"Water Water every where , but even not a drop to drink ".This will be the condition of most places in the world due to the limitless and thoughtless pollution. We do not think about the day that we face this condition. Without a single moment's bothering we continue our pollution activities. Some with intension and some without knowing that they are actually polluting water.

Water is the elixir of life. Without water none of the living beings can survive. We have common experience of the plants going off drowsy when it is not watered for two days in a summer day. When we , the humans experience thirst and if water or any drink is not administered for a few hours we may become tired and finally unconscious. Animals also becomes worried when water is not taken properly.

In our daily life we use water for various purposes. It include drinking , washing  both clothes and utensils , cooking , flushing , bathing , gardening etc etc. In India the water requirement by an average family per day is as given below ( statistics is in litres per day per person ).

So it is clear that the biggest usage of water is when the toilet is flushed out. Remember we are using pure water for this which can be used for drinking purpose also. So we must think about replacing pure water for using flush by some recycled waste water.

The population growth had made man to exploit the nature indiscriminately. This exploitation had resulted in a serious water crisis all over the world. Even some surveys point out that the future wars will not be for land or administration , but for fresh and pure drinking water. It is estimated that two thirds of world's population will suffer serious water problems , if immediate action is not taken over this pollution and nature exploitation.

Water is the nectar of life.The ever increasing demand  of water for irrigation , industry as well as domestic purpose had created water crisis all over the world.Ground water being the only source we must be judicious in usage of water.In order to cater our future water needs we have to find out new methods to get water conserved. The simplest and easiest method among the conservation of water is Rain Water Harvesting.

What is Rain Water Harvesting ?

Rain Water Harvesting  is the intensional collection and storage of rainwater at suitable place for various purposes like drinking , irrigation and domestic use.Here by some artificial methods the water resulted from rain will be filtered down to earth itself. Then is that process occuring naturally. Yes occurs , but the rain got in our home or locality should be preserved as under water or ground water in our own premises or where the rain had occured. Unfortunately that will not be possible naturally.The water from a rain will flow directly to the river and from there reaches sea. Also due to urbanisation the exposed surface of nature had been cut short in area and hence percolation of rainwater had reduced. Naturally ground water resources are depleted.

Being traditionally dependent on rains to recharge ponds and lakes different civilisations innovated different methods of Rain Water Harvesting .That is the system of Rain Water Harvesting is not a new idea to Indians. It was traditionally practised earlier.Many traditional water harvesting systems like Step wells, Lakes , tanks , Bawaries etc were there in India. They were used mainly for domestic and irrigation purposes.In that days the people who use them were responsible for proper maintenance of the system as well as the limited usage of water.Rajasthan , one of the rain deficient area in India is well known for its Rain Water Harvesting methods.Public and private Rain Water Harvesting systems are present there.

What is the need of Rain Water Harvesting?

Almost all may have this doubt.This is because still we hadn't reached a situation that demand Rain Water Harvesting . When the situation opens its mouth we will have to close our mouth!!!Some reasons to put forward Rain Water Harvesting  or to practice Rain Water Harvesting  is listed below. Remember these are only some of the reasons.

1. To conserve surface run off water during rainy season especially in mansoon.
2. To enhance availability of ground water
3. To rise or improve the aquifers water quality.
4. To rise water levels in wells and bore wells that dry up in summer season.
5. To reduce over exploitation of ground water.
6. To reduce soil erosion
7. To improve the vegetation

As already told Rain Water Harvesting is a method of cheneling the rain water into ground and recharging the ground water resources in different from the current practice of flowing to sea.Rain Water Harvesting can be carried out by two methods.One method is harvesting the surface runoff.Here the run off water is caught and aquifers are recharged.For this appropriate method can be used.Second method of Rain Water Harvesting is roof top harvesting. Here all the water that is falling over roof is collected through suitable pipes to a tank or any such storage methods. This is less expensive , but effective and hence commonly practiced.A third method that widely practiced now is Rain Pit method.All the rain water can be directed to a pit and either allowed to ground there or directed to a tank after proper filtration.In Kerala all new houses should have these rain pits to get approval from respective authorities.

What are the benefits of Rain Water Harvesting?

When we introduce a method its benefits are also to be considered. The awareness about the benefits of Rain Water Harvesting will lead more to adopt these methods.Some of them are listed below.

1. The level of ground water will rise.
2. Overflow of drainages and flooding of roads will be reduced.
3. The water scarcity in areas having limited water resources will be solved.
4. Soil erosion will be controlled
5. Drought can be controlled.

The harvested water is used by all directly.So the water caught should be free from pollutants.Hence we must take some pre cautionary measures before harvesting the rain water.Some of the measures are given below.

1. If the roof top method is followed for Rain Water Harvesting , the roof should be clean.It should be free from dust, plants , other dirts , birds and animals excreta, poisons and pesticides.
2. The first rain of season will have all dirts of atmosphere. So it should be flushed away.Sufficient provision for this should be there in our Rain Water Harvesting system.
3. Painted roof is not good since paints may have toxic ingradients.
4. Before recharging the ground water with the harvested water proper arrangement for filtration should be done.
5. The filter should be periodically checked and should be cleaned before every rain season.Before mansoon start all the system should be cleaned well.
6. Never use polluted water to recharge the ground water.

What are the threats?

Some threats exist over Rain Water Harvesting. Urbanisation is one of the major threat.Chennai gets a rainfall above the country's average rain fall. But due to urbanisation there is no way to store it in earth. So only 5 % of rain water is collected. 95 % of rain got is flew to sea. Also some persons has the opinion that the storage of rain water over large area may affect stream flows. Then it will reduce transport of nutrients and sediments of soil. Consequently the habitat may be destroyed. That is the hydrological cycle is disturbed.The only solution for such threats is choosing water sheds of suitable size and putting forward a water budget.

Conclusion

Our water management system must be reformed. Also the traditional systems should be revived. The present status should be assessed by scientific methods using new technologies. People should initiate these process and they should come forward actively to participate in such activities.Remember the words ' high quality of water , in the right quantity at the right place at the right time is essential to health , recreation and economic growth.So it is the time to wake up."Better late, than never"