Citizen groups and heritage advocates confronted the Geological Survey of India (GSI) on Thursday, warning that tunnelling at Lalbagh could violate heritage laws and threaten the water table.
GSI officials said a high-level expert committee is examining the future of the rock monument, while citizen representatives maintained that the site's geological integrity is non-negotiable and urged that the proposed North-South tunnel road project bypass the garden.
Participants expressed scepticism over claims that tunnelling 60 metres below the surface would be safe.
Platform change for Rajdhani Express at KSR Bengaluru"This is not just a rock; it is a shared heritage for humanity. We do not want a situation where we are told part of it can be saved. The 1975 GSI notification and the Ancient Monuments Act should ensure a complete no-construction zone," a resident said.
Others flagged concerns over the city's shrinking green cover and fragile water table.
"Lalbagh is the lungs of this city. We cannot risk the geological integrity of this site for the sake of urban infrastructure that could be routed elsewhere," another attendee said.
The discussion also covered the demand for a UNESCO World Heritage tag for the Peninsular Gneiss.
GSI officials said high-resolution images of geo-heritage sites have been submitted to the central headquarters and presented to UNESCO teams in New Delhi, but Lalbagh has not been selected. They pointed to UNESCO's parameters, which often favour non-urban, forested sites, as a challenge.
Next steps
The Additional Director General did not share his observations from Wednesday's site visit, but said citizens' concerns would be conveyed to higher authorities.
The expert team, with members from Hyderabad, Chennai and Bengaluru, inspected the site between March 31 and April 2. They are awaiting KML files and project details from the Bangalore Metro Rail Corporation Limited (BMRCL) and Bengaluru Smart Infrastructure Limited (B-SMILE) to complete their assessment.
"We are geologists, not civil engineers. Our focus is the preservation of the monument. No one can force a premature report; we will take the time required for a thorough scientific investigation," said Vijay Vishnupant Mugal, Additional Director General (ADG) and Head of Department, GSI Southern Region.
The GSI's final report will be submitted to the Union and state governments, which will decide the future of the proposed project beneath the garden.