by JOHN H. LIENHARD V and KENNETH M. STRZEPEKSEPT
September 30, 2015
CAMBRIDGE, Mass. — On the Blue Nile in Ethiopia, construction is underway on a public works project of gigantic physical proportions and exquisite political delicacy. The Grand Ethiopian Renaissance Dam, now about halfway finished, amounts to a test: With water becoming precious enough to be the stuff of war, can nations find ways to share it?
So far, so good. The project is moving toward completion, and a recent joint declaration of principles by the leaders of Egypt, Ethiopia and Sudan pledges cooperation and no “significant” downstream harm. That is critical, given that the dam will control nearly two-thirds of the water on which Egypt depends. But for the cooperation to be meaningful, these three countries will need serious technical analysis. Poor assessment of such matters as the variability of annual rainfall or minimum flows required to maintain downstream water quality could undermine a decent agreement, leading to conflict of unpredictable intensity.
That’s because the flow of the Nile is climatic roulette. It experiences periods of plentiful water and periods of extended drought, and it always has: Remember the story (in both the Bible and the Quran) of seven years of plenty, and then seven lean years? But now the stakes are much higher: Egypt’s population is 90 million, and growing. That country’s Aswan High Dam, downstream from the Ethiopian dam, helps to moderate these fluctuations, but a second large dam and its reservoir higher upriver are going to complicate things.
Egypt now receives virtually all its water from the Nile — about 60 billion cubic meters a year, slightly above the amount provided for in its treaty agreement with Sudan. That amounts to the withdrawal of 700 cubic meters per capita per year. Compare that with California, which annually withdraws about 1,400 cubic meters per capita from multiple sources, including 30 percent of the Colorado River’s annual flow, and you understand just how scarce and precious the Nile’s water is to Egypt’s welfare.
California depends heavily on Lake Powell and Lake Mead, the reservoirs behind dams on the Colorado River, which together store slightly more than three years’ worth of that river’s total flow. The new dam in Ethiopia will have an even larger storage capacity than that of Powell and Mead combined, but still amounts to just 1.5 years of the flow of the Blue Nile alone. Adding in the very large reservoir behind Egypt’s Aswan High Dam gives a storage of about 1.75 years of the total flow of the Nile. It’s not a wide margin of safety for a long drought — as Californians will attest.
The monsoon rains in Ethiopia that will feed the new dam come mainly during just three months, so by storing that water, the new dam will moderate and smooth out the flow of the Blue Nile, the 900-mile-long headstream of the Nile itself. It will also generate huge amounts of electricity, the sale of which could finance much-needed development in Ethiopia — except that transmission lines to export the power are not yet being built.
Just as California has used stored water to become an agricultural powerhouse, Sudan will benefit by using the more stable flow of water from the new dam to raise its agricultural productivity. This will allow Sudan, which sits between Ethiopia and Egypt, to finally employ its full treaty allotment of river water, which in turn will reduce what is available to Egypt.
It’s clear that a cooperative agreement among Ethiopia, Sudan and Egypt is needed to avoid conflict and downstream harm. This includes agreement on what amounts to “significant” harm, given that, in the past, Egypt has been willing to go to war to protect its water.
All three countries stand to benefit if they work together. The dam’s huge storage capacity could help both Sudan and Egypt during drought years. And if Egypt were to agree to buy the power that the new dam will generate (and to build the transmission lines to connect to it, perhaps with international help), then Ethiopia will benefit economically from stored water that has to flow downstream eventually.
Here is where the technical issues will be critical. Last November, the Abdul Latif Jameel World Water and Food Security Lab at M.I.T. convened experts on Nile Basin water resources. They pointed out that management of a river system with multiple dams required sophisticated joint management with a shared knowledge base and scientific modeling framework. The hard negotiations ahead to achieve detailed agreements on such things as reservoir operation policy, power trading, dam safety and irrigation practices will require that foreign policy and water experts from each of the three countries have a shared understanding of the technical issues and a willingness to compromise.
In May 2015, the three countries engaged technical consultants to assist with these problems, but that arrangement has since collapsed over disagreements about project management. It behooves the international community to help, through support of regional efforts like the Nile Basin Initiative, to build scientific and engineering coordination and knowledge among the three countries, provide impartial expertise, set up a management system and perhaps offer a process to resolve disputes.
The world needs to get good at sharing water, and right away. The alternative is frequent regional conflicts of unknowable proportions.
John H. Lienhard V is a professor at M.I.T. and director of the Abdul Latif Jameel World Water and Food Security Lab. Kenneth M. Strzepek is a research scientist at the M.I.T. Joint Program on the Science and Policy of Global Change.
Source: ‘The New York Times’, September 28, 2015