dam, Moses Chrispus Okello, an analyst with the South Africa-based Institute for Security Studies think-tank, told the BBC.
They do not see it as a pile of concrete in the middle of a river, but as a monument of their achievement because Ethiopians, both at home and in the diaspora, funded the dam's construction. There were waves and waves of appeals for contributions when construction started in 2011.
The government also issued bonds that were bought by companies and workers. So, the sense that all Ethiopians own the dam has grown exponentially, and its inauguration is a source of great pride for the nation, Mr Okello said.
Named the Grand Ethiopian Renaissance Dam (Gerd), it is Africa's largest hydro-electric plant, raising hopes that not only will it meet the 135 million-strong population's energy needs but it will also give the country energy hegemony and boost its foreign currency earnings, the analyst added.
Ethiopia was planning to increase the sale of electricity to neighbouring countries such as Kenya and Djibouti, with ambitions of building a transmission network to cross the Red Sea to sell to Middle Eastern states like Saudi Arabia, he said.
But for Egypt, the dam represents the opposite of Ethiopia's hopes and ambitions. It fears that dam could sharply reduce the flow of water to the country, causing water shortages.
About 93% of Egypt is desert, with almost no people. All of us, 107 million people, live on the Nile, a geologist at Egypt's Cairo University, Prof Abbas Sharaky, told the BBC.
Egyptian civilisation was built on the Nile. The Nile is our life, he added. The academic warns that poverty of water could worsen in Egypt because of the dam.
It is storing 64 billion cubic metres, from water which usually flows to Egypt. This is a very big loss for us. Our average annual share is 55.5 billion cubic metres. We do not have any other source of water, but the Nile, Prof Sharaky said.
He added that the Gerd stores about double the amount of water in the Three Gorges Dam in China, which is the biggest dam in the world in generating electricity.
A former negotiator for Ethiopia over the Gerd, Fekahmed Negash, told the BBC that despite enormous diplomatic pressure and even threats of war from Egypt, Ethiopia had stuck with its plan to build the dam because it was vital to its developmental needs.
This includes providing electricity to the estimated 60% of Ethiopians who do not have access to it, however he noted that this would not be easy as a transmission network would have to be built across the vast country with rocky and mountainous terrain.
Prof Sharaky said that despite the Blue Nile being an international river, Ethiopia took a unilateral decision to build the dam - something it succeeded in doing only because Egypt was hit by a revolution at the time, leading to the overthrow of long-serving ruler Hosni Mubarak.
Egypt was in a very bad situation, without a president, and our military was busy inside the country, he said, adding that the North African state had now taken steps to find alternative sources of water - including building the world's largest water treatment plant, and drilling more than 5,000 wells.
Egypt had also been forced to make changes to its agriculture sector - for instance, by reducing the area for rice cultivation, which is water-intensive, from around two million acres to one million acres, the academic said. If you store 64 billion cubic metres of water that used to flow to Egypt, is it not going to cause harm? Prof Sharaky noted, dismissing Ethiopia's claims that the North African country would not be negatively affected by the dam.
Mr Fekahmed told the BBC that Ethiopia would not return to the era when Egypt was guaranteed a specific amount of water, but it was always open to talks regarding the release of water and the safety of the dam.
Rashid Abdi, an analyst at the Kenya-based Sahan Research think-tank, said the Gerd's completion heralded the end of the deal Britain - the then colonial power - had made in the 1920s to guarantee Egypt around 80% of the Nile's waters.
Britain did it to placate Egypt, and to secure its own interests because Egypt is a strategic state that controls the Suez Canal, the gateway to Europe, Mr Abdi told the BBC.
But Ethiopia is now projecting power, while Egypt's fortunes have declined. It has lost its privileged status over the Nile, he said.
Ahead of the Gerd's inauguration on Tuesday, Egypt's Foreign Minister Badr Abdelatty stepped up his government's rhetoric against the dam, saying that water security was a red line and the dam posed an existential threat to the North African state.
However, Prof Sharaky ruled out the possibility of Egypt going to war with Ethiopia. They are our brothers. We drink from the same water. The Nile is coming from them, he said, adding that Egypt would keep trying to resolve the dispute through negotiations.
Despite escalating tensions, Ethiopians remain optimistic about the dam's potential to elevate their regional standing and fuel economic development. The road ahead reveals a challenging yet pivotal juncture in the complex dynamics of Nile River politics.
