Archive · 6 Sep 2026
GSI Warns Hebbal Tunnel Could Threaten Lalbagh’s Ancient Rock
A very old rock sits inside Bengaluru’s Lalbagh Botanical Garden.
The rock is called Peninsular Gneiss and is more than three billion years old.
It is officially recognized as a Geological Monument.
A plan proposes building a 16.7-kilometre underground tunnel near the area.
The Geological Survey of India studied the tunnel plan.
It said construction shafts for the tunnel machines might be dug close to the rock.
The digging could cause vibrations and change pressure in the ground.
The GSI warned that this might crack the rock or make existing cracks bigger.
The Geological Survey of India warned that the proposed Hebbal tunnel could endanger Lalbagh’s three-billion-year-old Peninsular Gneiss formation.
The proposed underground tunnel would run for 16.7 kilometres in Bengaluru.
The GSI submitted its warning in a report to the Karnataka High Court.
The report said shafts for Tunnel Boring Machines may need to be dug near the ancient rock.
The GSI said vibrations and stress redistribution could create new fractures or widen existing ones.
- Who
- The Geological Survey of India warned the Karnataka High Court; actor-activist Prakash Belawadi filed the related Public Interest Litigation.
- What
- The GSI warned that the proposed Hebbal underground tunnel could risk Lalbagh’s ancient Peninsular Gneiss rock formation.
- When
- The GSI submitted its report to the court on Thursday; the article does not specify a date.
- Where
- Inside Lalbagh Botanical Garden in Bengaluru, Karnataka.
- Why
- The GSI said tunnel-construction shafts, vibrations and stress redistribution could create or enlarge fractures in the rock.
- Rock age
- More than 3 billion years old
- Rock formation
- Peninsular Gneiss
- Heritage status
- Classified as a Geological Monument
- Tunnel length
- 16.7 kilometres
- Project
- Proposed Hebbal underground tunnel
- Potential construction risk
- New fractures or widening of existing fractures
- Court case
- Public Interest Litigation filed by actor-activist Prakash Belawadi