Study identifies how poor farmers replenish groundwater for wealthier neighbors

Researchers at the Indo-French Cell for Water Sciences and the Indian Institute of Science developed a new framework to track how different social groups of farmers affect groundwater levels in India.

The team published their findings in the Journal of Hydrology, arguing that traditional water accounting often ignores who helps replenish the water and who depletes it.

The researchers created a tool called blue water potential to measure whether a specific farming method adds to or takes away from an aquifer. They found that wealthy farmers in the Rayalaseema region of Andhra Pradesh primarily grow fruit orchards like pomegranate and grapes. These orchards consume 1,000 to 1,200 mm more water per year than they return to the ground.

In contrast, poorer farmers who grow rain-fed peanuts and maintain grasslands actually contribute 200 to 300 mm of water back into the aquifer annually. The study shows that a small minority of wealthy farmers uses most of the groundwater, while the majority of poorer farmers and pastoralists provide the recharge that sustains the system. Charlotte Hemingway, a researcher at the Indo-French Cell for Water Sciences, warned that small increases in fruit tree cultivation could cause overexploitation of the water supply.

This research comes as the Andhra Pradesh government plans a 1 lakh-crore rupee project to expand the region's horticultural area to 1,441,000 hectares. The researchers released open-source software to help others calculate water potential for different regions. M Sekhar of the Indian Institute of Science stated that officials need a robust assessment to see how much water must be imported through canals to maintain a stable water balance against climate risks.