Harness for the Nile

The River Nile, which has controlled the lives of millions of men in the last 7,000 years, may soon be completely controlled by man. After years of bickering, the British and Egyptian governments have agreed to start a system of dams on the upper tributaries which will eventually turn the unpredictable Nile into an obedient, dependable slave.

The trouble with the Nile has always been its irregularity. Most of the year it flows sluggishly far below its banks. But between July and October, a great gush of muddy water floods the narrow, fertile valley. For the ancient Egyptians, who did not demand too much of their sacred river, the flood was fine. They built mud dikes around the fields, and caught the flood water in shallow basins. The silt settled to the bottom, keeping the soil fertile, millennium after millennium. When the water. was gone, the peasants planted their crops, often without plowing or other preparation, in the wet soil.

This system, essentially unchanged, is still used in much of Egypt. It is no good for growing cotton and other long-season crops, so it has been supplanted in the lower valley by dams and canals that make year-round irrigation possible. For the modern system, the irregularity of the Nile is a serious matter. During the annual flood, much water goes out to sea unused; during the rest of the year, there is not enough water. A great deal more acreage could be devoted to the valuable long-season crops if the Nile could be forced to flow steadily all the year round.

Natural Reservoirs. The object of the new dams on the headwaters is to even out the flow, holding water in reservoirs during the flood season, and letting it out when needed. Luckily for Egypt, the reservoirs are already half built. On the main tributaries, the Blue and White Niles, there are big lakes that need only dams at their outlets to turn them into ideal storage basins.

Most of the Nile's annual flood comes roaring down the Blue Nile and the neighboring Atbara when moist seasonal winds blowing across central Africa hit the high mountains of Ethiopia. A dam at the outlet of Lake Tana on the Blue Nile's headwaters will deepen the lake by about 13 feet, and allow it to hold in reserve for the dry season some 1,400 billion gallons of water. With necessary roads, power plants, etc. in wild Ethiopia, this dam is expected to cost $28 million.

The White Nile is a tougher engineering problem. Its two huge lakes, Victoria and Albert, will be made into reservoirs with enough storage capacity to give complete control of the tributary. A lesser dam must be built to control the water in swampy Lake Kioga.

Thirsty Sudd. Below Lake Albert lies the Sudd, a vast swamp choked with papyrus and other tall grasses. The White Nile seeps slowly through this tangle, and loses nearly half its water in the process. Engineers plan to cut a canal 186 miles long, to bypass the water-stealing Sudd.

The first dam to be built on the White Nile will be at Owen Falls, at the outlet of Lake Victoria. Another will make a reservoir out of Lake Albert. When the whole system is in operation, the water of the White Nile can be held back while the Blue Nile is flowing. The system is expected to smooth out the flow of the lower Nile through Egypt and increase the cultivated area by 1,500,000 acres.

It will do more, Egyptians hope. Some seasons there is not enough rain in Ethiopia to send a proper flood down the Blue Nile. Then in the parched land, the crops dry up. In the long history of Egypt this disaster has often happened for several years in succession, causing serious famines. It probably happened during 'the "seven lean years" which allowed Joseph to speculate in grain and enslave the Egyptians for Pharaoh (Genesis: 41).

The Egyptians hope that the new system of dams will eliminate this danger, by providing "century storage" of Nile water. The stored reserves should keep the Nile flowing through the worst succession of dry years.

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