Water Resources

Introduction

Water is one of the most vital natural resources on Earth. It is the foundation of life, covering about 71% of the planet’s surface, yet only 2.5% is fresh water, and less than 1% is easily accessible for human use. From quenching thirst to growing food, generating power, supporting industries, maintaining biodiversity, and regulating the climate, water resources form the lifeline of civilizations. Without water, survival is impossible.

Throughout history, human settlements have flourished along rivers—such as the Nile, Indus, Tigris-Euphrates, and Ganges—because water provides not only drinking supply but also fertile soil, transportation, and cultural development. In modern times, with rapid population growth, urbanization, and industrialization, the demand for water has increased dramatically. However, water resources are under tremendous stress due to overuse, pollution, mismanagement, and climate change. Therefore, understanding water resources, their distribution, importance, problems, and management is essential for sustainable development.

Water Resources: Meaning and Types

Meaning

Water resources refer to the sources of water that are useful or potentially useful to humans for domestic, agricultural, industrial, recreational, and environmental purposes. These include both surface and groundwater sources.

Types of Water Resources

• Surface Water
  • Rivers, lakes, reservoirs, ponds, streams, glaciers.
• Groundwater
  • Water stored in aquifers beneath the Earth’s surface.
• Rainwater
  • Precipitation that replenishes both surface and groundwater.
• Ocean Water
  • Though saline, oceans are used for desalination, fisheries, navigation, and energy (tidal/wave).

Distribution of Water on Earth

• Total water on Earth: ~1,386 million cubic kilometers.
• Oceans: 97.5% (saline, unsuitable for drinking/irrigation without treatment).
• Freshwater: 2.5%, but only:
  • 68.7% is locked in glaciers and ice caps.
  • 30.1% is groundwater.
  • 0.9% in swamps, rivers, and lakes.
  • Less than 0.01% is easily accessible for human use.

This highlights the scarcity of usable freshwater, despite water being abundant globally.

Water Resources in India

India is blessed with a large network of rivers, lakes, groundwater, and rainfall. However, uneven distribution creates water stress in many areas.

• Average annual precipitation: 4000 billion cubic meters (bcm).
• Usable water resources: about 1123 bcm (690 bcm surface water + 433 bcm groundwater).
• Major river basins: 20 (e.g., Ganga, Brahmaputra, Godavari, Krishna, Mahanadi, Narmada, Tapi).
• Groundwater: Accounts for nearly 60% of irrigation and 85% of rural drinking water needs.

Yet, India faces seasonal and regional water scarcity due to uneven rainfall (monsoon-dependent) and increasing demand.

Importance of Water Resources

• Domestic Use: Drinking, cooking, cleaning, sanitation.
• Agriculture: Irrigation for crops; India is largely monsoon-dependent, hence irrigation is critical.
• Industry: Cooling, processing, cleaning, hydro-power generation.
• Transportation: Inland waterways, shipping, navigation.
• Energy: Hydropower is a major renewable energy source.
• Ecological Balance: Wetlands, forests, and aquatic biodiversity depend on water.
• Cultural & Religious Role: Rivers like the Ganga, Yamuna, and Godavari are revered.

Water Use in India

• Agriculture: 80-85% of total freshwater use.
• Industry: 8-10%.
• Domestic & other uses: 6-7%.

This heavy dependence of agriculture on water highlights the need for efficient irrigation systems.

Problems of Water Resources

1. Water Scarcity

• Increasing population → higher demand.
• Declining groundwater levels due to over-extraction.
• Unequal distribution of rainfall (arid regions like Rajasthan vs. flood-prone areas like Assam).

2. Water Pollution

• Industrial effluents, sewage, agricultural runoff (pesticides, fertilizers).
• Rivers like Yamuna and Ganga face severe pollution.

3. Groundwater Depletion

• Tube-well irrigation has led to over-extraction.
• States like Punjab, Haryana, Gujarat face groundwater crisis.

4. Floods and Droughts

• Seasonal monsoon → floods in some regions, droughts in others.
• Lack of proper storage and management infrastructure.

5. Climate Change

• Altered rainfall patterns, melting glaciers, rising sea levels.

Water Management and Conservation

Traditional Water Harvesting Systems

• Rajasthan: Tankas, johads.
• Maharashtra: Bawlis.
• Himachal & J&K: Kulhs (small canals).
• Tamil Nadu: Eri (tank system).

These methods show the wisdom of sustainable use.

Modern Conservation Measures

• Rainwater Harvesting: Collecting and storing rooftop rainwater.
• Watershed Management: Conserving soil and water together.
• Interlinking of Rivers: Proposed national project to balance water surplus and deficit areas.
• Micro-Irrigation: Drip and sprinkler systems to save water.
• Check Dams & Recharge Pits: Replenish groundwater.
• Afforestation: Prevents runoff, increases infiltration.

Irrigation in India

Sources of Irrigation

• Wells & Tube Wells: Major source (over 40%).
• Canals: Especially in North India (Punjab, Haryana, Uttar Pradesh).
• Tanks: Common in peninsular India.
• Modern methods: Drip, sprinkler irrigation.

Problems in Irrigation

• Overuse of groundwater.
• Waterlogging and salinity in canal-irrigated areas.
• Poor maintenance of irrigation infrastructure.

Hydropower in India

Hydropower is a renewable and clean source of energy.

• India’s potential: ~1,45,000 MW.
• Installed capacity: ~46,000 MW (as of 2023).
• Major projects: Bhakra Nangal, Tehri, Sardar Sarovar, Hirakud, Nagarjuna Sagar.

Challenges: displacement of people, ecological impacts, siltation.

International Issues of Water Resources

• India-Bangladesh: Ganga water sharing at Farakka Barrage.
• India-Pakistan: Indus Water Treaty (1960).
• India-Nepal: Sharing of rivers like Kosi, Gandak.

These disputes highlight the political dimension of water.

Government Initiatives for Water Management

• Jal Jeevan Mission (2019): Tap water to every rural household by 2024.
• Namami Gange Programme: Clean and rejuvenate Ganga.
• Atal Bhujal Yojana: Sustainable groundwater management.
• National Water Mission: “More crop per drop” approach.
• Pradhan Mantri Krishi Sinchai Yojana (PMKSY): Irrigation efficiency.

Future Prospects

• Sustainable Agriculture: Promote water-efficient crops.
• Technology: IoT sensors, AI-based irrigation.
• Desalination Plants: Especially in coastal cities like Chennai.
• Recycling & Reuse: Treated wastewater for industry and irrigation.
• Awareness Campaigns: Change in lifestyle and consumption.

Conclusion

Water is the blue gold of the 21st century. While Earth has abundant water, the share of usable freshwater is extremely limited. With population growth, urbanization, and climate change, water stress will become one of the biggest global challenges. Countries like India must focus on sustainable water management, efficient irrigation, pollution control, rainwater harvesting, and community participation.