The main occupation of the people in our country is farming. We depend on rainwater to grow crops. It does not rain regularly throughout the year. We do not receive the same amount of rainfall in all parts of the country.
Thus we cannot depend only upon rainfall to grow our crops. We must make other arrangements to water the fields at the proper time. Irrigation is one of the important ways to do it. Canals, wells and tanks are three important means of irrigation. Today, India has one of the largest irrigation systems in the world.
The canal is the most important source of irrigation in India. Channels are dug to build canals. River-water is diverted into these canals. The canals can take river-water to the far-off fields, where there is not enough water. At some places, the river-water has to be stored. We can build a barrier of cement and steel to block the flow of river-water. This is called a dam. A huge lake is created behind the dam. The water from the lake can regulate the flow of water in the river. The water from such lakes can also be diverted to the canals for irrigation. Punjab, Haryana, Uttar Pradesh, West Bengal and Tamil Nadu have a good network of canals.
Dams also help in the production of electricity. When water from the lake behind the dam is made to fall from a high point, it is used to turn turbines which produce electricity. The dam also helps to control floods in the river. A project which helps to provide water for irrigation, produces electricity and controls floods in the river is called a multipurpose project.
Since independence, our government has built a number of multipurpose projects. Some of them are shown on the map. Find out the names of the others dams and the rivers they are built on. When it rains, some water seeps through the soil and goes deep into the ground. We can reach this underground water through wells. Where the water is not too deep, we normally use the Persian wheel or rahat to draw out this water. Deep tube wells have to be bored when the water is at a great depth. Wells and tube wells are mostly used for irrigating fields in northern and western India. Rain water is also collected in tanks and later used for irrigating the fields.
In the cities and villages, people need water for drinking, cleaning, cooking, washing and bathing. This water must be free from impurities. In cities, taps are fitted in the houses and the municipal committees supply purified and filtered water through pipelines to them. In villages too, taps have been fitted so that drinking water can be supplied. But there are villages where the people have to bring water from far-off places. The government is trying to arrange the supply of clean drinking water in these villages as well.
We must keep the water clean and store it in a proper place, protected from dust and insects. Dirty water can make us sick. We must not waste water as it is a valuable natural resource.