Sudan is aggressively seeking to tap its abundant Nile waters with new dam projects as the oil-rich south's independence looms, but experts warn of the social and environmental costs, and the bearing on the Nile water sharing dispute.
Khartoum sits on the confluence of the Blue and White Niles.
The cash-strapped government has good reasons for wanting to exploit its "blue gold," a valuable resource that will help to offset the imminent loss of revenues from southern oil -- some 36 percent of its income -- when south Sudan proclaims independence on July 9.
"Sudan is clearly gearing up in terms of agriculture, because of the oil gap that comes with the separation of the south. To the extent that it can do more in the way of dams, that is its economic security," said a Sudan-based environmentalist, requesting anonymity.
Last week, during a ministerial visit, the engineer responsible for heightening the vast Roseires dam, on the Blue Nile, said the $400 million project, which is due for completion in June 2012, would create three million feddans (1.3 million hectares) of farmland.
It will also more than double the amount of water the reservoir can store -- to 7.4 billion cubic metres -- and raise its 280 megawatts of power generation capacity by 50 percent.
The Atbara and Seteet dams being built in Kassala state, meanwhile, will add another one million feddans of new farmland and have a combined generation capacity of 320 megawatts when they are completed in September 2015, at a cost $840 million, according to their chief engineer.
The Gulf-funded and Chinese-built dam projects that the Sudanese government has embarked on dwarf other public development programmes.
"Sudan's ambitious dam strategy has been the single biggest source of discretionary spending in the last few years and represents a key development priority," said Harry Verhoeven, an expert on water and agriculture in Sudan, in a report published this month by the Chatham House think tank.
"The Merowe Dam alone (completed in 2009 at a cost of more than $2 billion) took up almost 40 percent of total public investment in national development projects between 2005 and 2008."
But there are doubts about the cost effectiveness of such massive schemes, and major concerns about the displacement of tens of thousands families, as well as the environmental implications of building the dams at relatively low altitude.
The raising of Roseires is expected to see the resettlement of 22,000 families, which the Minister of Electricity and Dams, Osama Abdullah, said would prevent them from being affected by the seasonal flooding of the Nile.
But others say the change will be a traumatic experience for those forced to move, as with the more than 40,000 people who were ordered to leave their homes to make way for the Merowe dam and its vast reservoir three years ago.
In addition, as Verhoeven argues, if such projects had been built on Ethiopia's stretch of the Blue Nile, at higher altitude, the evaporation rates would have been seven times lower than in Sudan and caused less displacement.
But Sudan appears in no mood to question its projects, and is negotiating with a another Chinese contractor to build the Kajbar dam further downstream, on the third cataract of the Nile, at an estimated cost of $700 million.
Some experts point to another factor motivating Sudan's dam building strategy, namely concerns about its future allocation of Nile waters.
Upstream countries that share the Nile River basin have demanded the revision of colonial-era agreements that allot more than 90 percent of the river's water to Egypt and Sudan and allow Cairo to veto upstream projects.
The revised agreement has been signed by Ethiopia, Kenya, Rwanda, Tanzania, Uganda and Burundi and seeks to allow irrigation and hydroelectric projects to go ahead without downstream consent.
"The sticking point in renegotiating the Nile basin treaty is the allocation of water quantities," said the environmentalist who asked not to be named.
"Unlike Egypt, Sudan is not using all of its existing allocation. That is partly why Sudan is so keen to build new dams. It gives it a stronger position when they're negotiating the new treaty," he added.
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