<h5 id="water-resources-of-india">Water Resources of India</h5> <ul> <li>India has approximately 2.45% of the world’s surface area, 4% of its water resources, and 16% of its population.</li> <li>The country receives about 4,000 cubic km of water from precipitation annually.</li> <li>The utilizable water from surface water and replenishable groundwater is 1,869 cubic km.</li> <li>Only 60% of this total, i.e., 1,122 cubic km, can be used beneficially.</li> <li>Therefore, the total utilisable water resource in India is 1,122 cubic km.</li> </ul> <p>======</p> <h5 id="surface-water-resources">Surface Water Resources</h5> <ul> <li>Surface water resources are primarily sourced from rivers, lakes, ponds, and tanks.</li> <li>In India, there are approximately 10,360 rivers with a length greater than 1.6 km, having a mean annual flow of 1,869 cubic km.</li> <li>Only about 32% (690 cubic km) of the available surface water can be utilized due to topographical, hydrological, and other constraints.</li> <li>The water flow in a river is dependent on the size of its catchment area and rainfall within the area; rivers like the Ganga, Brahmaputra, and Indus have huge catchment areas, accounting for 60% of the total surface water resources.</li> <li>While much of the annual water flow in south Indian rivers has been harnessed, it is yet to be done in the Brahmaputra and Ganga basins.</li> </ul> <p>======</p> <h5 id="groundwater-resources">Groundwater Resources</h5> <ul> <li>The total replenishable groundwater resources in the country are approximately 432 cubic km.</li> <li>Groundwater utilization is high in the north-western region and parts of south India, particularly in Punjab, Haryana, Rajasthan, and Tamil Nadu.</li> <li>Some states, such as Chhattisgarh, Odisha, Kerala, utilize only a small proportion of their groundwater potentials.</li> <li>States like Gujarat, Uttar Pradesh, Bihar, Tripura, and Maharashtra are currently using their groundwater resources at a moderate rate.</li> <li>If the current trend of increasing demand for water continues, it could lead to supply shortages, potentially causing social upheaval and disruptions.</li> </ul> <p>======</p> <h5 id="lagoons-and-backwaters">Lagoons and Backwaters</h5> <ul> <li>India has a extensive coastline with several indented sections, leading to the formation of numerous lagoons and lakes.</li> <li>Kerala, Odisha, and West Bengal are some of the states with substantial surface water resources in these lagoons and lakes.</li> <li>The water in these water bodies is typically brackish, but is utilized for activities like fishing and irrigation of paddy crops and coconut trees.</li> <li>These water bodies are primarily used for fishing and irrigating specific types of paddy crops and coconut trees, despite the brackish water.</li> <li>The states of Kerala, Odisha, and West Bengal are particularly notable for their significant surface water resources in lagoons and lakes.</li> </ul> <p>======</p> <h5 id="water-demand-and-utilisation">Water Demand and Utilisation</h5> <ul> <li>India’s economy is traditionally agricultural, with two-thirds of the population dependent on agriculture.</li> <li>Irrigation has been prioritized in Five Year Plans, with projects like Bhakra-Nangal, Hirakud, Damodar Valley, Nagarjuna Sagar, and Indira Gandhi Canal.</li> <li>Currently, water demand is dominated by irrigation needs, with agriculture accounting for 89% of surface water and 92% of groundwater utilization.</li> <li>The industrial sector uses 2% of surface water and 5% of groundwater, while the domestic sector uses 9% of surface water and a smaller percentage of groundwater.</li> <li>The agricultural sector uses the majority of water, but as the country develops, the shares of industrial and domestic sectors in water utilization are expected to increase.</li> </ul> <p>======</p> <h5 id="demand-of-water-for-irrigation">Demand of Water for Irrigation</h5> <ul> <li>Irrigation in agriculture is essential due to spatio-temporal variability in rainfall, with north-western India and the Deccan plateau being particularly deficient.</li> <li>Provision of irrigation allows for multiple cropping and higher agricultural productivity, and is necessary for crops with high water requirements, such as rice, sugarcane, and jute.</li> <li>In Punjab, Haryana, and western Uttar Pradesh, over 85% of the net sown area is under irrigation, with the majority being supplied through wells and tubewells, leading to significant groundwater depletion.</li> <li>Over-use of groundwater resources in these states has led to increased fluoride and arsenic concentrations in some areas.</li> <li>Intensive irrigation in Punjab, Haryana, and western Uttar Pradesh is leading to increased soil salinity and further groundwater depletion, which will likely have negative impacts on agriculture in these regions.</li> </ul> <p>======</p> <h5 id="emerging-water-problems">Emerging Water Problems</h5> <ul> <li>The per capita availability of water is decreasing due to population growth.</li> <li>Industrial, agricultural, and domestic effluents contaminate the available water resources.</li> <li>This pollution further reduces the availability of usable water resources.</li> <li>Water pollution is a result of various types of effluents.</li> <li>The text highlights the issue of emerging water problems due to pollution and population growth.</li> </ul> <p>======</p> <h5 id="deterioration-of-water-quality">Deterioration of Water Quality</h5> <ul> <li>Water quality is defined as the purity of water, free from foreign substances.