मराठीत वाचण्याकरिता खाली स्क्रोल करा.So far it is considered that irrigation of land using dams and canals is the best. Agriculture scientists advise Sprinkler or Drip Irrigation to save water instead of surface irrigation. This is useful where floating solids in water are negligible. Present availability of water for irrigation is much less than rainfall as most of the water flows to sea. In Maharashtra State Konkan region is the best example to understand this. Total rainfall (almost entire rainfall is during June to August) is over 3 metres per annum. However during summer even drinking water is not available to villagers. Reason specified by government departments is, reasonably levelled area is not available for storage of rain water. In most of other parts in India tall dams are constructed for storage of water. However, none of the dams is big enough to store entire rainfall in catchment area. Such dams do force people to immigrate. Almost in every case, the government doesn’t take efforts to rehabilitate these people properly and speedily. Thus there is a reason to undertake research in modifying our irrigation system.
Desired system should reduce immigration to nearly zero, store (either above ground or below ground level) entire requirement of water for over a year, cost should be low and work should be speedy. Thorough investigations and research is needed to find a new system suitable for India. I have some suggestions. Fundamental efforts should be for storing rain water for use during other seasons. Storage facility should be such that it would be economical, practical, avoid losses during storage and requiring almost zero land. Bearing this in mind I suggest the following:-
1. Dams are needed for storing water. However, storage area needs land and mostly covers forest or residential villages. Hence the height of dam should be as low as possible. There may be need to construct many more dams at regular intervals on the river. This may cost more as far as construction cost is considered. However, it may be found faster and avoiding immigration of people.
2. Canals for carrying water should be larger than presently constructed. The reason is water flow in canals would be much more during rainy season. This means land saved for storage of water would be needed for carrying water. If need arises special pumping arrangement may be provided to empty water stored in dam.
3. Canals so constructed must not be lined with concrete or any other material to stop leakage/seepage. Water seepage should be encouraged with exception of water going back to river. Water seepage from canals shall be stored underground for use when rain water is not available for irrigation.
4. Every village should have above ground/below ground level storage tank to store water needed for village for at least 1 year. This tank also may not be lined to stop seepage. We should take full advantage of storing water underground in a natural way. There are many natural water channels in the form of seasonal rivers, or small streams. These can be used to carry water to areas where rainfall is scanty or insufficient. Kolhapur in Maharashtra state (India) has developed a novel method to store water in a river (or any water channel) and at the same time ensure that the sediments are not accumulated in the river. This is modification over a Weir. A weir is provided with gates which open from bed of the river. When there is adequate water flow the sediments are carried by water.
5. Water for irrigation must not be given directly from canal. Farmers should have open wells/tube wells which shall be source of water for irrigation or any other use. Considering availability of water, crop pattern and other factors which control method of irrigation such as surface, Sprinkler or drip etc. should be adopted.
6. The government should encourage farmers to take as much water as available during rainy days and store it below ground level.
7. Pumping of water would need electricity. However, there are many more advantages like immigration of people is avoided, forest is saved from submerging in water, less construction cost, speedy results and alike.
There is an inescapable need to revise water policy of India. New policy should consider storage of rain water in every village either above ground/below ground level or free storage below ground, economical methods for collecting rain water and carrying it to other places where rain fall is scares, making maximum use of natural resources like seasonal rivers, nalha and all similar water channels, using water in the most economical way.