Water is a precious resource. Water supply is a major factor considered by anyone who plans to buy/build a home. According to the WHO, water scarcity already affects forty percent of the world’s population. With the governments not being able to meet the growing demand, the dependence on ground water has increased enormously. Most of today’s apartments and individual residences in urban areas draw water entirely from the ground. But with the continuous exploitation and no subsequent replenishment, for how long will the groundwater supply last?

Don’t panic! There are ways to ensure your home gets an uninterrupted supply of groundwater. Rainwater can be effectively used to recharge the groundwater table and replenish your water resources. Traditionally, rainwater harvesting has been practiced in arid and semi-arid regions to replenish ground water levels. The technique is simple and can be adopted at any individual residence or apartment complex. Apart from augmenting the urban water supply system, the soil properties can also be improved by implementing rainwater harvesting. An increased moisture level in the soil ensures the stability of structures and also boosts urban greenery. At a larger level, rain water harvesting is also found to mitigate flooding.

The methodology involves collecting the entire rainwater from the roof top and letting it flow into a recharge pit without being drained away from the building. It is easier to install the plumbing fixtures and dig the recharge pit during the constructing stage itself rather than taking it up separately. Proper care should be taken to ensure that only the rain water flows into the recharge pit and the waste water from the dwellings is diverted into the drainage. For this purpose, separate pipes should be installed to carry the rain water and the waste water.

The recharge pit should also be constructed carefully under the supervision of an expert. The rain water may be contaminated and it may also lead to the contamination of groundwater if it is not filtered. A sand filter should be installed at the bottom of the recharge pit to purify the rain water before it actually joins the groundwater. The pit and the filter should be so planned that the water percolates instantly without much stagnation period. The pit should be ventilated to prevent bad odours. It should be covered with light-weight cement concrete covers so that it can be inspected from time to time. Any filth that has accumulated at the bottom should be cleared during the inspection. Bleaching powder should be sprinkled in the pit periodically during the rainy season.

Apart from being easy to install and maintain, the system is light on your pocket too. In fact the installation costs can be recovered within a few years. A typical rain water harvesting system for an apartment complex would cost around Rs.80000. The savings would be to the tune of Rs.7000/100sq.mts./year in the form of reduced expenditure on municipal water. The owners of all the units in an apartment complex, as a group, should insist on the builder to construct the rainwater harvesting system. Play your part in environmental conservation and ensure an unhindered water supply for years to come!

For advise on constructing a rainwater harvesting system, mail to: chandrasekhar.yadavilli@yahoo.co.in or call 9885650480.