Ord River, in Western Australia, rises near Halls Creek and flows northward for 300 miles (480 kilometers) into Cambridge Gulf, near Wyndham. Together with its tributaries, it drains an area upstream of the Ord River Dam of about 18,000 square miles (47,000 square kilometers). The Ord is the source of water for a major irrigation project designed to provide water for 185,000 acres (75,000 hectares) of land devoted to tropical and subtropical crops. About 35,000 acres (14,000 hectares) have already been developed. The irrigation scheme includes Kununurra Diversion Dam and the Ord River Dam.
The diversion dam, about 60 miles (100 kilometers) from the mouth of the Ord, holds about 77,800 acre-feet (96 million cubic meters) of water. The Ord River Dam, about 30 miles (48 kilometers) farther upstream from the diversion dam, holds about 4.6 million acre-feet (5.7 billion cubic meters) of water, nine times the volume of water in Sydney Harbour. Water from the Ord River Dam is released as required to the diversion dam, which feeds the irrigation channels. Major crops raised in the area include melons, sugar, mangoes, seeds, pumpkins, and bananas.
The Kununurra Diversion Dam was completed in 1968. The Ord River Dam was begun in 1969 and completed in 1972. At that time, planners estimated that the Ord Valley would eventually support 20,000 people. But in the 1970’s, farmers in the area encountered a number of major problems, including pests that attacked cotton and a slump in the world demand for beef and agricultural produce.