Bengaluru's flooding is concentrated, not random. The city's own list counts about 209 to 210 flood-prone locations, and the same areas reappear in report after report: the Bellandur–Mahadevapura belt in the east, HSR Layout, Koramangala's low-lying layouts and Silk Board in the south-east, and pockets around Hebbal, Hennur, Yelahanka and RR Nagar. Most sit near lakes or along the primary stormwater drains, the rajakaluves.

Updated 13 October 2026. We name areas, never projects. Lake buffer rules changed in February 2026, so older guides quoting a uniform 30-metre buffer are out of date; the legal position is explained below.

Which areas in Bangalore are flood prone?

These localities appear in official lists or in dated major-news reports of flooding. A locality on this list is not uniformly at risk; risk is street-level and depends on elevation and distance from a lake or drain.

  • East, Mahadevapura zone: Bellandur, Mahadevapura, Whitefield, KR Puram, Marathahalli and Sai Layout. The News Minute reported in May 2025 that in Mahadevapura even 15–25 mm of rain now causes serious flooding.
  • South-east: HSR Layout, Koramangala (including ST Bed Layout), Silk Board junction, BTM Layout, Bommanahalli and the Hosur Road approach to Electronic City. On 19 May 2025 the city recorded 105.5 mm of rain and Deccan Herald listed HSR Layout, ST Bed Layout and Silk Board among the worst-hit.
  • Bengaluru South corporation hotspots for monsoon 2026: Hulimavu Lake junction, Sagar junction, HSR Layout 14th Main and 5th Main, Sony World junction, the Outer Ring Road, Bellandur–Iblur junction, the Sarjapur Road junction near Wipro and Roopena Agrahara–Madiwala (NewsKarnataka, 18 June 2026).
  • North and north-east: Hebbal, RT Nagar, Nagavara, HBR Layout, Hennur and Yelahanka. Deccan Herald listed parts of Nagavara, HBR Layout and Hennur among areas flooded in May 2025.
  • Central and west: Wilson Garden, Shanthinagar, Malleshwaram, Rajajinagar and RR Nagar.
  • September 2026 waterlogging: Oneindia reported waterlogging on 15 September at Domlur, Ejipura, Richmond Circle, MG Road, Yelahanka, Rajajinagar, JP Nagar 8th Phase, Malleshwaram, Whitefield and KR Puram.

Is there an official flood map for Bangalore?

There is an official list rather than a buyer-friendly, parcel-level map. The city's stormwater drain department maintains a list of vulnerable locations: The News Minute reported 209 flood-prone areas in May 2025, with work completed at 166 and 43 remaining, and Oneindia reported 210 in September 2026, along with about 633 drainage catchments and 840–860 km of primary and secondary drains.

An earlier version of the list, published by Citizen Matters in 2020, broke it down by zone: West and RR Nagar had the most vulnerable points, but Mahadevapura and Bommanahalli had the most severely vulnerable ones. We did not find a current, official parcel-level flood map for Bengaluru. Use the list, lake maps and a site visit together.

What are the lake buffer zone rules in Bangalore in 2026?

Until February 2026, every lake had a uniform 30-metre no-construction buffer under the Karnataka Tank Conservation and Development Authority (KTCDA) Act. On 18 February 2026, the state notified the KTCDA (Amendment) Act, 2025, which links the buffer to lake size, after the Governor had returned the bill once for clarification (Deccan Herald). The buffers are now:

  • Up to 0.05 acre: no buffer.
  • 0.05 to 0.1 acre: 1 metre.
  • 0.1 to 1 acre: 3 metres.
  • 1 to 10 acres: 6 metres.
  • 10 to 25 acres: 12 metres.
  • 25 to 100 acres: 24 metres.
  • Above 100 acres: 30 metres, unchanged.

Is the new buffer law settled?

