Unless we speed up our efforts towards water conservation and judicious consumption, the problem is bound to increase.
It is good to see rain water being saved and used in urban areas on a wider scale nowadays and the resistance towards its storage reducing in the rural areas. Also, in many urban areas, rainwater harvesting is compulsory. However, this simple solution to the water crisis does not appear to have kept pace with the increasing crisis. As such unless we speed up our efforts towards water conservation and judicious consumption, the problem is bound to increase.
Among the basic causes, many city residents are apprehensive and hesitate to use it for daily needs like cooking or bathing, despite all that has been covered in the media about water harvesting as a larger proposal.
Many people collect the raw water from roof tops and let it percolate within their site. Some store the treated water in a sump for gardening, car wash and such allied purposes. Ideally we should be collecting the filtered water in a sump, pump it up to the terrace water tank otherwise done for public water supply and use it for all building and living needs. Only then we are saving the rain water to supplement daily needs. The rain water is perfectly suited for such total use.
There are a few systems to filter the water such as pop-up filters fitted within the pipes; gravel, sand and charcoal beds; and cloth filters. Let the water be filtered by the chosen system and flow into the storage sump which can be placed next to the public water sump.
Many people have installed two sets of pumps and pipes, spending much money. A single mono-block pump with single delivery pipe to the overhead tank is adequate. The pump can easily be fitted within the setback area.
There can be two suction pipes with gate valves, one fitted to public water and the other to the rain water tank. To pump up water from public supply, we need to open the valve of that sump and keep the rain water pipe closed.
When it rains and water collects, open the rain sump valve and close the public supply sump valve. It is important to keep pumping up the rain water whenever it fills the sump to maximise the benefits of harvesting.
Considering that the rain water is free, we can construct it to any volume as our funding may permit, but it is safer to maintain a minimum of 6,000 litres.
In cities with tanker water supply that can be ordered by phone, the tankers come with 6,000 litres and they would fill only one sump tank. In case of grey water tanks, they need not be placed close to the rain sumps, since no pump or pipes can be shared between the two.
It is fair on people to feel that managing both public and rain water is a difficult logistics, but if we realise how simple it is, it is our duty to manage it.