</li> <li>Major factors that deteriorate water quality include micro-organisms, chemicals, and industrial wastes.</li> <li>Pollution of water occurs when toxic substances dissolve or suspend in water, affecting aquatic systems and sometimes seeping down to pollute groundwater.</li> <li>The Ganga and Yamuna rivers are among the most polluted in India.</li> <li>Summarization does not include finding major towns/cities on the Ganga and its tributaries and their major industries as per user instruction.</li> </ul> <p>======</p> <h5 id="water-conservation-and-management">Water Conservation and Management</h5> <ul> <li>The importance of water conservation and management is highlighted due to the declining availability of freshwater and increasing demand.</li> <li>Water availability from the sea/ocean is not considered a viable source due to the high cost of desalination. India needs to take quick steps in developing effective policies, laws, and measures for its conservation.</li> <li>It’s essential to develop water-saving technologies, prevent pollution, encourage watershed development, rainwater harvesting, water recycling and reuse, and practice conjunctive use of water.</li> <li>Fig. 4.2 illustrates the Ganga and its tributaries, along with the towns located on them, emphasizing the importance of the region’s water resources.</li> <li>Sustaining water supply in the long run requires a focus on the above-mentioned strategies.</li> </ul> <p>======</p> <h5 id="prevention-of-water-pollution">Prevention of Water Pollution</h5> <ul> <li>The quality of available water resources is degrading rapidly, with major rivers retaining better quality in upper hilly areas.</li> <li>Pollution in rivers is primarily due to organic and bacterial contamination from agricultural, domestic, and industrial effluents.</li> <li>The Yamuna, Sabarmati, Gomti, Kali, Adyar, Cooum, Vaigai, Musi, and Ganga are some of the most polluted rivers in India.</li> <li>Groundwater pollution is prevalent due to high concentrations of heavy/toxic metals, fluoride, and nitrates in various parts of the country.</li> <li>Legislative provisions such as the Water (Prevention and Control of Pollution) Act 1974, Environment Protection Act 1986, and Water Cess Act 1977 have not been effectively implemented, leading to 251 polluting industries along rivers and lakes in 1997.</li> </ul> <p>======</p> <h5 id="recycle-and-reuse-of-water">Recycle and Reuse of Water</h5> <ul> <li>Water recycling and reuse is a method to improve fresh water availability.</li> <li>Lower quality water like reclaimed wastewater can be used by industries for cooling and fire fighting, reducing water costs.</li> <li>In urban areas, water used for bathing, washing utensils, and vehicles can be reused for gardening, conserving better quality water for drinking.</li> <li>Recycling of water is currently practiced on a limited scale, but there is significant potential for water replenishment through recycling.</li> <li>It is recommended to observe water usage at home and identify ways to reuse and recycle water in various activities.</li> </ul> <p>======</p> <h5 id="watershed-management">Watershed Management</h5> <ul> <li>Watershed management is the efficient management and conservation of surface and groundwater resources, preventing runoff and promoting storage and recharge through methods like percolation tanks and recharge wells.</li> <li>It also includes conservation, regeneration, and judicious use of all natural (land, water, plants, animals) and human resources within a watershed, aiming to balance natural resources with societal needs.</li> <li>The success of watershed development largely depends on community participation, with programs like Haryali, Neeru-Meeru, and Arvary Pani Sansad promoting water conservation for drinking, irrigation, fisheries, and afforestation.</li> <li>Tamil Nadu has made water harvesting structures in houses compulsory, and while there have been successful rejuvenation stories, widespread awareness and integration of water resource management are needed for sustainable water availability.</li> <li>Watershed development projects are still in their nascent stage in many areas, with the majority requiring more time and effort to ensure long-term benefits.</li> </ul> <p>======</p> <h5 id="rainwater-harvesting">Rainwater Harvesting</h5> <ul> <li>Rainwater harvesting is a method to capture and store rainwater for various uses, including recharging groundwater aquifers. It is a low cost and eco-friendly technique to preserve water.</li> <li>Rainwater harvesting has been practiced in various methods by different communities in the country for a long time. Traditional rainwater harvesting in rural areas is done by using surface storage bodies, like lakes, ponds, irrigation tanks, etc.</li> <li>There is a wide scope to use rainwater harvesting technique to conserve precious water resource. It can be done by harvesting rainwater on rooftops and open spaces. Harvesting rainwater decreases the demand for groundwater and prevents soil erosion.</li> <li>The National Water Policy 2002 stipulates water allocation priorities in the following order: drinking water, irrigation, hydro-power, navigation, industrial and other uses. It also emphasizes on improving water utilization efficiency and promoting conservation consciousness.</li> <li>Jal Kranti Abhiyan (2015-16) is a campaign launched by the Government of India to ensure water security through per capita availability of water in the country. It aims at involving local bodies, NGOs and citizens in creating awareness regarding water conservation and management.</li> </ul> <p>======</p>