Puttenahalli lake gets polluted by sewage due to incomplete storm water drain built by BBMP

Bengaluru: Nearly 10 years of work that transformed Yelahanka's Puttenahalli lake into a bird conservation reserve has been washed away in the last five days as thousands of litres of sewage has flowed into the lake, which enjoys protection under the stringent provisions of the Wildlife (Protection) Act.

The latest development is the result of an incomplete storm water drain (SWD) built by the Bruhat Bengaluru Mahanagara Palike (BBMP) without taking necessary clearances from the Forest Department.

The SWD was planned to carry the sewage and stormwater from Attur and Anantpur neighbourhoods in the western and northern parts of the lake to the sewage treatment plant (STP) on the eastern side of the Doddaballapura Road.

However, the BBMP took up the construction work without taking the wildlife clearance, which is applicable to the bird conservation reserve.

As a result, the SWD which brought sewage from hundreds of households stopped at the lake boundary, near the gazebo.

K S Sangunni, a retired IISc professor who along with a group of individuals worked since 2009 to save the lake, noted that letting sewage into the lake was a violation of rules and Karnataka High Court order but no officials were held accountable.

"In response to our petition (WP 7319 of 2020), the Karnataka High Court has given specific instructions to authorities to prevent the seepage of sewage water into the reserve. What we see now is a total disregard for the order," said Sangunni, who is also the Chairman of the Yelahanka Puttenahalli Lake and Bird Conservation Trust (YPLBCT).

Apart from the work of volunteers mobilised by the trust, the government has spent crores of rupees to clean the lake, which is now receiving truckloads of sewage mixed with solid waste, including plastic, along with hyacinth on a regular basis.

BBMP Chief Engineer (SWD) B S Prahlad said that he will inspect the lake on Saturday. "Pipeline work will start in two days," he said, adding that he will inspect the situation on Saturday afternoon.

The pipeline work, activists, said was being taken up in blatant violation of forest and wildlife rules.

"This is a fait accompli situation, forcing the Forest Department to issue clearances. They have built an STP on one said and half of the SWD on the other. Now that the sewage has already started entering the lake, they want to take the sewage in an underground drainage pipe through the lake," an official told DH.

As per the documents available with DH, the BBMP woke up to the problem nearly two years after taking up the SWD work.

In a letter dated May 9, 2024, the BBMP zonal commissioner sought permission from the Forest Department to take the sewage through the lake.

However, on May 15, the Forest Department pointed to the government notification of 2017 declaring the area a conservation reserve.

"Puttenahalli Lake Bird Conservation Reserve is a protected area. Any development work in the area needs to get clearances from the State Board for Wildlife," Bengaluru Urban Deputy Conservator of Forests N Ravindra Kumar said.

To a question, Kumar said that the department had not given clearance.

"The matter has been taken up at higher authorities in the government. A decision will be taken to resolve the issue soon," he said.

Researchers have documented about 150 species of birds in the lake and noted that any pollution of the lake threatens the entire biodiversity in and around it.