Water Resources PDF

You already know that three-fourth of the WATER SCARCITY AND THE NEED FOR WATER earth’s surface is covered with water, but only CONSERVATION AND MANAGEMENT a small proportion of it accounts for freshwater that can be put to use. This Given the abundance and renewability of fre...

You already know that three-fourth of the WATER SCARCITY AND THE NEED FOR WATER earth’s surface is covered with water, but only CONSERVATION AND MANAGEMENT a small proportion of it accounts for freshwater that can be put to use. This Given the abundance and renewability of freshwater is mainly obtained from surface water, it is difficult to imagine that we may run off and ground water that is continually suffer from water scarcity. The moment we being renewed and recharged through the speak of water shortages, we immediately hydrological cycle. All water moves within the associate it with regions having low rainfall hydrological cycle ensuring that water is a or those that are drought prone. We renewable resource. instantaneously visualise the deserts of You might wonder that if three-fourth of Rajasthan and women balancing many the world is covered with water and water is ‘matkas’ (earthen pots) used for collecting a renewable resource, then how is it that and storing water and travelling long countries and regions around the globe suffer distances to get water. True, the availability from water scarcity? Why is it predicted that of water resources varies over space and time, by 2025, nearly two billion people will live in mainly due to the variations in seasonal and absolute water scarcity? annual precipitation, but water scarcity in Reprint 2024-25 most cases is caused by over-exploitation, consequent greater demands for water, and excessive use and unequal access to water unequal access to it. A large population among different social groups. requires more water not only for domestic Where is then water scarcity likely to use but also to produce more food. Hence, to occur? As you have read in the hydrological facilitate higher food-grain production, water cycle, freshwater can be obtained directly resources are being over-exploited to expand from precipitation, surface run off and irrigated areas for dry-season agriculture. groundwater. Irrigated agriculture is the largest consumer Is it possible that an area or region may of water. Now it is needed to revolutionise the have ample water resources but is still facing agriculture through developing drought water scarcity? Many of our cities are such resistant crops and dry farming techniques. examples. Thus, water scarcity may be an You may have seen in many television outcome of large and growing population and advertisements that most farmers have their Water, Water Everywhere, Not a Drop to Drink Drink:: After a heavy downpour, a boy collects drinking water in Kolkata. Life in the city and its adjacent districts was paralysed as incessant overnight rain, meaning a record 180 mm, flooded vast area and disruted traffic. A Kashmiri earthquake survivor carries water in the snow in a devastated village. Fig. 3.1: Water Scarcity 20 CONTEMPORARY INDIA – II Reprint 2024-25 own wells and tube-wells in their farms for available to meet the needs of the people, but, irrigation to increase their produce. But have the area still suffers from water scarcity. This you ever wondered what this could result in? scarcity may be due to bad quality of water. That it may lead to falling groundwater levels, Lately, there has been a growing concern that adversely affecting water availability and food even if there is ample water to meet the needs security of the people. of the people, much of it may be polluted by Post-independent India witnessed domestic and industrial wastes, chemicals, intensive industrialisation and urbanisation, pesticides and fertilisers used in agriculture, creating vast opportunities for us. Today, large thus, making it hazardous for human use. industrial houses are as commonplace as the Government of India has accorded highest industrial units of many MNCs (Multinational priority to improve the quality of life and Corporations). The ever-increasing number of enhance ease of living of people especially those industries has made matters worse by exerting living in rual areas by announcing the Jal pressure on existing freshwater resources. Jeevan Mission (JJM). The Goal of JJM is to Industries, apart from being heavy users of enable every rural household get assured water, also require power to run them. Much supply of potable piped water at a service level of this energy comes from hydroelectric power. of 55 litres per capita per day regularly on Moreover, multiplying urban centres with long-term basis by ensuring functionality of large and dense populations and urban the tap water connections. (Source: Economic lifestyles have not only added to water and Survey 2020–21, p.357) energy requirements but have further You may have already realised that the need aggravated the problem. If you look into the of the hour is to conserve and manage our housing societies or colonies in the cities, you water resources, to safeguard ourselves from would find that most of these have their own health hazards, to ensure food security, groundwater pumping devices to meet their continuation of our livelihoods and productive water needs. Not surprisingly, we find that activities and also to prevent degradation of our fragile water resources are being over- natural ecosystems. Over exploitation and exploited and have caused their depletion in mismanagement of water resources