Drainage of Irrigated Lands

The necessity for providing drainage to remove water from irrigated lands seems anomalous. After paying the cost of supplying water to land, why should it be necessary to spend more money to take away a part of this water? The earliest records of activities of the human race in irrigation show that the drainage problem has always been important and lack of drainage has been a factor in great historical events. The Valley of the Tigris and Euphrates Rivers in old Mesopotamia, to a large extent, has returned to the desert. At one time nearly 10 000 000 acres of land “in ancient Chaldea" were, to quote the late Sir William Willcocks, “as fertile as a garden." The greater part of this region now consists of alkali flats and saline areas, barren of all but meager feed for flocks and herds of wandering tribesmen.