Chapter 3 Water Resources
(1) 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.
(2) Give an argument in favour of multi-purpose river projects.
(a) Not suffering from water scarcity.
(b) Not suffering from water scarcity.
(c) Suffering from water scarcity.
(d) Suffering from water scarcity.
(2) Multi-purpose projects generate electricity for industries and homes. For example, in the Satluj-Beas river basin, the Bhakra-Nangal project water is being used both for hydel power production and irrigation.
Answer the following questions in about 30 words :
(1) Explain how water becomes a renewable resource.
(2) What is water scarcity and what are its main causes ?
(3) Compare the advantages and disadvantages of multi-purpose river projects.
Water becomes a renewable resource by hydrological cycle. The fresh water which is
only a small proportion of water available on earth is mainly obtained from surface run off and groundwater that is continually being renewed and recharged through the hydrological cycle. Thus, all water-precipitations, surface run off and groundwater that moves within the hydro-logical cycle ensures that water is a renewable resource.
1. Water scarcity implies water-shortage in low rainfall regions or drought prone areas. It is related to availability of bad quality of water as well. For example, in Rajasthan we see women balancing many ‘Matkas’ (earthen pots) used for collecting and storing water and travelling long distances to get water. The availability of water resources varies over space and time, mainly due to variations in seasonal and annual precipitation. Thus, it implies shortage of water in comparison to its demand in an area.
2. The main causes of scarcity of water are mentioned below :
- Increase in population : The water scarcity is an outcome of large and growing population that needs more water for domestic use as well as to produce more food. This leads to over-exploitation of water resources to expand irrigated areas and dry-season agriculture. More tubewells for irrigation leads to falling groundwater levels, adversely affecting water availability.
- Intensive industrialisation : In post independent India, there has been intensive industrialisation. More industries means need for more water and more power to run them. As such to meet the requirement, energy is produced from hydroelectric power. Thus, industriali-sation has led to more consumption of water. In India, hydroelectric power contributes 22 per cent of the total electricity produced.
- Urbanisation : Multiplying urban centers with large and dense populations and urban life-styles have not only added to water and energy requirements but have further aggravated the problem. People have their own groundwater pumping devices to meet their water needs. This leads to over-exploitation and depletion in the cities.
Bad quality of water too leads to scarcity of water. There may be sufficient water in an
area but it may be polluted by domestic and industrial wastes, chemicals, pesticides and fertilisers used in agriculture, thus, making it unsafe for human use.
- Unequal access to water among different social groups : Some time, the poor people in Jhuggi-Jhopri colonies may not get water for their use. The well-to-do people in their colonies may get water. This policy of discrimination of unequal access to water leads to scarcity of water for poor people, particularly in metropolitan Uties.
(3) Advantages and disadvantages of multi-purpose projects :
- Dams built under the multi-purpose projects help to irrigate agricultural fields.
- Multi-purpose projects help in the generation of electricity. For example the Bhakra- Nangal project is being used both for hydel power production and irrigation.
- It provides water supply for industry and domestic use.
- It helps to control floods. For example, the Hirakud project in the Mahanadi basin integrates conservation of water with flood control.
- These places have become places of recreation for the people.
- These projects are used for inland navigation.
- These projects have helped in fish breeding.
- In view of the above advantages, the multi-purpose projects were thought of as the vehicle that would lead the nation to development and progress. Jawaharlal Nehru proudly proclaimed the dams as the “temples of modern India” because it would integrate the development of agriculture and the village economy with rapid industrialization and growth of the urban economy.
(2) Disadvantages :
- It affects the natural flow of the river causing poor sediment flow and excessive sedimentation at the bottom of the reservoir resulting in rockier stream beds and poorer habitats for the rivers’ aquatic life.
- Dams fragment rivers making it difficult for aquatic fauna to migrate, especially for spawning.
- The reservoirs that are created on the floodplains submerge the existing vegetation and soil leading to its decomposition over a period of time.
- These projects lead to large-scale displacement of local communities who have to give up their land and livelihood. This in turn led to social movements like the ‘Narmada Bachao Andolan’ and ‘Tehri Dam Andolan’. Local people often had to give up their land, livelihood and their meagre access and control over resources for the greater good of the nation. The local people i.e., landless labourers do not get any benefit from such projects.
- With irrigation facilities the farmers have changed their crops to water-intensive and commercial crops. This has great ecological consequences like salinisation of the soil.
It has transformed the social landscape i.e., increased the social gap between the
richer landowners and the landless poor.
- It has led to conflicts between people wanting different uses and benefits from the same water resources as has happened in Gujarat. Where the Sabarmati basin farmers were agitated and almost caused a riot over higher priority given to water supply in urban areas, particularly during droughts.
- Multi-purpose projects have led to interstate water disputes that are becoming common with regard to sharing the costs and benefits of these projects.
Answer the following questions in about 120 words :
(1) Discuss how rainwater harvesting in semi-arid regions of Rajasthan is
(2) Describe how modern adaptations of traditional rainwater harvesting meth¬ods are being carried out to conserve and store water.
- In the semi-arid and arid regions of Rajasthan, particularly in Bikaner, Phalodi and Barmer, almost all the houses
- traditionally had underground tanks or tankas for storing drinking water.
- The tanks could be as large as a big room.
- One household in Phalodi had a tank that was 6.1 meters deep, 4.27 meters long and 2.44 meters wide.
- These tankas were part of the well developed rooftop rainwater harvesting system.
- These 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.
- The rainwater is stored in the tankas till the next rainfall.
- It is the most reliable source of drinking water when all other sources are dried up, particularly in the summers.
Rainwater called as ‘palar pani’ is considered the purest form of natural water. Not only this, many houses construct underground rooms adjoining the ‘tanka’ to beat the summer heat as it would keep the room cool.
However, the practice of rooftop rainwater harvesting is on the decline due to the perennial Rajasthan Canal which has made the availability of plenty of water in the area.
(2) Modern adaptations of traditional rainwater harvesting methods are being carried out in many parts of the country to conserve and store water as mentioned below :
- In Gendathur village in Mysore, Karnataka, nearly 200 households have installed the system of rainwater harvesting.
- Gendathur receives an annual precipitation of 1,000 mm, and with 80 per cent of collection efficiency and of about 10 fillings, every house can collect and use 50,000 liters of water annually.
- From the 20 houses, the net amount of rainwater harvested annually comes to 1,00,000 liters. Thus, the rainwater harvesting system is being carried out successfully in Gendathur which has earned the rare distinction of being rich in rainwater.
In addition to Gendathur, Tamil Nadu is the first and the only state in India which had made rooftop rainwater harvesting structure compulsory to all the houses across the state. There are legal provisions to punish the defaulters.
Thus, modern adaptations of traditional rainwater harvesting methods are being carried out to conserve and store water.
In Meghalaya, a 200-year-old system of tapping stream and spring water by using
bamboo pipes, is prevalent. About 18-20 liters of water enters the bamboo pipe system, gets transported over hundreds of meters, and finally reduces to 20-80 drops per minute at the site of the plant.