Shrinking groundwater in India’s population epicentre

The Upper Ganga Basin (UGB) in Uttar Pradesh, one of the most populous regions in India, has experienced a continuous decline in groundwater levels over recent decades. On the basis of in situ observations, simulations show that the western part of Uttar Pradesh and several districts of southern Uttarakhand (covering an area of ~ 150,229 km 2 ) has lost an estimated 62 km 3 of groundwater during 2005–2023, which is five times the storage capacity of India’s largest reservoir. GRACE satellite-derived estimates of groundwater storage change also corroborate with the estimated rate of groundwater decline featuring a correlation coefficient of 0.8 with in situ data. The present study reveals that frequent droughts in the area have reduced natural recharge from rainfall and increased groundwater abstraction. Groundwater abstraction from confined aquifers contributes towards ~ 42% of the total groundwater abstraction, which has increased over time as the number of deep tube wells has surged exponentially. To mitigate such a predicament, urgent action is required for sustainable management of groundwater, which can be achieved by changing agricultural practices (such as crop rotation), rejuvenating surface water bodies, developing managed aquifer recharge sites and adopting appropriate water use and management policies across local to state levels.