The fresh water that can be used is obtained from surface run off and ground water that is constantly renewed. The total renewable water resources of India have been estimated to be about 1897 sq kms per annum, but even then there is scarcity of water.
Main Reasons why we need to conserve water
1. Greater demands for water due to growing population, leads to falling ground water levels.
2. The rainfall is seasonal, unreliable and erratic and the farmers cannot fully depend on it for a successful harvest.
3. The evergrowing industries not only take up a lot of water but also pollute it as well.
4. Hydro-electric power also requires water for its production
Due to these reasons it is very essential that we conserve water and manage our water resources to ensure a safe future and prevent degradation of our natural ecosystems.
Rain Water Harvesting and its importance
The concept of Rain Water Harvesting has been in existence from ancient times in India, when people developed various techniques to harvest rain water, river water, flood water and ground water, according to their requirements.
Different ways of Storing Rainwater
1. Kuls or Guls: People in western Himalayas build diversion channels to provide water to the fields in the hilly regions.
2. Johads, khadins were used to store rainwater. These moistened the soil and the stored rain water was conserved for future use. These were common in Rajasthan (Alwar, Jaisalmer and Bikaner).
3. Tanks or ‘Tankas’: This consisted of a very large tank generally underground, connected to the roof from where the water travelled through a pipe. This was considered the purest form of natural water. These kept the house cool and were common in the arid and semi-arid regions of Rajasthan.
4. Bamboo Drip System: In this system rainwater was collected through bamboo pipes which transported water over hundreds of metres and then collected and distributed to the roots of the plants. This system still prevails in Meghalaya and other North-Eastern states.