will several of these cities. impoverish this resource and cause ecological crisis that may have profound impact on our lives. Atal Bhujal Yojana (Atal Jal) is being implemented in 8220 water stressed Gram Panchayats of 229 administrative blocks/ From your everyday experiences, write a short talukas in 80 districts of seven states, viz. proposal on how you can conserve water. Gujarat, Haryana, Karnataka, Madhya Pradesh, Maharashtra, Rajasthan, and MULTI- PURPOSE RIVER P ROJECTS AND Uttar Pradesh. The selected States account INTEGRATED WATER RESOURCES MANAGEMENT for about 37 per cent of the total number of water— stressed (over-exploited, critical But, how do we conserve and manage water? and semi-critical) blocks in India. One of Archaeological and historical records show the key aspects of Atal Jal is to bring in that from ancient times we have been behavioural changes in the community, constructing sophisticated hydraulic from the prevailing attitude of structures like dams built of stone rubble, consumption to conservation and smart reservoirs or lakes, embankments and canals water management. for irrigation. Not surprisingly, we have continued this tradition in modern India by Source: Annual Report, Ministry of Jal Shakti, building dams in most of our river basins. Government of India 2022–23 So far we have focused on the quantitative Hydraulic Structures in Ancient India aspects of water scarcity. Now, let us consider In the first century B.C., Sringaverapura another situation where water is sufficiently near Allahabad had sophisticated water WATER RESOURCES 21 Reprint 2024-25  harvesting system channelling the flood Multi-purpose projects, launched after water of the river Ganga. Independence with their integrated water During the time of Chandragupta Maurya, resources management approach, were thought dams, lakes and irrigation systems were of as the vehicle that would lead the nation to extensively built. development and progress, overcoming the Evidences of sophisticated irrigation works have also been found in Kalinga, A dam is a barrier across flowing water that (Odisha), Nagarjunakonda (Andhra obstructs, directs or retards the flow, often Pradesh), Bennur (Karnataka), Kolhapur creating a reservoir, lake or impoundment. (Maharashtra), etc. “Dam” refers to the reservoir rather than the structure. Most dams have a section called a In the 11th Century, Bhopal Lake, one of the spillway or weir over which or through which largest artificial lakes of its time was built. it is intended that water will flow either In the 14th Century, the tank in Hauz Khas, intermittently or continuously. Dams are Delhi was constructed by Iltutmish for classified according to structure, intended supplying water to Siri Fort area. purpose or height. Based on structure and Source: Dying Wisdom, CSE, 1997. the materials used, dams are classified as timber dams, embankment dams or masonry dams, with several subtypes. According to the height, dams can be categorised as large dams and major dams or alternatively as low dams, medium height dams and high dams. handicap of its colonial past. Jawaharlal Nehru proudly proclaimed the dams as the ‘temples of modern India’; the reason being that it would integrate development of agriculture and the village economy with rapid industrialisation and growth of the urban economy. Fig. 3.2: Hirakud Dam Find out more about any one traditional What are dams and how do they help us method of building dams and irrigation works. in conserving and managing water? Dams were traditionally built to impound rivers and rainwater that could be used later to irrigate We have sown the crops in Asar agricultural fields. Today, dams are built not We will bring Bhadu in Bhadra just for irrigation but for electricity generation, water supply for domestic and industrial Floods have swollen the Damodar uses, flood control, recreation, inland The sailing boats cannot sail navigation and fish breeding. Hence, dams are Oh! Damodar, we fall at your feet now referred to as multi-purpose projects where the many uses of the impounded water Reduce the floods a little are integrated with one another. For example, Bhadu will come a year later in the Sutluj-Beas river basin, the Bhakra – Nangal project water is being used both for Let the boats sail on your surface hydel power production and irrigation. (This popular Bhadu song in the Damodar valley Similarly, the Hirakud project in the region narrates the troubles faced by people Mahanadi basin integrates conservation of owing to the flooding of Damodar river known as the river of sorrow.) water with flood control. 22 CONTEMPORARY INDIA – II Reprint 2024-25  In recent years, multi-purpose projects and large dams have come under great Pradhan Mantri Krishi Sinchaee Yojana scrutiny and opposition for a variety of Some of the broad objectives of this reasons. Regulating and damming of rivers programme are to enhance the physical affect their natural flow causing poor sediment access of water on the farm and expand flow and excessive sedimentation at the bottom cultivable area under assured irrigation (har of the reservoir, resulting in rockier stream khet ko pani), improve on-farm water use beds and poorer habitats for the rivers’ aquatic efficiency to reduce wastage and increase life. Dams also fragment rivers making it availability both in duration and extent, difficult for aquatic fauna to migrate, especially irrigation and other water saving for spawning. The reservoirs that are created technologies (per drop more crop) and on the floodplains also submerge the