Stabilisation value of groundwater in tank irrigation systems

In Andhra Pradesh, Karnataka, and Tamil Nadu States in India, tank irrigation accounts for more than one-third of irrigated area. Aside from irrigation, the tank also enriches the water table through percolation, and extremely useful in maintaining the water table to ensure sustained growth of flora and fauna. However, the poor performance of the tanks resulted in heavy dependence on groundwater supplementation. Groundwater stocks are relatively stable caused by wells get the recharge both from tanks and from the irrigated rice fields. The concept of "stabilization value of groundwater" introduced by Tsur, has gained importance in tank systems of Tamil Nadu. The study presented by Ranganathan and Palanisami regarding the stabilization value of groundwater in tank systems, had indicated several tank improvement options including channel lining, sluice management, sluice rotation, and providing additional wells. These options could provide about 20% saving in tank water, meaning 20% less demand for groundwater.