CAIRO // A hazy winter sun casts its glimmering light over the tranquil Nile as it flows through Cairo.
But while the waters may be untroubled in the Egyptian capital, they are at the centre of a nine-nation diplomatic dispute that involves next month's crucial referendum in southern Sudan.
That referendum, many expect, will result in a vote for the south's independence from the north. And an independent southern Sudan could tip the political balance in favour of a controversial water-sharing agreement supported by five Nile nations, but which Egypt bitterly opposes.
Cairo has described the water agreement, signed in May without its participation, as a threat to its national security because it would replace two colonial-era treaties that allocate most of the river's water to Egypt.
The agreement has been the source of an escalating dispute with Ethiopia, which argues for a more equitable distribution of water resources from the world's longest river. It has also been a factor in Egypt's quiet opposition to an independent southern Sudan, according to US diplomatic cables published by the whistleblowing website WikiLeaks.
Egypt's foreign minister, Ahmed Abul Gheit, met ministers from the Democratic Republic of Congo this month to discuss water-sharing issues, the latest in a two-week schedule of talks in which Egyptian officials visit Uganda and welcome the leaders of Tanzania and Burundi to Cairo.
Their efforts have already achieved at least one victory: Burundi's deputy president, Gervais Rovkiri, suggested his country would take Egypt's side in the water dispute after a meeting on December 6 with Ahmed Nazif, the Egyptian prime minister.
Egypt's immediate objective was to prevent the new water-sharing agreement from formally entering into force by ensuring that a sixth country in the Nile basin does not sign it, said Hani Raslan, the director of the Sudan and Nile basin studies programme at Al Ahram Centre for Political and Strategic Studies, a government-funded think tank in Cairo.
Of the nine countries in the Nile Basin Initiative, Ethiopia, Uganda, Rwanda, Tanzania and Kenya have signed the agreement; Egypt and Sudan oppose it; and Burundi and Congo remain undecided but are leaning towards Egypt's position.
"Egypt communicated with Burundi and convinced them not to sign, and Congo as well refused to sign," Mr Raslan said. "Egypt made all those efforts to convince the others to go back to negotiations and establish a solution to the controversial points."
However, an independent southern Sudan could swing the pendulum towards the new agreement, Egyptian officials told the US government in secret diplomatic cables published by WikiLeaks.
In an October 2009 cable published in the Egyptian press but not yet released by WikiLeaks, an unnamed foreign ministry official told US diplomats that an independent southern Sudan might end up as "a non-viable state that could threaten Egypt's access to the Nile waters".
Under a 1959 treaty signed with Sudan, Egypt is entitled to 66 per cent of the 84 billion cubic metres of Nile water that flow through the country each year. And a 1929 treaty with Britain, which at that time ruled most of eastern Africa, gives the Egyptian government final say on all dams and other large water projects in all Nile Basin countries.
Egyptian officials justify their disproportionate share of water by pointing out that their desert nation relies on the Nile for almost all its freshwater needs while upstream countries receive significant rainfall. Ethiopia and other upstream countries, however, describe the treaties as a vestige of colonialism that is holding back development of hydroelectric projects to power economic growth.
For now at least, the dispute is purely political, because the supply of water significantly exceeds the needs of all the Nile basin countries put together, Mr Raslan said.
"Practically speaking, it is impossible at the current time to establish any projects that may have an impact on the Egyptian share of water, and this may last for 20 or more years," he said.
But the Egyptian government projects water shortages as soon as 2017 even with its current share, while Ethiopia, the continent's second largest military power, raised tensions last month by accusing Egypt of supporting Ethiopian rebel groups. Egyptian officials dismissed the claims.
In remarks to local press, officials have shied away from talk of conflict and stressed the need to prolong negotiations as an alternative to the new water-sharing agreement.
On a visit to Uganda, one of the most outspoken proponents of the agreement, Egyptian officials sought the support of Ugandan officials by announcing a $1 billion (Dh3.67bn) partnership to build hydroelectric dams in the country through Taqa Arabia, a private Egyptian company.
A spokeswoman for Taqa Arabia said the agreement was "only a memorandum of understanding", and the company had not yet examined the feasibility of the project in detail.