existing introduce sustainable water conservation vegetation and soil leading to its practices, etc. decomposition over a period of time. Do you know that the Krishna-Godavari Sardar Sarovar Dam has been built over dispute is due to the objections raised by the Narmada River in Gujarat. This is one Karnataka and Andhra Pradesh of the largest water resource projects of governments? It is regarding the diversion India covering four states—Maharashtra, of more water at Koyna by the Maharashtra government for a multipurpose project. This Madhya Pradesh, Gujarat and Rajasthan. would reduce downstream flow in their The Sardar Sarovar project would meet the states with adverse consequences for requirement of water in drought-prone and agriculture and industry. desert areas. Sardar Sarovar Project will provide irrigation facilities to 18.45 lakh hectare of land, covering 3112 villages in Make a list of inter-state water disputes. 15 districts of Gujarat. It will also irrigate 2,46,000 hectare of land in the strategic Ironically, the dams that were constructed desert districts of Barmer and Jalore in to control floods have triggered floods due to Rajasthan and 37,500 hectare in the tribal sedimentation in the reservoir. Moreover, the hilly tract of Maharashtra through lift. big dams have mostly been unsuccessful in About 75 per cent of the command area in controlling floods at the time of excessive Gujarat is drought prone while entire rainfall. command in Rajasthan is drought prone. Assured water supply will soon make this area drought proof. Collect information about floods occurred in Source: Sardar Sarovar Narmada Nigam Ltd. different parts of the country due to heavy https://www.sardarsarovardam.org/ rainfall in recent times. Irrigation has also changed the cropping These floods have not only devastated life pattern of many regions with farmers shifting and property but also caused extensive soil to water intensive and commercial crops. This has great ecological consequences like erosion. Sedimentation also meant that the flood salinisation of the soil. Pradhan Mantri Krishi plains were deprived of silt, a natural fertiliser, Sinchaee Yojana has been started which further adding on to the problem of land ensures access to some means to protective degradation. It was also observed that the multi- irrigation for all agricultural farms in the purpose projects induced earthquakes, caused country, thus bringing much desired rural water-borne diseases and pests and pollution prosperity. resulting from excessive use of water. WATER RESOURCES 23 Reprint 2024-25  India: Major Rivers and Dams 24 CONTEMPORARY INDIA – II Reprint 2024-25 R AINWATER H ARVESTING practised to store drinking water, Many thought that given the disadvantages particularly in Rajasthan. In the flood plains and rising resistance against the multi- of Bengal, people developed inundation purpose projects, water harvesting system channels to irrigate their fields. In arid and was a viable alternative, both socio- semi-arid regions, agricultural fields were economically and environmentally. In converted into rain fed storage structures ancient India, along with the sophisticated that allowed the water to stand and moisten hydraulic structures, there existed an the soil like the ‘khadins’ in Jaisalmer and extraordinary tradition of water-harvesting ‘Johads’ in other parts of Rajasthan. system. People had in-depth knowledge of In the semi-arid and arid regions of rainfall regimes and soil types and developed Rajasthan, particularly in Bikaner, Phalodi wide ranging techniques to harvest and Barmer, almost all the houses rainwater, groundwater, river water and flood traditionally had underground tanks or water in keeping with the local ecological tankas for storing drinking water. The tanks conditions and their water needs. In hill and could be as large as a big room; one mountainous regions, people built diversion household in Phalodi had a tank that was channels like the ‘guls’ or ‘kuls’ of the 6.1 metres deep, 4.27 metres long and 2.44 Western Himalayas for agriculture. ‘Rooftop metres wide. The tankas were part of the well- rainwater harvesting’ was commonly developed rooftop rainwater harvesting Collect information about flood prone areas of the country WATER RESOURCES 25 Reprint 2024-25 system and were built inside the main house or the courtyard. They were connected to the sloping roofs of the houses through a pipe. Rain falling on the rooftops would travel down the pipe and was stored in these underground ‘tankas’. The first spell of rain was usually not collected as this would clean the roofs and the pipes. The rainwater from the subsequent showers was then collected. Fig. 3.4 (a) Recharge through Hand Pump The rainwater can be stored in the tankas till the next rainfall making it an extremely reliable source of drinking water when all other sources are dried up, particularly in the summers. Rainwater, or palar pani pani, as commonly referred to in these parts, is considered the purest form of natural water. Many houses constructed underground rooms adjoining the ‘tanka’ to beat the summer heat as it would keep the (b) Recharge through Abandoned Dugwell Rooftop rainwater is collected using a PVC pipe Filtered using sand and bricks Underground pipe takes water to sump for immediate usage A kul leads to a circular village tank, as the above Excess water from the sump is taken to the well in the Kaza village, from which water is released Water from the well recharges the underground as and when required. Take water from the well (later) Fig 3.5: