This paper analyzes the institutions and markets that govern groundwater allocation in the sugarcane belt of Uttar Pradesh, India, using primary plot-level data from a village which shares the typical features of this region. Electricity powers tubewell pumps, and its erratic supply translates into randomness in irrigation volumes. The paper finds that plots are water-rationed, owing to inadequate supply of power. A simple model shows that a combination of such rationing and the village-level mechanism of water sales can lead to great misallocation of water across plots, and result in large crop losses for plots that irrigate using purchased water.