Decision Making Tool for Sustainable Water Sharing

This paper explores the possibility of using a calibrated rainfall-runoff model as a decision-making tool in sustainable water sharing. Designing institutional arrangements for runoff sharing process in the case of a sub-catchment spread across geopolitical boundary is challenging. For the water sharing arrangement to be sustainable, it must be founded on realistic runoff predictions. The climate uncertainties make the water sharing process more complex and complicated. This context warrants a decision-making tool for helping the water sharing policy makers and its managers in taking a decision. In this study, a decision-making tool for sharing the waters of Parambikulam sub-catchment in Southern Peninsular India is developed. RRL (Rainfall-Runoff Library), RAP (River Analysis Package) and SCL (Stochastic Climate Library) of eWater toolkit are used for developing this tool. In the decision making, it also incorporates the runoff change prediction portrayed in India’s second national communication to UNFCC. The existing institutional arrangement for water sharing of this sub-catchment is revisited in the light of findings of this study. Paper is concluded by explaining how it is useful in synthesizing a range of options on designing a new water sharing paradigm for this sub-catchment.