Often touted as a success story of lake rejuvenation in the city, Puttenahalli Lake at J.P. Nagar has been in the news in the recent past more owing to threats to its existence. The latest in the list is of alarmed residents and caretakers noticing the formation of “pits” in the lake filled with dark coloured water.
It all started when the Bruhat Bengaluru Mahanagara Palike (BBMP) started cleaning the lake recently, said trustees of the Puttenahalli Neighbourhood Lake Improvement Trust (PNLIT). “After draining the lake, they began to remove the contaminated soil from the surface in some places and further below at others. A fortnight ago, these pits filled with black water and at other places, damp patches formed where weeds began to grow. The underground water was getting exposed by the digging we thought, but the patches became pools which grew in number and size,” said one of the trusties.
According to PNLIT, on February 3, the staff at the lake reported that water was entering the wetland through one of the inlet pipes which discharged surface run off from an apartment complex, which turned out to be false. Attention was turned towards the UGD installed by the BWSSB last year.
“The ward office sent a contractor to locate the source and plug it. By then, there was some seepage from below the inlet pipes as well. He suggested that we block the pipe with sandbags. The back flow would indicate possible source which could be repaired. The sandbags remained in place and dry though the seepage from below the pipes increased as did the water level in the lake. In just four days, by February 7, many of the pools had not only grown but, they and the trenches dug by the excavators had vile, floating mass which was visible from a distance. We knew only too well that it was sewage once again,” the PNLIT trustees said.
Not the first time
They pointed out that this was not the first time that sewage had threatened the lake, with what started in 2017 as an occasional trickle of sewage from the UGD at Nataraja Layout becoming a regular feature, even leading to a massive fish-kill in March 2018. The BWSSB started replacing the existing UGD with a bigger one in August 2019, but that has not been free from problems, with challenges from illegal houses on one side and sewage on the other.
When contacted, BWSSB officials admitted that there was a blockage in the underground drain. “It will be repaired soon,” said the official.
“From 2010, working closely with the BBMP, residents from the neighbourhood and CSR partners toiled to bring a dry lake back to life. We overcame several obstacles on the way but 11 years later, the biggest two still remain — encroachment and sewage. If this situation continues, we will soon have to say, ‘Once there was a tank called Puttenahalli Puttakere’,” the trustees said.
