Date:22/03/2007 URL: http://www.thehindu.com/2007/03/22/stories/2007032222180500.htm

Karnataka - Bangalore

A little care can ensure enough water for all

Swathi Shivanand

Water Day today; there will be surplus water if the supply is managed properly, says expert

CHASING A MIRAGE? Trekking long distances in searing heat is inevitable for these women to get a pail of water. — Photo: K. Murali Kumar

BANGALORE: With water scarcity hitting new levels each summer in the city, adopting sustainable methods of water management becomes crucial for future growth of the city.

Coincidentally, the theme for World Water Day this year is "coping with water scarcity" and Food and Agriculture Organisation is the co-ordinating agency. One man, after two-and-a-half years of research, has come up with a sustainable water management strategy for the city, involving policies that become crucial for implementation in Greater Bangalore areas.

A.R. Shivakumar, Principal Investigator at the Karnataka State Council for Science and Technology, in his paper "Revelation in Bangalore Water Supply — A Sustainable Water Management Strategy for Emerging Greater Bangalore", has come up with a plan of action that can mitigate the impending crisis to a large extent.

Mr. Shivakumar has assessed that the Bangalore Water Supply and Sewerage Board (BWSSB) has the capacity to supply 611 million litres daily (MLD), of which Cauvery need provide only 50 per cent. Which means that the rest can be met from other sources.

About 122 MLD can be had from rainwater harvesting and recycling water each and 61 MLD can be groundwater. This proposal is especially workable and can meet further demands because the potential for exploitation of these sources is much more than required.

For example, in a year, rainwater harvesting can yield 66,424 million litres but only 44,625 million litres will be required. Similarly, 34,373 million litres of groundwater is available but only 22,313 million litres is needed. For secondary uses such as gardening, flushing and car washing, 44,625 million litres can be consumed but unfortunately, water recycled is only 25,550 million litres.

Recycling

In fact, one of the recommendations that Mr. Shivakumar makes is that Bangalore Water Supply and Sewerage Board (BWSSB) enhance its tertiary treatment capacities to at least 100 MLD. Besides, large consumers like the Defence, Railways and the Bangalore Mahanagara Palike can take to recycling, he suggests.

All the estimated 6.5 lakh properties in BMP areas can each have a sizeable rainwater sump and apartments and institutions can have bigger sumps proportionate to their terrace area. Rainwater harvesting must be made compulsory and public parks must have the systems installed.

Rrecharging

Mr. Shivakumar suggests that groundwater be recharged through trenches in storm water drains (SWD) for which it is imperative that sewage is not allowed into the SWDs. Tree-based parks must be encouraged instead of large patches of lawn as it can help in recharging water.

Groundwater extraction should be regulated and only the amount of water required by users of a particular building should be allowed, he says. For preventing groundwater contamination, use of organic manure, permitted pesticides, eco-friendly detergents and strict enforcement of effluent treatment is suggested.