Relevance (UPSC): GS-I Geography (Hydrology) | GS-III Environment & Agriculture

Recent research on river–aquifer interactions shows that the lean-season flow of the Ganga is driven mainly by groundwater baseflow, not glacier melt. Glaciers feed the headwaters, but from the Himalayan foothills to the plains, the river largely stays alive in winter because aquifers in the floodplain slowly discharge into the channel. Over-pumping can convert stretches from gaining to losing reaches—water leaks from the river to the ground.

Why This Matters

• Water security: Most basin people, farms, and cities depend on dry-season flows sustained by groundwater.
• Climate lens: Glacier retreat affects headwaters, but monsoon recharge and aquifer health determine plains’ flows.
• Current risk: Over-extraction for paddy/sugarcane, sand mining, and embankments cut recharge zones, reducing baseflow.

Policy Hooks You Must Know

• Atal Bhujal Yojana: Community-led demand management in stressed aquifers.
• NAQUIM: National Aquifer Mapping & Management; guides managed aquifer recharge.
• Namami Gange + e-flow norms: Mandate minimum releases from barrages.
• PM Krishi Sinchayee Yojana: Crop-water reforms; promote micro-irrigation and crop diversification.
• CGWA guidelines: Groundwater regulation; floodplain zoning; wetland restoration.

Practical Fixes

• Restore floodplain recharge: protect natural levees, wetlands, abandoned channels; stop hard encroachments.
• Scale managed aquifer recharge: check-dams, trenches, percolation ponds linked to NAQUIM plans.
• Shift water-hungry crops away from critical blocks; incentivize micro-irrigation and direct-seeded rice.
• Enforce e-flows at barrages; curb illegal sand mining that lowers riverbed and drains aquifers.
• Meter large extractions; publish block-level water accounts; involve gram sabhas in allocation.

Key Terms

• Baseflow: Slow groundwater discharge sustaining rivers in dry periods.
• Gaining/Losing reach: River receives from or loses water to aquifer.
• Floodplain aquifer: Shallow, highly rechargeable sands along the river.
• Managed aquifer recharge: Planned infiltration to refill groundwater.
• Environmental flow: Minimum water left in the river for ecology.

Exam Hook

In answers on Ganga rejuvenation, argue that saving the river means saving its aquifers: protect floodplains, recharge, regulate pumping, and enforce e-flows. Glaciers alone cannot keep the river alive.

UPSC Prelims Practice

Consider the following statements:

1. In the middle and lower Ganga basin, lean-season river flow is sustained largely by groundwater baseflow.
2. Managed aquifer recharge helps increase baseflow in future dry months.
3. Environmental-flow norms require minimum releases from upstream structures.

Answer: 1, 2 and 3

One-line wrap: To keep the Ganga flowing in winter, refill and protect floodplain aquifers—because the river’s true lifeline runs underground.