Rainwater harvesting yet to take off in Thiruvananthapuram

Thiruvananthapuram: The city is thirsting for water and people are taking to the streets as their sole source of water, the KWA pipe, is running dry. Case in point – Thycaud residents on Thursday led by councillor Vidya Mohan staged an agitation complaining that it was almost a month since they got adequate water.
It is at such times that one starts to think of rainwater harvesting. “About five people come daily asking about setting up rainwater harvesting units,” says Communications and Capacity Development Unit (CCDU) Director V Subhash Chandra Bose.

However, city residents are still flouting the Kerala Municipality Building Rules amended twice, in 2004 and 2014, which stipulates provisions for rainwater harvesting for new buildings.

Rainwater harvesting is mandatory for all houses, except those, which have a floor area up to 150 sq metres and plot area up to 320 sq metres (7.9 cents), as per the rules. “They show rainwater harvesting units in building plans, as building permits will not be issued otherwise. But the construction flouts the plan. But Occupancy Certificates are issued, as officials are pressurised by everyone including Councillors,” says a Corporation official.

Rainwater harvesting arrangements are not expensive. “Houses with open wells can direct rainwater using roof gutters, down pipes and a filter unit to recharge the well. The system costs around Rs 5000. In the case of rooftop rainwater harvesting systems, a 10,000 litre tank might cost Rs 40,000,” says the CCDU director.

Corporation officials say that they do not have data on the number of houses which have rainwater harvesting units. Houses in Kerala with direct recharge of open wells is 1 lakh and that of rooftop rainwater harvesting is over 2 lakhs.
That would be about 5 per cent of the 60 lakh households that Kerala is estimated to have. “Many come to us with queries, but later masons help them execute it. We are still thinking of a better way to follow up,” says Bose.

Rainwater harvesting in five cents: When people ask whether it is possible to set up a rainwater harvesting unit when there is no land, CCDU Director V Subhash Chandra Bose has a perfect example at his home. The 10,000-litre capacity tank has been constructed in his 5-cent plot at Pattom, next to a car shed.

“I could have made it fully underground. However, just so that I can show it to people, 30 per cent of it was built above ground,” he says. The water is used for non-drinking purposes. He says that in a day, if average consumption was around 500 litres, only 100 litres would be for drinking water. “Why do you need the purest water for washing your cars?” he asks.