India Deploys Helicopter Surveys to Map Hidden Aquifers Across Water-Stressed Regions

India's Central Ground Water Board is using heliborne Time Domain Electromagnetic surveys to map aquifer depth, thickness, quality, and paleochannel networks at a speed and resolution unattainable by conventional methods. The technology has already covered more than 97,000 square kilometres across Rajasthan, Gujarat, Haryana, and the Ganga plains.

Heliborne TDEM systems emit controlled electromagnetic pulses into the ground from a sensor ring suspended beneath a helicopter, reconstructing three-dimensional subsurface images without drilling. Surveys covering thousands of square kilometres per week replace fieldwork that could take months to characterise a few square kilometres. In the Ganga-Yamuna Doab, surveys between 2016 and 2021 mapped paleochannels — ancient buried river courses — containing large reserves of fresh groundwater that satellite or surface surveys had not detected.

India extracts approximately 240 billion cubic metres of groundwater annually, making it the world's largest groundwater consumer. Around 60 per cent of all irrigation, 85 per cent of rural drinking water, and more than 50 per cent of urban water demand is met from groundwater. In arid western India and over-exploited plains states, failed boreholes and dry wells directly threaten livelihoods. The CGWB surveys in Rajasthan, Gujarat, and Haryana covered 92 administrative blocks, identifying fresh-saline boundaries, desaturated zones, and optimal recharge sites for check dams and recharge shafts.

Processed findings from the surveys were interpreted down to the gram panchayat level along each flight line, providing district authorities with block-level groundwater reports and practical drilling and recharge recommendations. As monsoon patterns grow more erratic under climate change, the ability to locate and bank groundwater before rainfall arrives represents a strategic shift from reactive crisis management to proactive resource stewardship — a transition the authors argue India urgently needs.

Key figure — 97,165 square kilometres surveyed in Rajasthan, Gujarat and Haryana