Call to repair drainage system, rejuvenate lakes

Call to repair drainage system, rejuvenate lakes

Few people know today that until 1974, the water needs of Bangalore were met entirely by the lakes and tanks (almost a thousand at one time) that had been created over the past centuries by far-sighted people. They took advantage of the two monsoons, the SW and the NE, which provided on average 800 mm of water to the city With the population then of a mere2.3 million, piped water was supplied from only two lakes, Tippegondanahalli (TG Halli) supplied 143 million litres per day, and Hesaraghatta 22mld. 

With electricity a plenty at that time (with the erstwhile KEB advertising the advantages of All Electric Homes) bore wells were getting popular as they provided water when and where needed. When we built our house in North Bangalore District in 1974, we struck water at a depth of 30 feet (which is now nearer 600 feet)
When the Cauvery Scheme was inaugurated, with the generous river being seemingly inexhaustible, the lakes and tanks lost their importance as reservoirs of water, and to ensure that the domestic, agricultural and industrial needs of the growing population was met, four so-called stages of the Cauvery Scheme were planned and executed. The fifth stage will be completed in 2012.  

TG Halli only drinking water source
When this is done, the total quantity of water available to Karnataka will be 272 thousand million cubic feet, out of which Bangalore’s share will be 19 TMC, which works out to 1310 million litres per day. The only surviving lake today from which piped water can be drawn is TG Halli, which supplies 70 mld. Therefore, the total water available to Bangalore from the Cauvery and TG Halli by 2012 will be 1380 mld. As V Balasubramaniam, former Additional Chief Secretary has forcefully pointed out, not an additional drop of water will be available from the Cauvery because we are bound by the water sharing scheme with the southern states.
This then projects into an uncomfortable situation to say the least. During the decade from 1991 to 2001, the population of Bangalore grew by 50.7 per cent, and today’s population is estimated to be 7.2 million. There is no reason to expect the population growth rate to fall in the immediate future, and by 2020, the population would be around 11 million. To serve this populace, there will be only 1380 mld. At a conservative figure, 150 mld will be required for industries, and we have to allow for a wastage of about 35 per cent which will be 450 mld. This will leave only 780 mld for domestic use, or 70 litres per capita per day. This will be only half of the norm of 150 Ipd laid down by the WHO.

It was to draw attention to this yawning gap between supply and demand that the Bangalore Environment Trust organised a seminar on ‘How to save and restore the dying lakes of Bangalore’ a few months ago. The proceedings have been published and the important point made in the meeting was that while reviving the lakes, our drainage system will have to be simultaneously repaired and extended. We have to ensure that before the water from storm water drains and sewage pipes enters the lake, it is suitably treated by STPs. Otherwise the water in the lakes will continue to be polluted and unusable. Besides this, rain water harvesting, and recharging of ground water will have to be scientifically organised.

We have the technology to undertake the tasks mentioned above, but the administrative structure and the passion to set things right is not yet in evidence. The Lake Development Authority is a crumbling structure with its CEOs departing one after another for reasons best known to them. But today’s arrangement where the responsibility for lakes is divided between BBMP, BDA, LDA, and Forest department with water supply and sewage being the responsibility of the BWSSB is a sure recipe for failure. We need one central authority with a   " charismatic chairman who is both an administrator and a technocrat who can take charge of these multifarious responsibilities.

(The writer is an environmentalist and published author)