Many people still believe that India’s irrigation water mainly comes from canal irrigation systems. While this may have been true in the past, recent research shows that groundwater irrigation has overtaken surface-water irrigation as the main supplier of water for India’s crops. Groundwater now sustains almost 60% of the country’s irrigated area. Even more importantly, groundwater now contributes more to agricultural wealth creation than any other irrigation source (see Fig. 1). groundwater use has increased largely because it is a democratic resource,’ available to any farmer who has access to a pump. Accessibility has led to widespread exploitation of the resource, by farmers grateful for a reliable irrigation-water source. In turn, this has led to high levels of groundwater use being associated with high population density. But it is a myth that groundwater use is high only where supplies are high. Such findings are worrying, because the consequences of overexploitation of this precious and productive resource can be catastrophic. The research highlighted in this briefing identifies four stages of groundwater development. To avert potential disaster and maximize benefits of groundwater as a force for poverty reduction, new policies are needed at each of these four stages. It is crucial that policymakers intervene at these critical stages to manage both the supply and demand aspects of groundwater use. Urgent priorities are areas with low supplies of renewable groundwater but alarmingly high groundwater use, such as Tamil Nadu, Gujarat, Maharashtra, Andra Pradesh, Karnataka, Punjab and Haryana.