Bangalore's explosive growth has come at an environmental cost , storm water drains have been encroached upon, lake catchment areas have been built over, and natural drainage paths blocked. The result: flooding in areas that were never historically flood-prone. Before buying property in Bangalore, checking flood risk is now a necessary step.
Why Flood Risk is a Legal and Financial Issue
Property in flood-prone areas faces multiple problems beyond the obvious inconvenience of flooding:
- Buildings constructed in lake buffer zones (within 75 metres of a lake) are illegal under NGT orders and face demolition risk
- Properties built on Storm Water Drain (SWD) alignments are encroachments and subject to BBMP demolition notices
- Banks are increasingly refusing to fund home loans in flood-affected zones
- Insurance claims for flood damage are disputed if the property is itself in an illegally encroached zone
- Resale values are significantly depressed for flood-affected properties
Lake Buffer Zone Rules in Bangalore
The National Green Tribunal (NGT) has mandated:
- 75-metre no-construction zone around lakes (from the Full Tank Level boundary)
- 30-metre no-construction zone along Storm Water Drains
Any building within these zones is technically illegal, regardless of whether it has received BBMP approvals (approvals for such buildings were given in error and have been challenged in court).
How to Check If a Property is in a Flood/Lake Zone
1. BBMP GIS Portal: BBMP's Geographic Information System (GIS) maps show the locations of lakes, storm water drains, and their buffer zones. You can overlay the property address to check proximity to water bodies.
2. Survey of India Toposheet: The original land survey toposheet shows natural drainage channels and water bodies. Compare with current development to identify encroachments.
3. Karnataka State Pollution Control Board (KSPCB) Lake Maps: KSPCB maintains maps of lakes and their designated boundaries. Available on request.
4. BWSSB Drainage Maps: The Bangalore Water Supply and Sewerage Board has drainage network maps that show SWD alignments.
5. Karnataka High Court / NGT Orders: Several lakes have specific High Court orders governing their buffer zones. Check for any court orders applicable to lakes near the property.
Areas of Bangalore with Historical Flood Risk
Based on past flood events, the following areas have had significant flooding concerns: Bellandur, Varthur, HSR Layout, Koramangala, Hoodi, Mahadevapura, and parts of Whitefield near the Varthur Lake catchment. This is not exhaustive , flooding can occur in any area where drainage is blocked or lake buffers have been violated.
What to Do
- Ask your property lawyer to conduct a lake buffer zone and SWD proximity check as part of due diligence
- Visit the property during or immediately after a heavy rain to assess drainage conditions
- Check BBMP GIS for water body proximity before signing any agreement
- Avoid properties where the building plan approval looks questionable or the builder cannot explain the lake buffer compliance
Our property due diligence service at Clawrity includes an environmental and zoning check for water body proximity as part of our comprehensive verification. See also: property document verification checklist for Bangalore.