Assessing the necessity of water transfer using SWAT modelling

Assessment of water resources potential through hydrological modelling is an essential work in managing hydrological extremes. This study focuses on assessing net water availability in the Left Bank Catchments of the Cauvery River Basin, Tamil Nadu, using the Soil Water Assessment Tool and Water Budgeting Method for the period from 2001 to 2020. The estimated average runoff volume obtained post calibration of the model is 2704 Mm 3, with average total water demand 9620 Mm 3 per year, in which 74 % (about 2.6 times of average runoff) belongs to the irrigation water demand. Hence, a large quantity of water is required to minimize the deficit, and that can be achieved only by diverting flood water from the Cauvery River (at the downstream side of Mettur dam) through a canal combined with modern irrigation practices. Since the flood release alone is said to be diverted, it will not affect the regular flow in the river, and it will not disturb the current water transfer practices, and the food production will become sustainable in this area.