Nature of Aquifer in Parts of Granitic Terrain in Mahabubnagar District, Andhra Pradesh

Hydrogeological studies in the granitic terrain in parts of Mahabubnagar district, Andhra Pradesh, indicate a fairly thick and well distributed weathered zone, linear zones of fractures and deep water levels. The higher yields of some of the bore wells are due to the presence of N-S or E-W fractures. Pumping tests on 23 dug wells and three bore wells drilled within the weathered zone indicate a lower transmissivity values when compared with the pumping tests conducted on four bore wells which encountered fractured zones.

The gross ground water extraction per unit area hardly varies in sampled areas that form sman second order basins, irrespective of well density or type of wells. The number of dug wells drying-up in parts of the area is proportional to the success of the bore wells in the area. It suggests that new and deeper wells are only replacing the older, shallower dug wells and that the deeper fractured zone aquifer and shallower weathered zone aquifer are well connected.

This study also shows that the limiting factor for ground water development is not the nature of the aquifer but the quantum of recharge to it. Hence, artificial recharge structures must be planned to improve availability of ground water in the area.