Chapter 4 Water Resources

Introduction

Water is a critical resource, fundamental for life and crucial for various economic activities. While Earth has abundant water, primarily in oceans, only a small fraction is available as freshwater for human use. This freshwater is a cyclic resource, constantly renewed through processes like the water cycle.

The availability of freshwater varies significantly across different regions and seasons. Increasing population and rapid economic development are leading to a surge in water demand. Simultaneously, supplies are shrinking due to over-utilisation and pollution of existing sources. This growing gap between demand and supply, coupled with regional disparities in availability, is causing increasing tensions and disputes over water sharing and control among communities, regions, and states.

Given the scarcity and increasing competition, effective assessment, efficient use, and conservation of water resources are essential for ensuring sustainable development and avoiding future conflicts. This chapter examines India's water resources, their geographical distribution, how they are used across different sectors, and methods for conservation and management.

Water Resources Of India

India holds approximately 2.45% of the world's land area and about 4% of the world's total water resources, but it is home to over 17% of the global population. This highlights the significant per capita water scarcity challenge the country faces.

The total water received annually from precipitation (rain and snow) in India is estimated to be around 4,000 cubic kilometres. However, not all of this is readily usable. The combined availability from surface water sources and replenishable groundwater is estimated at 1,869 cubic km. Due to limitations posed by topography, hydrology, and technology, only about 60% of this available water, amounting to 1,122 cubic km, is considered utilisable for beneficial purposes.

Surface Water Resources

The main sources of surface water in India are its rivers, lakes, ponds, and tanks. India has a vast network of rivers, with about 10,360 rivers and their tributaries, each longer than 1.6 km.

The total mean annual flow in all these river basins is estimated at 1,869 cubic km. However, only around 32% (about 690 cubic km) of this surface water can be effectively utilised. This is due to geographical and technical constraints that make harnessing the full flow difficult.

River flow is primarily determined by the size of its drainage basin (catchment area) and the amount of rainfall within that area. Rivers in India, such as the Ganga, Brahmaputra, and Indus, have huge catchment areas. The Ganga, Brahmaputra, and Barak basins, despite accounting for only about one-third of the country's total area, possess around 60% of the total surface water resources, thanks to high precipitation in their catchment regions. While the annual water flow in many South Indian rivers like the Godavari, Krishna, and Kaveri has been largely harnessed, significant potential still exists in the Brahmaputra and Ganga basins.

Groundwater Resources

Groundwater is another significant source of freshwater, stored beneath the Earth's surface in aquifers. The total replenishable groundwater resources in India are estimated to be around 432 cubic km.

The level of groundwater utilisation varies regionally. It is relatively high in the river basins located in the north-western part of the country and in some parts of South India. States like Punjab, Haryana, Rajasthan, and Tamil Nadu show very high rates of groundwater abstraction, often exceeding their replenishable limits in many areas.

In contrast, states such as Chhattisgarh, Odisha, and Kerala utilise only a small portion of their groundwater potential. Gujarat, Uttar Pradesh, Bihar, Tripura, and Maharashtra use their groundwater resources at a moderate rate.

If the current trends of groundwater over-utilisation continue, particularly in vulnerable regions, the demand for water will outstrip supply. Such a situation could severely impede development and potentially lead to social unrest and disruptions.

Lagoons And Backwaters

India's extensive coastline, especially in certain states with indented shorelines, features numerous lagoons and backwaters. States like Kerala, Odisha, and West Bengal have significant surface water resources contained within these coastal water bodies. Although the water in lagoons and backwaters is generally brackish (a mix of fresh and saltwater), it is used for specific purposes. These include fishing activities and irrigating certain salt-tolerant varieties of crops like paddy and coconut palms.

Water Demand And Utilisation

India has historically been, and remains largely, an agrarian economy, with a majority of its population dependent on agriculture. This dependence heavily influences the country's water demand patterns.

Demand Of Water For Irrigation

Agriculture is by far the largest consumer of water in India, dominating both surface water and groundwater utilisation. The development of irrigation systems has been a top priority since the initial Five Year Plans to boost agricultural production. Major multi-purpose river valley projects (e.g., Bhakra-Nangal, Hirakud, Damodar Valley, Nagarjuna Sagar, Indira Gandhi Canal Project) were undertaken to provide assured water supply for farming.

Currently, agriculture accounts for about 89% of total surface water utilisation and a significant 92% of total groundwater utilisation. In comparison, the industrial sector uses only 2% of surface water and 5% of groundwater, while the domestic sector uses 9% of surface water and a smaller proportion of groundwater. The agricultural sector's share in total water use is substantially higher than other sectors. However, as India develops further, the water demand from the industrial and domestic sectors is expected to increase.

The primary use of water in agriculture is for irrigation. Irrigation is essential due to the uneven distribution of rainfall across India, both spatially and over time. Large parts of the country are drought-prone and receive insufficient rainfall, particularly in the north-western regions and the Deccan Plateau. Moreover, winter and summer seasons are largely dry, making agriculture difficult without assured irrigation during these periods. Certain crops, such as rice, sugarcane, and jute, have very high water requirements that can only be met through irrigation.

