Irrigation canals of Gezira Scheme from space, 1997.
The Gezira Scheme (Arabic: مشروع الجزيرة) is one of the largest irrigation projects in the world. It is centered on the Sudanesestate of Al Jazirah, just southeast of the confluence of the Blue and White Nile rivers at the city of Khartoum. The Gezira Scheme was begun by the British and distributes water from the Blue Nile through canals and ditches to tenant farms lying between the Blue and White Nile rivers.
The Gezira (which means "island") is particularly suited to irrigation because the soil slopes away from the Blue Nile and water therefore naturally runs through the irrigation canals by gravity. The soil has a high clay content which keeps down losses from seepage. The first plan was to grow wheat but this was abandoned when it was discovered that Egyptian-type long staple cotton could be grown. Cotton was first grown in the area in 1904 and, after many experiments with irrigation, 9 square miles (24 km2) was put under cultivation in 1914. After the lowest Nile flood for 200 years, the Sennar Dam was constructed on the Blue Nile to provide a reservoir of water. This dam was completed in 1925 and is about 2 miles (3.2 km) long. The Gezira Scheme was initially financed by the Sudan Plantations Syndicate in London and later the British government guaranteed capital to develop it. The Gezira Board took over from private enterprise in 1950.
Farmers cooperate with the Sudanese government and the Gezira Board. This network of canals and ditches is 2,700 miles (4,300 km) long, and with the completion in the early 1960s of the Manaqil Extension on the western side of the Gezira Scheme, the irrigated area now covers 3,400 square miles (8,800 km2), about half the country's total land under irrigation. The main crop grown in this region is still cotton.