Water Resources(Unit - III, Chapter 2, Indian Geography)
- UniDrill
- Feb 25
- 5 min read
Updated: Mar 3
1. Water Resources of India: Availability and Distribution
India receives nearly 4,000 cubic km of precipitation annually from various sources . However, the total available surface water and replenishable groundwater is estimated at only 1,869 cubic km .
Due to topographical, hydrological, and other constraints, only about 60 per cent (1,122 cubic km) of this available water can actually be put to beneficial use .
I. Surface Water Resources
Surface water exists in four primary sources: rivers, lakes, ponds, and tanks .
River Systems: There are approximately 10,360 rivers and their tributaries in India, each longer than 1.6 km .
Catchment Potential: The mean annual flow in all the river basins in India is estimated to be 1,869 cubic km . However, the distribution is highly uneven.
Regional Variation: The Ganga, Brahmaputra, and Indus basins, which account for about one-third of the total catchment area, contain 60 per cent of India’s total surface water resources .
Utilization Constraints: In many Peninsular rivers like the Godavari, Krishna, and Kaveri, a much larger proportion of the water potential has been utilized compared to the Himalayan rivers, which still have vast untapped potential .
II. Groundwater Resources
The total replenishable groundwater resource in the country is about 432 cubic km .
Distribution: The Ganga and Brahmaputra basins have about 46 per cent of the total replenishable groundwater resources .
Utilization Levels: The level of groundwater utilization is relatively high in the river basins of north-western India (Punjab, Haryana, Rajasthan) and parts of South India (Tamil Nadu) .
State-wise Trends: States like Punjab, Haryana, and Rajasthan utilize a very high proportion of their groundwater, primarily for agriculture . Conversely, states like Chhattisgarh, Odisha, and Kerala utilize only a small fraction of their potential . If the current trend of high withdrawal continues, it will lead to severe water scarcity and environmental issues in high-utilization states .
III. Lagoons and Backwaters
India has a long coastline and a very indented coast in some states, leading to the formation of many lagoons and lakes .
States: These are most prominent in Kerala, Odisha, and West Bengal .
Usage: While these water bodies are generally brackish (salty), they are vital for fishing and irrigating certain varieties of paddy crops and coconut trees .
2. Water Demand and Utilization
India has traditionally been an agrarian economy, and about two-thirds of its population has been dependent on agriculture . Consequently, development goals post-Independence focused on expanding irrigation to ensure food security .
I. Sectoral Consumption
Agriculture: This is the dominant user of water in India. It accounts for 89 per cent of surface water and 92 per cent of groundwater utilization .
Industrial and Domestic: Currently, these sectors account for a small share (9% surface/5% ground for domestic; 2% surface/3% ground for industries) . However, as the country industrializes and urbanizes, their share of water demand is projected to rise significantly .
II. Demand for Irrigation
Irrigation is essential in India due to the spatio-temporal variability of rainfall .
Need: Large parts of the country are deficient in rainfall and drought-prone (e.g., North-western India and the Deccan Plateau) . Even in high-rainfall areas like West Bengal and Bihar, breaks in the monsoon or its early retreat can be detrimental to crops .
Green Revolution Support: The success of the Green Revolution in Punjab, Haryana, and Western Uttar Pradesh was entirely dependent on the expansion of irrigation .
Multi-cropping: Irrigation has made it possible to grow multiple crops in a year. In West Bengal and Bihar, farmers grow three crops of rice—aus, aman, and boro—in a single year provided irrigation is available .
3. Emerging Water Problems
The increasing demand for water, coupled with a growing population and deteriorating quality, has created a multifaceted crisis .
I. Deterioration of Water Quality
Water quality refers to the purity of water or water without unwanted foreign substances . Water becomes "polluted" when its concentration of suspended particles and organic/inorganic substances increases to the point where its self-purifying capacity is exceeded .