Irrigation enables multiple cropping in a year and significantly increases agricultural productivity compared to rainfed lands. Furthermore, the success of High Yielding Varieties (HYVs) of crops, introduced during the Green Revolution, hinges on a regular and sufficient supply of moisture, which is made possible only through developed irrigation systems. This is why the Green Revolution was largely successful in irrigated regions like Punjab, Haryana, and western Uttar Pradesh.

In Punjab, Haryana, and western Uttar Pradesh, over 85% of the net sown area is under irrigation. Wheat and rice, in particular, are extensively grown with irrigation in these states. Wells and tubewells are major sources, accounting for a large proportion of the irrigated area (76.1% in Punjab, 51.3% in Haryana). This high reliance on groundwater has resulted in its significant depletion in many areas, leading to declining groundwater tables. Over-withdrawal in some states like Rajasthan and Maharashtra has increased fluoride concentration in groundwater, while it has led to increased arsenic concentration in parts of West Bengal and Bihar.

Pradhan Mantri Krishi Sinchayee Yojana (PMKSY)

Launched by the Central Government in 2015-16, the Pradhan Mantri Krishi Sinchayee Yojana (PMKSY) is a major program aimed at ensuring that every agricultural farm in India has access to some form of protective irrigation. The overarching vision is to enhance rural prosperity by providing assured water supply for farming.

Key objectives of PMKSY include:

• Increasing physical access to water on farms and expanding the area under assured irrigation ("Har khet ko pani" - Water to every field).
• Promoting integrated management of water sources, distribution networks, and efficient water use through appropriate technologies and practices.
• Improving on-farm water use efficiency to minimize wastage and enhance water availability in terms of duration and extent, promoting "Per drope more crop" using micro-irrigation and water-saving technologies.
• Introducing and encouraging sustainable water conservation practices.
• Ensuring the integrated development of rain-fed areas through soil and water conservation measures, groundwater regeneration, and providing diverse livelihood options.

Emerging Water Problems

India faces increasingly severe water challenges due to the dual pressures of a growing population, which reduces per capita water availability, and the widespread pollution of existing water resources, which limits the availability of usable water.

Deterioration Of Water Quality

Water quality refers to the purity of water, meaning water free from unwanted foreign substances. Water sources become polluted when foreign matters, such as micro-organisms, chemicals, and waste from industrial, agricultural, and domestic sources, enter them. These pollutants degrade water quality, making it unfit for human use and harming aquatic ecosystems. Pollutants in lakes, streams, and rivers can dissolve or remain suspended. They can also seep down to contaminate groundwater sources.

The Central Pollution Control Board (CPCB), in collaboration with State Pollution Control Boards, monitors the water quality of national aquatic resources. Data indicates that organic and bacterial contamination are the primary sources of river pollution in India. Some rivers are severely polluted, such as the Yamuna between Delhi and Etawah, the Sabarmati at Ahmedabad, the Gomti at Lucknow, the Kali, the Adyar, the Cooum, the Vaigai at Madurai, the Musi of Hyderabad, and the Ganga at Kanpur and Varanasi.

Groundwater pollution is also a concern in various parts of the country, resulting from high concentrations of heavy/toxic metals, fluoride, and nitrates.

Despite legislative efforts like the Water (Prevention and Control of Pollution) Act 1974 and the Environment Protection Act 1986, effective implementation has been lacking. For example, in 1997, a significant number of polluting industries were located along rivers and lakes. The Water Cess Act, 1977, aimed at reducing pollution, has also had limited impact. There is an urgent need to raise public awareness about the importance of water quality and the impacts of pollution, and to encourage public action to reduce pollutants from all sources.

Water Conservation And Management

With freshwater availability decreasing and demand increasing, conservation and effective management of water are critical for sustainable development. As desalination of ocean water is currently cost-prohibitive for large-scale use, India must implement prompt policies, laws, and measures for conservation. This includes developing water-saving technologies, preventing pollution, and adopting integrated approaches like watershed development, rainwater harvesting, water recycling and reuse, and conjunctive use of water resources.

Prevention Of Water Pollution

Preventing pollution is a direct way to preserve usable water resources. Rivers are particularly vulnerable, degrading rapidly in plains where water is intensively used and receives effluents from various sources. Pollutant concentration is especially high during summer when river flow is low. While laws exist, their effective implementation and public awareness campaigns are crucial to control pollution from agricultural, domestic, and industrial discharges.

Recycle And Reuse Of Water

Recycling and reusing water can significantly improve freshwater availability. Water of lesser quality, such as treated wastewater, can be used by industries for purposes like cooling and fire fighting, reducing their demand for fresh water. In urban areas, water used for bathing or washing can be collected and reused for non-potable purposes like gardening or washing vehicles. This conserves higher quality water for drinking. Although currently practiced on a limited scale, there is vast potential for expanding water recycling and reuse.

