Understanding Groundwater: Its Role and Management in India

Understanding Groundwater: A Vital Resource

Groundwater serves as a crucial water supply source in India, stored within underground aquifers. This resource is indispensable for irrigation and daily living needs, playing a critical role in sustaining agriculture and household water consumption.

The Significance of Groundwater in India

In India, groundwater is pivotal for various reasons:

• Irrigation: A significant portion of India's agricultural sector relies on groundwater to support crop growth.
• Daily Needs: Millions of residents depend on groundwater for drinking and other domestic purposes.

The Current State of Groundwater Resources

The balance between groundwater extraction and natural recharge is currently under threat. As the largest extractor worldwide, India uses 25% of global groundwater supplies. Unsustainable withdrawal rates, pollution, and climate change factors contribute to worrying depletion trends.

Natural Groundwater Recharge Mechanisms

Groundwater is naturally replenished through several processes:

• Precipitation: Rain and snowmelt infiltrate the soil, gradually percolating into aquifers.
• Surface Water: Rivers, lakes, and wetlands contribute as their waters seep downward.
• Interflow and Baseflow: Water moves laterally through soil layers, sustaining river flows.

Factors such as soil type, vegetation, topography, and climate influence these recharge processes.

Factors Influencing Natural Recharge

Several elements impact natural groundwater recharge:

• Soil Type: Permeable soils facilitate faster water infiltration compared to clayey ones.
• Vegetation: Plant roots create pathways that enhance water infiltration.
• Topography: Gentle slopes help retain water, promoting increased infiltration.
• Climate: Rainfall patterns have a direct effect on recharge rates.

Methods for Artificial Groundwater Recharge

Artificial recharge practices include:

• Check Dams and Percolation Ponds: These structures slow water flow, increasing seepage.
• Recharge Wells: Directly inject water into aquifers.
• Rainwater Harvesting: Collects and stores rainwater, directing it into the ground.
• Canal Irrigation: Water from canals seeps underground.
• Aquifer Storage and Recovery (ASR): Involves injecting treated water or excess monsoon runoff into aquifers, aiding in replenishment. This technique is employed in cities like Chennai, Rajasthan, and Maharashtra.
• Floodwater Management: In flood-prone states such as Bihar, West Bengal, and Uttar Pradesh, excess river water is diverted into recharge structures like artificial wetlands and retention basins to restore groundwater levels.

Aquifer Storage and Recovery (ASR) in Practice

Aquifer Storage and Recovery (ASR) entails injecting treated water or surplus monsoon runoff into aquifers for future use, thus helping replenish groundwater reserves.

Floodwater Management Techniques for Recharge

In regions prone to flooding, such as Bihar, West Bengal, and Uttar Pradesh, excess river water is systematically directed into recharge structures like artificial wetlands and retention basins. This approach aids in restoring and maintaining groundwater levels effectively.