Chasing the water table: The impact of groundwater depletion on rural drinking water supply in peninsular India

Groundwater overexploitation has been cited as one of the biggest threats to rural drinking water in India, but there is very little quantitative evidence. In this paper, we aim to understand (1) the extent of actual groundwater depletion and its impact on rural drinking water supply systems, (2) the primary driver of groundwater depletion and (3) the additional financial burden in finding new sources for water supply and increased O&M costs.We rely on temporal data from two Gram Panchayats (local administrative unit) near Bengaluru, in south India. Our study results confirm that groundwater depletion, in this hard rock aquifer region, is a severe problem, driven largely by agricultural water abstraction. Rural drinking water supply systems have had to catch up continuously with the falling water table, abandoning non-functional wells and drilling new borewells to replace them. This has resulted in a major financial burden to the Gram Panchayats both in terms of increased capital and O&M costs. Increased pumping costs associated with declining groundwater levels impose a major burden on these Gram Panchayats, which are severely in “electricity debt”. Hitherto, state and central government grants have paid for rural well installation in India, but these schemes are time bound, posing a threat to future drinking water security.