A new study published in Hydrological Processes has revealed that the Ganga river’s main source of water isn’t glaciers — but groundwater.

Conducted by Professor Abhayanand Singh Maurya and his team from IIT Roorkee, the study shows that groundwater aquifers contribute over 120% more volume to the Ganga as it flows through the plains, compared to its origin in the Himalayas. While glaciers and snowmelt feed the river upstream, most of the water in the 1,200 km stretch through the Indo-Gangetic plains comes from groundwater.

Experts say this finding changes how we must view river conservation. Over-extraction of groundwater, pollution, and evaporation are now posing serious threats to the river’s natural flow.

Environmentalists stress that saving the Ganga means saving its groundwater, not just cleaning its surface. Programs like Namami Gange need to focus on recharging aquifers, restoring tributaries, and reducing diversion from dams.

The National Green Tribunal has already sought a response from the environment ministry — proving the study’s impact is echoing beyond academia.