Geography: Class 12 (Part 2) — Chapter 4: Water Resources

The distribution of global resources in India is summarized below:

There are four major sources of surface water: rivers, lakes, ponds, and tanks. The country has around 10,360 rivers and their tributaries longer than 1.6 km each.

• The mean annual flow in all river basins is estimated to be 1,869 cubic km, but only about 690 cubic km (32%) can be utilized due to topographical and hydrological constraints.
• Rivers like the Ganga, Brahmaputra, and Indus have massive catchment areas.
• The Ganga, Brahmaputra, and Barak basins contain 60% of the total surface water resources despite covering only one-third of the national area.

The total replenishable groundwater resources in India are about 432 cubic km.

• High Utilisation States: Punjab, Haryana, Rajasthan, and Tamil Nadu.
• Moderate Utilisation States: Gujarat, Uttar Pradesh, Bihar, Tripura, and Maharashtra.
• Low Utilisation States: Chhattisgarh, Odisha, and Kerala.

India's long, indented coastline has led to the formation of numerous lagoons and lakes, particularly in states like Kerala, Odisha, and West Bengal. Although generally brackish, this water is utilized for fishing and irrigating specific varieties of paddy crops and coconut trees.

The allocation of water resources across different sectors highlights the dominance of agriculture:

Irrigation is essential due to the high spatio-temporal variability of rainfall in India. Large tracts of the country, such as North-western India and the Deccan plateau, are dry and drought-prone.

• Certain crops like rice, sugarcane, and jute require high amounts of water that can only be sustained through irrigation.
• The Green Revolution strategy succeeded in Punjab, Haryana, and western Uttar Pradesh largely due to developed irrigation systems.
• Over-irrigation has led to severe environmental issues, including groundwater depletion, increased fluoride concentration in Rajasthan and Maharashtra, and arsenic contamination in parts of West Bengal and Bihar.

Launched during 2015-16, PMKSY aims to provide protective irrigation to all agricultural farms in the country. Key objectives include:

• Enhancing physical access to water on farms (Har Khet Ko Pani).
• Improving on-farm water use efficiency (Per Drop More Crop).
• Promoting sustainable water conservation practices.

Water quality refers to the purity of water, free from unwanted foreign substances. Toxic substances entering water bodies from industrial, agricultural, and domestic sources degrade aquatic systems and seep into groundwater aquifers.

The Central Pollution Control Board (CPCB), in collaboration with State Pollution Control Boards, monitors national water quality.

• The Yamuna River is the most polluted river in the country, particularly between Delhi and Etawah.
• Other highly polluted rivers include the Sabarmati at Ahmedabad, the Gomti at Lucknow, the Kali, the Adyar, the Cooum, the Vaigai at Madurai, and the Musi at Hyderabad.
• Legislative Frameworks: The Water (Prevention and Control of Pollution) Act 1974, the Environment Protection Act 1986, and the Water Cess Act 1977 aim to curb pollution, though implementation remains a challenge.

Recycling wastewater is a highly effective way to improve freshwater availability. Reclaimed water of lesser quality can be used by industries for cooling or fire-fighting, and domestic wastewater can be reused for gardening.

Watershed management refers to the efficient management and conservation of surface and groundwater resources, involving runoff prevention, storage, and groundwater recharge.

• Haryali: A central government-sponsored watershed development project executed by Gram Panchayats with public participation.
• Neeru-Meeru: A water conservation programme in Andhra Pradesh.
• Arvary Pani Sansad: A community-led water harvesting initiative in Alwar, Rajasthan.
• Ralegan Siddhi Case Study: A small village in Ahmadnagar, Maharashtra, transformed from poverty to self-reliance through community-led watershed management, voluntary labor (Shramdaan), and sustainable farming.

Rainwater harvesting is a low-cost, eco-friendly method to capture and store rainwater for direct use or groundwater recharge.

• Traditional methods include constructing Kunds or Tankas (covered underground tanks) in Rajasthan.
• Modern methods focus on rooftop rainwater harvesting and open space collection.
• Tamil Nadu has made rainwater harvesting structures compulsory for all building constructions.

Key features of the policy include:

• Creating a national water framework law.
• Prioritizing drinking water and sanitation, followed by food security and ecological needs.
• Treating water as an economic good to promote conservation.
• Designing climate-resilient water infrastructure.

An initiative launched by the Government of India to secure water availability through active community involvement. Key activities include:

1. Creating a Jal Gram in each of the 672 districts.
2. Identifying model command areas of about 1,000 hectares.
3. Abating pollution through artificial recharge and constructing arsenic-free wells.
4. Generating mass awareness through media and school programs.