In most developing countries wastewater treatment systems have very low coverage or function poorly, resulting in large-scale water pollution and the use of poor-quality water for crop irrigation, especially in the vicinity of urban centres. This can pose significant risks to public health, particularly where crops are eaten raw.

This paper summarizes research on the Krishna River Basin in southern India, including physical and agricultural geography, remote sensing, hydrology, water management, and environmental
issues. Discharge from the Krishna into the ocean decreased rapidly from 1960-2003 due to irrigation expansion. Annual runoff to the ocean fell from a pre-irrigation average of 56 cubic
kilometers (km3)(1901-1960) to 13 km3 (1994-2003), despite no significant change in rainfall. By the late 1990s, the cumulative reservoir capacity in the basin approximated the annual runoff