The USA uses about 200 km3 of groundwater for irrigation, but to manage its economy it has to monitor and regulate only 400,000 pumping plants, each pumping 500,000 m3 of groundwater annually. Mexico is in a similar position with just 95,000 agricultural tubewells. However, India, which uses 230 km3, has to manage over 20 million small wells, each pumping an average of 11,500 m3 annually.