There has been a declining trend in groundwater depths in India and subsidies on farm electricity contributes to over-extraction of groundwater raising concerns about its sustainability for irrigation. In this paper, we estimate the reduction in groundwater pumping under volumetric pricing of farm electricity for Punjab where farm electricity is free. We use parcel-level cost of cultivation data from Ministry of Agriculture for 2011-12 to 2013-14 to estimate the production function for paddy using instrumental variable approach. We find that the estimated marginal product of water function is relatively flat at the level of the average water application. The average marginal product of water is 32 kilograms for additional thousand cubic meters of water per hectare, which is very low. Simulations show that increasing the price of electricity from current level of zero to the true cost of electricity supply leads to sharp cutbacks of 59 percent in water extraction using electric pumps. However, the decline in average paddy yields is 11 percent. We show welfare gains in terms of reduction of the deadweight loss under volumetric pricing. Finally, we quantify average lump-sum subsidy that can be given to farmers as direct transfers to keep their surplus unchanged and we show that this can be financed using collections done by state electricity board from pricing electricity.