Not entirely. The Federation of Bengaluru Lakes said it would challenge the amendment, and experts noted that the National Green Tribunal had a pending suo motu case on the issue. The News Minute reported on 4 September 2026 that petitioners in the Karnataka High Court had challenged the amendment's buffer provisions as unconstitutional; we found no report of a stay.

For a buyer, the practical point is simple. A smaller legal buffer does not make low ground drier. Water still flows to the same low points, so a home six metres from a mid-sized lake may now be legal to build but can still flood. Use the buffer rule as a legal minimum, not a safety margin.

What is the rajakaluve buffer zone?

Rajakaluves are Bengaluru's primary stormwater drains, with secondary and tertiary drains feeding them. The rules here have shifted several times:

  • 2016: the National Green Tribunal ordered 75 metres around lakes and 50, 35 and 25 metres along primary, secondary and tertiary drains.
  • March 2019: the Supreme Court set aside those general buffer directions, while upholding the Tribunal's power to set wider buffers for specific water bodies where restoration requires it. LiveLaw's report of the judgment summarises the Revised Master Plan figures as 30 metres for lakes and 50, 25 and 15 metres for the three drain types.
  • September 2025: the Urban Development Department issued a draft regulation, UDD 468 MNJ 2025 (E), proposing to cut drain buffers to 15, 10 and 5 metres, with objections invited until 30 September 2025 (Citizen Matters; Mongabay India).
  • As of 13 October 2026, we found no report that the drain-buffer draft had been finalised. Because published sources describe the current figures differently, ask the planning authority for the applicable drain buffer in writing for your survey number.

How do you check the lake buffer and flood risk for a specific property?

  • Find the survey number. It is in the sale deed, the khata and the sanctioned plan. For khata types and what each means, see A-Khata, B-Khata and e-Khata in Bengaluru (2026): What a Buyer Must Check Now
  • Check the land record. Karnataka's Dishaank app, from the Revenue Department and the Karnataka State Remote Sensing Applications Centre, shows survey boundaries and flags land classed as lake bed or government land. Land recorded as a tank, kere or kharab is a red flag.
  • Measure the distance to the nearest lake and drain on the survey map and on satellite imagery, then compare it with the buffer for that lake's size or drain type.
  • Read the sanctioned building plan. It should show the setback from any lake or drain, and the approval may carry conditions or no-objection letters relating to water bodies. A missing approval is a reason to stop.
  • Check the plinth and basement. Is the ground floor above the road? Is there a sump pump and a basement drain? Ask whether basement parking has flooded in the last three monsoons.
  • Visit after heavy rain, and ask the watchman, shopkeepers and residents. Look for water marks on compound walls and fresh plaster at low levels.
  • Search the area's name with “flooding” in dated news coverage for the past five years.
  • For an under-construction project, check the Karnataka RERA page for approvals and quarterly updates. Our site-visit checklist: Buying an Under-Construction Flat in Bengaluru: Site-Visit and K-RERA Checklist

Does flood risk affect property prices and resale?

It affects liquidity more than headline rates. Buyers who have seen pictures of flooded streets remember them, and homes in streets that flood repeatedly tend to take longer to sell and to rent. We found no reliable published study quantifying a citywide flood discount for Bengaluru, so be wary of precise figures in marketing or social media.

The more serious risk is legal. A building found to encroach on a lake or drain buffer can face action from the authorities. That is why the survey-number check above matters more than any price argument.

How we suggest you shortlist

Do not cross whole localities off the list. Bellandur, HSR Layout and Hebbal all have streets that rarely flood and streets that flood every year. Shortlist by street and building: higher ground, no lake bed in the land record, a clear setback on the sanctioned plan, and a basement that stayed dry last monsoon.

For one of the most-asked localities in detail, see Bellandur, Bengaluru: Buyer's Guide 2026 — Prices, Metro, Projects and Risks. For the same checklist applied to Chennai, see Flood Prone Areas in Chennai 2026: Area-by-Area Check Before You Buy. And if you are weighing whether to buy at all in 2026, read Will Bangalore Real Estate Crash Due to AI and Tech Layoffs?