Studies on Impact of Water Management Practices on Sustainable Use of Water Resources under Tuntapur Tank in Raichur District of Karnataka

In the prevailing weather conditions of Karnataka, the tanks are not able to meet the increasing demand for irrigation due to the erratic nature of the monsoon rains, cultivation of paddy in non-localized areas and uncontrolled operation of the conveyance and application systems. A study was conducted in Tuntapur tank system to estimate the probable annual runoff entering the tank, the water demand from its command area and to prepare an optimized plan using water balancing technique while suggesting improvements. SCS curve number method was employed to predict the runoff generated in Tuntapur tank catchment. The study shows that water being used by the farmers in excess of the real requirement and that there was a good scope for improving the water management in the command area. Therefore alternative cropping plans were proposed by considering the different tank storage levels namely 100, 80, 60, 40 and 20 per cent of the maximum live storage of the tank naming them as plan-I, plan-II, plan-III, plan-IV and plan-V respectively. Water balancing technique was used to work out the proposed cropping pattern and area under different crops, based on the available water in the tank. The areas for paddy and groundnut were selected based on their suitability for the soils concerned and the topography. The logic behind reducing the paddy area is to reduce the water requirement and replacing that area by a light irrigated crop that have less consumptive use namely groundnut so that the total net income of the farmers can be increased by irrigating a larger area. The cost economics was worked out for existing practices and suggested plans.