Abstract:
Irrigation tanks are one of the oldest and most important common property water resources in the resource poor regions especially in South India and Sri Lanka. Tank irrigation accounts for more than 30% of total irrigated area in South Indian states. In Tamil Nadu alone there are 39200 tanks of varying sizes and types. Variation in rainfall quantity (total amount) and quality (intensity) significantly affects tank water supplies. This resulted in declining performance of the tanks. The objective of this study was to calculate the stabilization value of groundwater in the tank irrigation systems. Cross sectional data in the year 2006/2007 on water storage in randomly selected twelve tanks in these two districts, of which ten tanks in Sivagangai district and two tanks in Madurai district of Tamil Nadu were taken for this study. These two districts were selected as they are identical in using tank water supply with ground water. Keeping the importance of groundwater in the tank system, the stabilization value was worked out using the stabilization value model, which was found to be Rs. 291,123. The results confirm that the positive and higher value of groundwater in the tank system justify the need for investment in wells in the tank command area. Thus, keeping the balance of tank water and groundwater, the performance of the tanks could be stabilized.
