Sheliff(both: shālēf`), river, c.420 mi (680 km) long, N Algeria. It rises in the Amour Mts. of the Saharan Atlas and empties into the Mediterranean Sea near Mostaganem. The Chéliff, the longest river in Algeria, is not navigable, but its waters are used for irrigation and hydroelectric power.
(Oued Chéliff), the largest river in Algeria, North Africa. The Chéliff is 700 km long, as measured from the source of its farthest tributary, the Oued Touil (Oued Sebgag), and drains an area of approximately 35,000 sq km. It originates on the northern slopes of the Djebel Amour of the Saharan Atlas. Crossing a rock desert, the upper course of the Chéliff carries little water and dries up in places in the summer. Farther downstream, the river turns west and flows through a broad, well-developed alluvial valley before emptying into the Mediterranean Sea. Water levels are high in the winter, with the occurrence of sometimes disastrous freshets and a flow rate that can exceed 4,000–5,000 cu m per sec. The high water levels of winter are followed by a period of very low water during which the flow rate may drop to several hundred or even tens of cubic meters per second. The Ghrib Reservoir and a hydroelectric power plant are on the Chéliff, whose waters are used extensively for irrigation.