Overview

• IIT Roorkee researchers completed the first full-scale isotopic survey of the Ganga from its Himalayan origin to the delta and identified groundwater discharge as the primary summer source up to Patna.
• Subsurface inflows boost the river’s volume by nearly 120% between the Himalayan foothills and Patna.
• Over 58% of the Ganga’s summer discharge is lost to evaporation, revealing a major gap in its water budget.
• Two decades of in-situ monitoring and consistent shallow pump flows show central Ganga Plain aquifers remain stable and resilient.
• The findings have led to calls for renewed focus on aquifer recharge, increased environmental flow releases from barrages and revival of tributaries under national rejuvenation programs.