Sewage and Puttenahalli Lake: A See Saw Relationship
by Usha Rajagopalan
As much as we trustees share a dream to see our Puttenahalli Lake thrive, we share a nightmare – of pollutants killing it. There are no industries around so we do not fear inflow of heavy metals. What has always given us the jitters is domestic waste finding their way in and smothering the life out of the lake. This is the number one killer of lakes, rivers and ponds. Filling a lake with sewage can be done in no time. One has to simply direct their waste water into the nearest storm water drain and voila, the job is done.
In February 2011, even while phase 1 of the rejuvenation was going on, we spotted sewage entering the lake from the neighbouring Lakshmi Layout and promptly brought it to the notice of the BWSSB. With no response forthcoming, we escalated it steadily and finally met the Chief Engineer a year later. As luck would have it, BWSSB happened to be laying an underground drain in the area. He directed his office to extend the drain and divert the sewage.
When his engineers came to inspect the lake premises, we urged them to lay the pipeline along the eastern side rather than replace the existing drain in the west. For, by then, we had already planted trees on either side of the pathway and didn’t want the roots to damage the pipe. The eastern side comprising an area of a little over an acre was comparatively risk free. At that time, in early 2012, there were about 40 houses built well inside, away from the pathway.
The next influx was in April 2015, even as we were planning to feed the lake with treated water from the STP of South City apartment complex in the vicinity. All approvals had been obtained and we were exuberant about seeing the lake fill with water when the owner of the coconut grove next door got all the palms cut down. The steady stream of heavily laden lorries and vehicles clearly meant a big building was coming up, a Convention Centre as it turned out. The heavy vehicles passed over an underground chamber which one day collapsed with the weight and raw sewage began to enter the lake once again. You can read the report here. We got it resolved and the lake recovered. Trouble struck again two years later.
What began as an occasional trickle of sewage in March 2017 became a regular gush which led to a massive fish kill next March. When BWSSB finally agreed to replace the UGD with a bigger pipe, they came up with another problem. The number of illegal houses had gone up to 115 and a few of these were built right above the UGD. These dwellers refused to shift temporarily elsewhere in the lake premises. We were not going to keep quiet either and continued to hound BWSSB. In the end, they bypassed these houses and laid the drain on the revetment, just a few feet above the water. The sewage stopped at last. But will it enter from another point? Can we ever relax our vigilance?
Just thinking of those days or reading our reports here and here makes us furious at the callousness of those who think that storm water drains are the conduits for their sewage and the sluggishness of the government in handling such desperate calls to protect the lake from raw sewage, a sure killer.