Indus

The Indus river basin on the Indian subcontinent stretches over 1,165,000 sq km. Its riparian states are Afghanistan, the Tibetan regions of China, India and Pakistan. It drains into the Arabian Sea at Karachi, southern Pakistan, after traversing the whole of the Indus plains in Jammu and Kashmir, India and Pakistan (mainly the provinces of Punjab and Sindh) and uniting the flows of its seven main tributaries. Today, tributaries can be distinguished joining the Indus’ main branch from the left (south-eastern) and from the right (north-western) sidea fact that has inspired the sharing agreement between India and Pakistan. Water and its availability have played a crucial role for the civilizations that

settled along the banks of the river over several millennia because of the dry conditions prevalent in most of the mid-and downstream areas of the basin. Agriculture traditionally constitutes the main water-consuming sector, and hydropower is a very important non-consumptive use. In the ancient kingdoms of the Indian subcontinent, control over water

resources and their distribution was already a key factor in realizing agricultural potential. Simple damming and diversion structures, small storage tanks as well as distribution canals, have existed there since 300 BC. The British East India Company, as the operational branch for colonial production in the British Empire since the mid-18th century, enlarged the pre-existing systems in the eastern part of the subcontinent (what is today Indian territory) with modern-type barrages and irrigation canals. In the 1840s, the British Government took control of the structures and their operation; this development coincided with the conquering and annexation of Punjab and Sindh, making possible the hydrologic control of the population and the new settlers. Before this period, the banks of the Indus were irrigated only through inundation of narrow strips along the banks during the annual peak flows of the Indus. From the 1850s, irrigation development was systematically utilized to fight the frequent famines by spreading the waters over as much area as possible to provide a so-called deficit irrigation. Under this water control regime, maximum productivity was not the objective, rather the avoidance of social unrest and, at a later stage, the enforced colonization of the territory and settlement of veterans. From the late 19th century until the independence of British India and the subsequent partition into India and Pakistan, all rivers were tapped for irrigation; major barrages as intakes for perennial-flow irrigation canals improved the thus-far prevalent inundation canal system and made possible the cultivation of crops during two seasons.