IWRA Proceedings

AbstractSince the 1850s, progressive agricultural and water development in the Krishna basin in south India has led to a rising over-commitment of water resources. This over-commitment and signs of basin closure are apparent during dry periods: surface water resources are almost entirely committed to human consumptive uses; increasing groundwater abstraction negatively affects the surface water balance by decreasing base flows; and the discharge to the ocean continues to decrease. The observed runoff to the ocean fell from a pre-irrigation development average of 57 km3 a year in 1901-1960, to less than 21 km3/yr in 1990-2000 and even more strikingly to 0.75 km3 in 2001-2004 during an extended period of low rainfall. Based on basin-wide historical water accounting, this paper quantitatively describes the process of closure of the Krishna basin over the last fifty years. In the early 2000s, and without accounting for any environmental flows, total committed volumes accounted for more than 99.4% of the renewable blue water of the basin. Based on this quantitative assessment, the paper attempts to unpack the forces that drove the overbuilding and closure of the Krishna basin. It argues that is not only the availability of the physical resource that is crucial in explaining water use dynamics but that current social, economic and political forces have contributed greatly to the mostly ad-hoc reconfiguration of the Krishna basin waterscape. Capturing the process of basin closure requires understanding of the political dimension of access to water and the scope for change. Despite rising inter-sectoral and inter-regional tension and reduced investments in rural development, the three states that share the Krishna waters continue to promote their agriculture and irrigation sectors but when a river basin closes, adjustments and management decisions are tantamount to a spatial re-distribution of water among sectors and regions. This development path can no longer be sustained without impinging on existing water use; leading to further water shortage downstream; severely degrading the resource base; further damaging the environment and; creating conflicts. To overcome the difficulties that such adaptive mechanisms may create, there is a clear need for a basin-wide strategy for water management and development that would start with the definition and the implementation of water allocation mechanisms to ensure a balance between equity, sustainability and efficient uses of scarce water resources for both human benefit and environment preservation.