Queen’s Road :
It looks like the monsoon has set in, bringing along wet days and the opportunity to harvest rainwater.
In November 2009, the state government made rain water harvesting compulsory for all buildings that came up after that and all those on sites bigger than 2,400 sq ft. But there’s no reason to be alarmed if you haven’t installed the facility yet — you can collect rainwater or recharge groundwater without investing too much time or money.
Catch the rain
A couple of the city’s experts say that you can save a lot of water by taking a few simple steps. Put a 500 or 1,000-litre barrel under the pipe that carries your roof water, advises S Vishwanath, founder of Rainwater Harvesting Club. Or attach a wall-mounted filter to the pipe which is called a pop-up filter, and let the water flow into your sump tank or borewell.
“The filter flushes out the first three minutes of water flow so that any dried leaves or bird droppings are washed away,” says Shivakumar. “The rest of the water is filtered by a cartridge.”
However, despite the filter, it’s essential to keep your roof clean to avoid contamination. Shivakumar recommends sweeping once a week and ‘perhaps on days when it looks like it might rain.’
“In smaller houses, since the city is filled with so many, buckets or pitchers can be placed under the pipe or space left for the roof water to come down,” he adds. And whatever little water is collected can be used.
These steps, when adopted by apartment complexes, will help save money on tanker water at least on some days of the year, he adds. “But they should stick to collecting water and using it. Don’t try to recharge the groundwater as most likely, many borewells would have dried up in such areas. The water just disappears and you don’t reap the benefits.”
Social cause
However, other households can dig out a recharge well into which you can direct all the excess rainwater, water that you don’t have space to store. “You can use a pre-cast cement ring, a minimum of 3 ft in diameter. The well should be at least 10 ft deep,” says Vishwanath. “It will take you half a day and someone will do it for you for about Rs 10,000.”
If you’re more socially inclined, for recharging the depleting groundwater table is indeed a social cause according to Shivakumar, you could even make trenches in the stormwater drain. “In open drains, it’s easy to break one of the stone slabs at the bottom, dig up a few feet and fill it with gravel,” he says.
Safe to drink
Contrary to popular belief, rainwater collected from your rooftop — when its kept clean — is even safe for drinking, both experts say. In fact, it is in Shivakumar’s eco-friendly house, whose family of four has sustained only on rainwater for 20 years now.
“We don’t have a BWSSB connection,” he says. Even the water from the washing machine — essentially soap water — is reused for toilet flushing and the kitchen sink water for the garden.
Actually, if you put in place the barrel, the filter and the recharge well, you’ve done 90 per cent of what you can about rainwater harvesting, Vishwanath says. “The challenge is to overcome the starting trouble.”
source: http://www.newindianexpress.com / The New Indian Express / Home> Cities> Bengaluru / by Express News Service / June 11th, 2015