Conjunctive-use management
Different approaches to groundwater governance are needed for‘groundwater-only’ irrigation and ‘conjunctive-use’ irrigation. GWP (2012)12 explores the technical options. Here, the focus is on approaches to groundwater governance to improve conjunctive management of surface water, groundwater, and salinity.
The Indus Basin Irrigation System (IBIS), encompassing Pakistan Punjab and Sind, and the Indian states of Punjab, Haryana, and Rajasthan, represent a peculiar class of groundwater depletion problems in the midst of canal command areas. From 1850 these dry areas began supporting vibrant irrigated agriculture as vast areas were brought under canal irrigation. In recent decades, massive expansion in private tubewell irrigation has created large and growing pockets of groundwater depletion while other areas face water logging and secondary salinisation. One instrument of sustainable groundwater management lies in curtailing the use of surface-water supplies in water-logged areas and augmenting it in groundwater-depleted areas. A major limitation, however, is the salinity in the water and soil (Evans and Evans, 2011). In many saline areas in the IBIS command, farmers demand surface water primarily for blending with saline groundwater (Box 5).