Groundwater comprises 97 percent of theworlds readily accessible freshwater and provides the rural,urban, industrial and irrigation water supply needs of 2billion people around the world. As the more easily accessedsurface water resources are already being used, pressure ongroundwater is growing. In the last few decades, thispressure has been evident through rapidly increasing pumpingof groundwater, accelerated by the availability of cheapdrilling and pumping technologies and, in some countries,energy subsidies that distort decisions about exploitinggroundwater. This accelerated growth in groundwaterexploitation unplanned, unmanaged, and largely invisible hasbeen dubbed by prominent hydro geologists the silentrevolution. It is a paradox that such a vast and highlyvaluable resource which is likely to become even moreimportant as climate change increasingly affects surfacewater sources has been so neglected by governments and thedevelopment community at a time when interest and supportfor the water sector as a whole is at an all-time high. Thiscase study is a background paper for the World Bank economicand sector analysis (ESW) entitled too big to fail: theparadox of groundwater governance that aims to understandand address the paradox at the heart of the groundwatergovernance challenge in order to elevate the need forinvesting in and promoting proactive reforms toward itsmanagement. The project examines the impediments to bettergovernance of groundwater, and explores opportunities forusing groundwater to help developing countries adapt toclimate change. Its recommendations will guide the Bank inits investments on groundwater and provide the Bank'scontributions to the Global Environment Facility (GEF)funded global project groundwater governance: a frameworkfor country action. The case study focused on the national,state and local levels. At the national and state levels, itanalyzed the policy, legal, and institutional arrangementsto identify the demand and supply management and incentivestructures that have been established for groundwatermanagement. At the local level, it assessed the operations,successes, and constraints facing local institutions in thegovernance of a number of aquifers within peninsula India,on the coast and on the plain of the Ganges river valley.