What is water stress? How and why does it differ regionally in India?

Introduction

Water stress refers to a situation where the demand for water exceeds the available supply or when poor quality restricts its usage. It is often measured using indicators like per capita water availability (below 1,700 m³ annually indicates water stress) and the Water Stress Index. India, with 18% of the global population but only 4% of global freshwater resources, faces significant water stress challenges.

Value Addition Block — Key Indicators of Water Stress in India

Key Indicators of Water Stress in India

• Per Capita Water Availability: ~1,500 m³/year (2021, Ministry of Jal Shakti).
• Groundwater Depletion: India is the largest extractor of groundwater (~25% of global extraction).
• Rainfall Variability: Uneven monsoon distribution, with 75% of annual rainfall concentrated in 4 months.
• Water Quality: 70% of surface water is polluted (CPCB).

Causes of Regional Variations in Water Stress in India

1. Climatic and Geographical Factors

• Rainfall Distribution: The western and northwestern regions (e.g., Rajasthan, Gujarat) receive less than 500 mm of annual rainfall, while the northeastern states receive over 2,000 mm.
• Topography: Hilly regions (e.g., Himalayan states) face challenges in water storage and accessibility despite high rainfall.
• Seasonal Variability: Monsoon-dependent regions like peninsular India experience acute water stress during non-monsoon months.

2. Population Density and Urbanization

• High Population Pressure: States like Uttar Pradesh and Bihar have high population densities, leading to over-extraction of water resources.
• Urban Water Demand: Cities like Delhi and Bengaluru face severe water stress due to rapid urbanization and inadequate infrastructure.

3. Agricultural Practices

• Water-Intensive Crops: Cultivation of crops like sugarcane and paddy in water-scarce regions (e.g., Maharashtra, Punjab) exacerbates stress.
• Inefficient Irrigation: Over-reliance on groundwater for irrigation (89% of groundwater use) depletes aquifers, especially in Punjab and Haryana.

4. Groundwater Depletion

• Over-Extraction: States like Rajasthan, Gujarat, and Tamil Nadu face critical groundwater depletion due to excessive reliance on borewells.
• Poor Recharge Mechanisms: Lack of rainwater harvesting and natural recharge systems worsens the situation.

5. Water Quality Issues

• Pollution: Industrial effluents and untreated sewage pollute rivers like the Ganga and Yamuna, reducing usable water.
• Salinity: Coastal regions like Gujarat and Odisha face salinity intrusion in groundwater due to over-extraction.

Impacts of Regional Water Stress

1. Economic Impacts

• Agricultural Losses: Water scarcity affects crop yields, especially in drought-prone regions like Marathwada.
• Industrial Slowdown: Water-intensive industries in regions like Chennai face operational challenges.

2. Social Impacts

• Migration: Water scarcity drives rural-to-urban migration, as seen in Bundelkhand.
• Health Issues: Poor water quality leads to diseases like cholera and diarrhea, especially in eastern India.

3. Environmental Impacts

• Desertification: Over-extraction and deforestation accelerate desertification in Rajasthan.
• Loss of Biodiversity: Reduced water availability affects aquatic ecosystems, such as in the Western Ghats.

Way Forward

1. Sustainable Water Management

• Promote micro-irrigation techniques like drip and sprinkler systems to reduce water wastage.
• Implement rainwater harvesting and groundwater recharge projects, especially in urban areas.

2. Policy and Governance

• Enforce the National Water Policy (2012) to ensure equitable water distribution.
• Strengthen inter-state river water sharing agreements to reduce regional disparities.

3. Community Participation

• Encourage local water user associations for better management of resources.
• Promote traditional water conservation practices, such as baolis and tankas in Rajasthan.

4. Technological Interventions

• Use GIS mapping for real-time monitoring of water resources.
• Develop desalination plants in coastal regions to address salinity issues.

Conclusion

Addressing water stress in India requires a multi-pronged approach involving sustainable practices, robust governance, and community participation. Achieving SDG 6 (Clean Water and Sanitation) and ensuring water security for all will be critical for India's socio-economic and environmental well-being.