While Mubarak was in power, he used Egypt's political and military weight in the region to resist any change to the country's dominance of the Nile's waters that dates to the British colonial era.
But the Supreme Council of the Armed Forces, which forms the interim government since Mubarak was forced out by a popular pro-democracy uprising Feb.11, is displaying signs of being more cooperative in this long-running dispute.
This probably has a lot to do with the plethora of pressing problems Egypt faces as its moves through the uncertain transition toward political and economic reforms.
Apart from anything else, the independence of South Sudan July 9, splitting Sudan, Egypt's ally in the Nile dispute, in two, undercut Cairo's intransigence.
South Sudan, which has voting rights as the 10th riparian state in the Nile Basin, says it too wants to build hydroelectric dams on a tributary of the White Nile to give the impoverished, infant state an economic boost.
As early as September, SCAF agreed to set up a joint technical team with Ethiopia, the most vociferous of the upstream states demanding a more equitable share of the Nile's water, to review the impact of a $4.8 billion Grand Renaissance hydroelectric dam Addis Ababa declared it planned to build.
Experts from Sudan, another Nile state and Egypt's neighbor, will also take part in the team's operation.
Prime Minister Meles Zenawi, Ethiopia's strongman and Mubarak's fiercest opponent on the Nile issue, moved swiftly after the Egyptian dictator was toppled.
In May, Zenawi agreed to delay ratification of a 2010 agreement signed by six of the nine upstream states that stripped Cairo of the right under a 1929 British-orchestrated treaty to 75 percent of the Nile's flow, until a new Egyptian government was elected.
Egypt insisted on maintaining the 55.5 billion cubic meters it takes annually from the Nile, at 4,163 miles the world's longest river.
That's more than half the total annual flow of 84 billion cubic meters. Egyptian authorities say the country will need 86.2 billion cubic meters by 2017, a volume it cannot meet given its current resources.
The Nile, which rises in Lake Victoria in East Africa, is literally Egypt's lifeline. Most of its 81 million people live along its banks. Without the Nile, the ancient civilization that built the pyramids would never have emerged.
Zenawi infuriated Mubarak by building five big dams on the Nile over the last decade, defying Cairo's right under the 1929 treaty to have a veto over all upstream dam projects.
Apart from the Grand Renaissance Dam, which will be the largest in Africa, Ethiopia says it plans to build two other dams on the Nile as part of a program to boost its electricity production to 20,000 megawatts over the next decade.
President Yoweri Museveni of Uganda, another of the key upstream states lined up against Cairo, also wants to build a series of dams to boost his country's generating power from 300 MW to 3,800 MW over the next five years.
"We also have plans to generate 17,000 MW by 2025," Museveni said.
In September, Zenawi met Egypt's caretaker Prime Minister Essam Sharaf in Cairo in a further effort to reduce tension and negotiate a new agreement.
"We can make the issue of the Grand Renaissance Dam something useful," Sharaf said, indicating that progress was now possible.
"This dam, in conjunction with the other dams, can be a path for development and construction between Ethiopia, Sudan and Egypt."
There are other issues involved in the Nile dispute. But the most threatening is the scramble by non-African states such as Saudi Arabia, China, India and South Korea to buy or long-lease vast tracts of arable land in Africa to produce wheat, rice and corn for export to those countries.
These land grabs cut the food supply in famine-prone African countries and the export of grain to nations unable to grow enough for themselves -- like Egypt.