Traditional method of rainwater Fig 3.3: Rooftop Rainwater Harvesting harvesting 26 CONTEMPORARY INDIA – II Reprint 2024-25  adapted here. Gendathur receives an annual precipitation of 1,000 mm, and with 80 per cent of collection efficiency and of about 10 Rooftop rainwater harvesting is the fillings, every house can collect and use about most common practice in Shillong, 50,000 litres of water annually. From the 200 Meghalaya. It is interesting because Cherapunjee and Mawsynram situated houses, the net amount of rainwater harvested at a distance of 55 km. from Shillong annually amounts to 1,00,000 litres. receive the highest rainfall in the world, yet the state capital Shillong faces acute shortage of water. Nearly every household in the city has a rooftop rainwater harvesting structure. Nearly 15-25 per cent of the total water requirement of the household comes from rooftop water harvesting. Find out other rainwater harvesting systems existing in and around your locality. Rooftop harvesting was common across the towns and villages of the Thar. Rainwater that falls on room cool. the sloping roofs of houses is taken through a Today, in western Rajasthan, sadly the pipe into an underground tanka (circular holes in practice of rooftop rainwater harvesting is on the ground). built in the main house or in the the decline as plenty of water is available due courtyard. The picture above shows water being to the perennial Indira Gandhi Canal, though taken from a neighbour’s roof through a long pipe. some houses still maintain the tankas since Here the neighbour’s rooftop has been used for they do not like the taste of tap water. collection of rainwater. The picture shows a hole Fortunately, in many parts of rural and urban through which rainwater flows down into an India, rooftop rainwater harvesting is being underground tanka. successfully adapted to store and conserve water. In Gendathur, a remote backward Fig. 3.6 village in Mysuru, Karnataka, villagers have installed, in their household’s rooftop, rainwater harvesting system to meet their water needs. Nearly 200 households have Tamil Nadu is the first state in India installed this system and the village has earned which has made rooftop rainwater the rare distinction of being rich in rainwater. harvesting structure compulsory to all the houses across the state. There are See Fig. 3.6 for a better understanding of the legal provisions to punish the defaulters. rooftop rainwater harvesting system which is WATER RESOURCES 27 Reprint 2024-25  BAMBOO DRIP IRRIGATION SYSTEM In Meghalaya, a 200-year-old system of tapping stream and spring water by using bamboo pipes, is prevalent. About 18-20 litres of water enters the bamboo pipe system, gets transported over hundreds of metres, and finally reduces to 20-80 drops per minute at the site of the plant. Picture 1: Bamboo pipes are used to divert perennial springs on the hilltops to the lower reaches by gravity. Picture 2 and 3: The channel sections, made of bamboo, divert Picture 4: If the pipes pass a road, water to the plant site where it is distributed into branches, again they are taken high above the land. made and laid out with different forms of bamboo pipes. The flow of water into the pipes is controlled by manipulating the pipe positions. Picture 5 and 6 Reduced channel sections and diversion units are used at the last stage of water application. The last channel section enables water to be dropped near the roots of the plant. Fig 3.7 1. Collect information on how industries are polluting our water resources. 2. Enact with your classmates a scene of water dispute in your locality. 28 CONTEMPORARY INDIA – II Reprint 2024-25  EXERCISES EXERCISES EXERCISES EXERCISES EXERCISES 1. Multiple choice questions. (i) Based on the information given below classify each of the situations as ‘suffering from water scarcity’ or ‘not suffering from water scarcity’. (a) Region with high annual rainfall. (b) Region having high annual rainfall and large population. (c) Region having high annual rainfall but water is highly polluted. (d) Region having low rainfall and low population. (ii) Which one of the following statements is not an argument in favour of multi- purpose river projects? (a) Multi-purpose projects bring water to those areas which suffer from water scarcity. (b) Multi-purpose projects by regulating water flow helps to control floods. (c) Multi-purpose projects lead to large scale displacements and loss of livelihood. (d) Multi-purpose projects generate electricity for our industries and our homes. (iii) Here are some false statements. Identify the mistakes and rewrite them correctly. (a) Multiplying urban centres with large and dense populations and urban lifestyles have helped in proper utilisation of water resources. (b) Regulating and damming of rivers does not affect the river’s natural flow and its sediment flow. (c) Today in Rajasthan, the practice of rooftop rainwater water harvesting has gained popularity despite high water availability due to the Indira Gandhi Canal. 2. Answer the following questions in about 30 words. (i) Explain how water becomes a renewable resource. (ii) What is water scarcity and what are its main causes? (iii) Compare the advantages and disadvantages of multi-purpose river projects. 3. Answer the following questions in about 120 words. (i) Discuss how rainwater harvesting in semi-arid regions of Rajasthan is carried out. (ii) Describe how modern adaptations of traditional rainwater harvesting methods are being carried out to conserve and store water. WATER RESOURCES 29 Reprint 2024-25