Sources of the Ganges River: Glaciers, Rain, Groundwater, Tributaries

Fourfold Supply

1. Glacial Melt – Gangotri, Satopanth, Bhagirath Kharak glaciers (Gaumukh source) provide summer baseflow.
2. Monsoon Rainfall – June–September rains swell the river dramatically; 80% of annual flow.
3. Groundwater – Alluvial aquifers sustain dry-season flow (baseflow) via seepage.
4. Major Tributaries – Yamuna (largest), Ghaghara, Gandak, Kosi, Son, Gomti, Damodar—each with their own basins, multiplying total discharge.

Seasonal Rhythm

Pre-monsoon (Apr–May): glacial melt. Monsoon (Jun–Sep): flood pulse. Post-monsoon (Oct–Nov): recession. Dry (Dec–Mar): groundwater + glacial trickle.

Pressures

Climate change (glacier retreat), over-extraction (irrigation, cities), pollution, and dams threaten this lifeline for 400+ million people.