Sutlej River, a major river of the Indus system in southern Asia. It is about 850 miles (1,370 km) long. From its source in the Himalayas in Tibet the Sutlej flows through the Punjab region of northern India and Pakistan and merges with the Chenab River near the Pakistani city of Alipur. The combined rivers, called the Panjnad, continue on for about 50 miles (80 km) to join the Indus. The Beas River in India is the Sutlej's principal tributary. Water rights to the Sutlej were disputed by India and Pakistan until the Indus Waters Treaty in 1960 allocated them to India. Bhakra Dam, completed on the river in 1963, provides abundant hydroelectric power and water to irrigate some 5,000,000 acres (2,000,000 hectares) of land.