As Ulsoor Lake has been drained and the desilting process has been taken up after more than three decades, lake conservation activists have taken objection to the lakebed being desilted by only 0.6 metres, arguing that it is insufficient. 

The rejuvenation of the 106-acre lake, one of the few water bodies in Central Bengaluru, is being taken up at a total cost of ₹107 crore. 

“Ideally, there should have been a geotechnical study to determine the amount of silt sedimentation accumulated and depending on that, the extent of desilting must have been determined,” said V. Ramprasad of Friends of Lakes. 

A senior official from the Bengaluru Central City Corporation conceded that they had proposed desilting the lake by 1 metre in the Detailed Project Report (DPR), but ended up deciding to desilt only 0.6 metres due to budget constraints and the cost of transporting the excavated silt. The officer said the DPR approved by the Karnataka Tank Conservation and Development Authority proposes desilting by only 0.6 metres.

However, another officer said that the extent of desilting was not uniform and that it varied depending on the area of the lake, adding that the average was 0.6 metres, but it could be deeper in some parts. 

R. Rajagopalan, convenor, Bengaluru Coalition, a civic organisation, has lodged a complaint with the Karnataka Lokayukta over alleged irregularities in the rejuvenation of Ulsoor Lake. He said the budget constraints for extensively desilting the lake were misleading. “Almost 80% of the funds allocated for the project are being used for ornamental projects like an expanded walking track, which has encroached into the lake. This is illegal. The civic body must first prioritise restoring the primary function of the lake,” he argued. 

Mr. Ramprasad said lakes have primarily become a tool for flood mitigation, which is one of the objectives of rejuvenating and desilting the lake. “But if it is not desilted sufficiently, the water retention capacity of the lake will not be utilised fully, and this will render the whole exercise inadequate,” he argued. 

Silt being dumped in landfill

The silt being removed from the lake bed is usually considered very fertile soil, and there is a high demand for it among farmers. Many farmers had taken silt from Varthur Lake when it was desilted a few years ago. However, BCCC officials said the silt being removed from the Ulsoor Lake bed was being dumped in an empty quarry pit used as a landfill in Mittanagahalli.

“There is a lot of plastic waste in the silt. If we were to give it to farmers, the plastic would have to be removed from the silt, which would again add to the costs,” the officer said.