Watershed Management

Watershed management focuses on the efficient management and conservation of surface and groundwater resources within a specific drainage basin. It involves measures to prevent water runoff and promote storage and recharge of groundwater through structures like percolation tanks and recharge wells. More broadly, it includes conserving, regenerating, and judiciously using all natural (land, water, plants, animals) and human resources within a watershed, aiming for a balance between the environment and the community. Successful watershed management relies heavily on active community participation.

Both Central and State Governments in India have initiated watershed development and management programs, often involving non-governmental organisations. Programs like Haryali, sponsored by the Central Government and executed by Gram Panchayats with community involvement, aim to conserve water for various uses including drinking, irrigation, fisheries, and afforestation.

Atal Bhujal Yojana (Atal Jal) is being implemented in water-stressed areas across seven states to improve groundwater management. A key focus is on encouraging behavioral change in communities from excessive consumption to conservation and smart water practices. Other successful examples of community-led initiatives include Neeru-Meeru (Water and You) in Andhra Pradesh and Arvary Pani Sansad in Alwar, Rajasthan, which have constructed water-harvesting structures with people's participation. Tamil Nadu has made rooftop rainwater harvesting structures mandatory for all buildings.

While watershed development projects have shown success in rejuvenating environments and economies in some areas, many are still in early stages. Increased public awareness about the benefits of watershed development and adopting an integrated water resource management approach are crucial for ensuring sustainable water availability nationwide.

Watershed Development In Ralegan Siddhi, Ahmadnagar, Maharashtra: A Case Study

Ralegan Siddhi, a village in Ahmadnagar district, Maharashtra, serves as a significant example of successful watershed development. Faced with poverty and social issues in 1975, the village was transformed under the leadership of a retired army personnel who championed watershed development.

The transformation was based on principles of community participation, emphasizing voluntary labor (reducing dependence on government aid and socializing costs), social reforms (family planning, banning dowry, caste discrimination, untouchability, liquor prohibition), and environmental protection (preventing open grazing, felling trees). An initial success with a percolation tank filling up wells below demonstrated the potential and built community trust.

Changes in farming practices were also introduced, banning water-intensive crops like sugarcane and promoting low-water-requiring crops like pulses and oilseeds. Local governance adopted consensus-based elections, and informal courts (Nyay Panchayats) were established. The village also achieved self-reliance in building infrastructure like schools through community resources.

Today, Ralegan Siddhi has sufficient water, flourishing agriculture (though facing challenges like high fertilizer/pesticide use), and enhanced livelihoods, demonstrating the potential of integrated watershed management and community action, although long-term sustainability by future generations remains a question.

Rainwater Harvesting

Rainwater harvesting is a method of capturing and storing rainwater or using it to recharge groundwater aquifers. It is an environmentally friendly and low-cost technique. It involves directing rainwater runoff into wells, pits, or underground tanks.

Benefits of rainwater harvesting include increasing local water availability, helping to check the decline of groundwater levels, improving groundwater quality by diluting contaminants (fluoride, nitrates), preventing soil erosion and urban flooding, and mitigating saltwater intrusion in coastal aquifers. Traditional methods using surface storage bodies (lakes, ponds, tanks) have been practiced for centuries. In Rajasthan, traditional structures like Kund or Tanka (covered underground tanks) are used.

There is significant scope for expanding rainwater harvesting, particularly through rooftop harvesting and capturing runoff from open spaces. This can reduce community reliance on groundwater for domestic use and save energy needed for pumping groundwater, as recharge raises the water table. Rainwater harvesting is being promoted on a large scale, especially in urban areas where water demand often exceeds supply. Some states have made such structures mandatory.

Highlights Of India’S National Water Policy 2012

The National Water Policy 2012 provides a framework for the conservation, development, and management of India's water resources with a unified national perspective. Key recommendations include:

• Recognizing the need for a national water framework law and comprehensive legislation for the optimum development of inter-State rivers.
• Treating water as an economic good, after prioritizing its allocation for essential needs like safe drinking water, sanitation, food security, supporting the poor, and maintaining minimum ecosystem flow.
• Emphasizing adaptation strategies for water resource management and infrastructure design in light of climate change.
• Developing systems for benchmarking water uses (water footprints) and water auditing to ensure efficient use.
• Recommending the removal of large disparities in water supply stipulations between urban and rural areas.
• Encouraging community participation in the management of water resources projects and services.

Jal Kranti Abhiyan (2015-16)

Launched in 2015-16, the Jal Kranti Abhiyan is a government initiative aimed at ensuring water security across India by focusing on increasing per capita water availability. Recognizing water as a limited, recyclable resource facing increasing demand and climate stress, the Abhiyan seeks to leverage traditional water conservation knowledge and involve local bodies, NGOs, and citizens.

Key activities include selecting 'Jal Grams' (water-stressed villages) for concentrated efforts, identifying model command areas, focusing on pollution abatement, promoting water conservation and artificial recharge, addressing groundwater pollution (including constructing Arsenic-free wells), and conducting mass awareness campaigns through various media and school competitions. The Abhiyan's goal is to support livelihood and food security through comprehensive water security measures.