Sources of Pollution:
Industrial Effluents: Discharge of toxic chemical residuals, heavy metals, and dust from industries like leather, pulp, and chemicals .
Agricultural Runoff: Modern agriculture uses vast amounts of inorganic fertilizers, pesticides, and herbicides, which wash into rivers and lakes .
Domestic Sewage: Untreated waste from urban centers is often dumped directly into water bodies .
Highly Polluted Rivers: The Yamuna is the most polluted river in India between Delhi and Etawah . The Ganga faces severe pollution at Kanpur and Varanasi .
II. Scarcity and Depletion
Over-extraction of groundwater has led to a falling water table in many states .
Chemical Contamination: Depletion has increased the concentration of toxic substances. For example, over-withdrawal has led to high fluoride levels in parts of Rajasthan and Maharashtra, and arsenic contamination in West Bengal and Bihar .
Per Capita Availability: Due to population growth, the per capita availability of water is declining steadily .
4. Water Conservation and Management
Given that the supply of fresh water is limited and the demand is increasing, there is an urgent need for conservation .
I. Prevention of Pollution
Strict enforcement of environmental laws like the Water (Prevention and Control of Pollution) Act 1974 is necessary . However, effective implementation remains a challenge. Public awareness and community participation are critical for reducing ritualistic and domestic pollution in rivers .
II. Recycle and Reuse
Encouraging the use of low-quality water for purposes other than drinking can save vast amounts of fresh water .
Examples: Using reclaimed wastewater for cooling in thermal power plants, fire-fighting, or gardening .
III. Watershed Management
Watershed management involves the efficient management and conservation of all natural resources—land, water, plants, and animals—within a single hydrological unit (watershed) .
Objective: To bring about a balance between natural resources on one hand and society on the other .
Key Programs:
Haryali: A central government-sponsored project executed by Gram Panchayats with people’s participation .
Neeru-Meeru: (Water and You) program in Andhra Pradesh .
Arvary Pani Sansad: (Alwar, Rajasthan) involved the construction of various water-harvesting structures like johads and check dams .
IV. Rainwater Harvesting
Rainwater harvesting is a method to capture and store rainwater for various uses and to recharge groundwater aquifers .
Benefits: It is low-cost and eco-friendly; it stops soil erosion, improves water quality (by diluting pollutants like fluoride), and provides water security during dry seasons .
Traditional Methods: Include storage in tanks (tanka or kund) in Rajasthan .
Modern Compulsion: Tamil Nadu is the first state in India to make rooftop rainwater harvesting structures compulsory for all buildings .
V. National Water Policy 2012
The policy emphasizes the following priorities:
Treating water as an economic good to promote conservation .
Providing potable water to all human beings and livestock .
Promoting community-based management of water resources .
Prioritizing social equity and integrated water resource management .
5. Case Study: Success in Water Management
Ralegan Siddhi (Ahmadnagar, Maharashtra):
This village provides a classic example of transformation through watershed development .
The Problem: The village suffered from extreme poverty, illegal liquor trade, and severe water scarcity .
The Solution: Led by Anna Hazare, the community built percolation tanks and check dams to trap every drop of rain .
Outcome: The groundwater level rose significantly, allowing for multiple crops and the cultivation of diverse vegetables . The village became self-sufficient, and social evils like untouchability and alcoholism were eradicated through collective community action .
Summary Table for CUET Aspirants
Concept | Key Fact |
Total Utilisable Water | 1,122 cubic km |
Groundwater Potential | 432 cubic km |
Largest Water Consumer | Agriculture (89% of surface water) |
Most Polluted River | Yamuna (Delhi to Etawah stretch) |
Tamil Nadu Rule | Compulsory rooftop rainwater harvesting |
Watershed Success | Neeru-Meeru (AP) and Arvary Pani Sansad (Rajasthan) |
Main Groundwater Use | Irrigation for HYV crops (Green Revolution) |
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