When Bengaluru flooded in August 2022, the water did not choose its victims at random. Much of it pooled where buildings had crept over the city's old storm water drains, the rajakaluves that once carried monsoon runoff between its lakes. In the months that followed, the civic body drew up lists of structures on those drains and sent in the excavators. For a buyer, the lesson landed hard: a plot can have clean papers and still sit on a drain the city intends to reclaim. Checking for that before you pay is now part of basic due diligence in Bengaluru.

The short answer. Rajakaluves are the storm water drains that thread through Bengaluru, and the Revised Master Plan provides for no construction buffer zones on either side of them, larger for bigger drains and smaller for minor ones. A clean title does not tell you whether your plot touches a drain or its buffer, and banks often refuse loans on properties that do. The trade-off is modest: verifying against official drain maps and old survey records takes time and sometimes a professional, but it protects you from notices, demolition and a loan you cannot get.

What is a rajakaluve and why does it matter to a buyer?

A rajakaluve is a storm water drain, part of the natural drainage network that moves rainwater across Bengaluru. It matters to a buyer because construction is restricted within a buffer zone alongside these drains, and the city has shown, since the 2022 floods, that it will act against structures that ignore those limits. The National Green Tribunal and the courts have pushed enforcement, and heavy penalties have been imposed on developers who built over drains. That history means a property near a drain is not a theoretical risk but a documented one, and the question of where the drain runs belongs at the start of your diligence, not after you have paid.

The deeper problem is that drains are easy to hide. A drain can be narrowed, covered or built over so that nothing is visible from the road, yet the alignment survives in old revenue and survey records and in the city's drain maps. A buyer who looks only at the plot as it appears today can miss a drain that the authorities still recognise on paper. That gap between what you see and what the record shows is exactly where trouble lives.

How large is the buffer zone?

The buffer depends on the size of the drain, and it is set out in the city's master plan rather than left to guesswork. The Revised Master Plan provides for buffer zones on either side of primary, secondary and tertiary drains, with the buffer widest for the largest primary drains and narrower for smaller tertiary ones. The important caution is that both the exact figure and the classification of a specific drain have been the subject of dispute, and the drain maps kept by different authorities have not always agreed. For that reason, do not rely on a number you half remember or a figure from a broker. Confirm the buffer that applies to your specific plot against the official records for the specific drain beside it.

This is a case where precision matters and approximations are dangerous. A plot that is safe against a small drain could be inside the buffer of a larger one classified differently. Treat the buffer as something to be established for your exact parcel, in writing, rather than a rule of thumb you apply from memory.

How do you check a plot against the drains?

You check by comparing the plot's survey number and boundaries against the official rajakaluve maps and the old village survey records. The alignment of a drain is preserved in these records even when the ground has changed, so the survey number is your anchor. Where a layout or building plan is involved near a drain, the storm water drain division of the civic body is the authority that can confirm compliance, and its clarity is worth seeking before you commit. Because the maps held by the civic body and the development authority have not always matched, cross checking more than one official record is prudent rather than paranoid. A detailed legal account of the Bengaluru demolition drive and the buffer framework is available in this analysis of the BBMP action against drain encroachments.

This is a check where an experienced local surveyor earns their fee. Reading a survey number against a drain map, and reconciling maps that disagree, is not a job for a first time buyer with a phone. Pay for the expertise, get the finding in writing, and keep it with your other records. The cost is trivial against the price of the home and the risk you are ruling out.

What does a buffer problem do to your home loan?

It can stop the loan entirely, which is often the first hard signal a buyer gets. Lenders are wary of properties that fall inside a drain buffer, because the structure carries demolition risk and the title becomes hard to enforce, so banks frequently decline loans on such plots. If a lender's own valuer or legal team flags a drain issue, treat that as valuable free diligence rather than an obstacle to argue around. A bank saying no to a specific property is sometimes the clearest warning you will receive, and it is far cheaper to heed it than to fund the purchase another way and inherit the problem.

The reverse is also useful. Running the property past a lender early, before you are emotionally committed, turns the bank's caution into an extra check working in your favour. If the loan sails through after proper valuation, you have one more independent party comfortable with the property. If it stalls on a drain concern, you have learned something important while you can still walk away.

How does this fit with your other Bengaluru checks?

The drain check sits alongside your title and civic record checks, and does not replace any of them. A full title search and a lawyer's review remain essential, and our guide to verifying a property title in Bengaluru covers that ground. Civic records matter too, and confirming the khata and municipal status is part of the same discipline, which our explainer on the BBMP e-khata requirement sets out. The drain check answers a different and specific question: does this parcel sit on or beside a storm water drain the city recognises. Run all three, because each catches something the others do not.

Think of these as separate instruments measuring different risks. Title work confirms ownership, civic records confirm municipal standing, and the drain check confirms location against the city's drainage. Only when all three come back clean, documented and dated, should you move toward payment with confidence.

What are the seven steps to check for rajakaluve risk?

Work through these before you pay any advance.

1. Collect the exact survey numbers and boundaries from the sale deed and any layout or plan approval.
2. Identify every drain, nala and low lying channel near the plot from local knowledge and a site visit.
3. Compare the survey number against the official rajakaluve maps and old village survey records.
4. Cross check the civic body and development authority maps, since they have not always agreed.
5. For plots near a drain, seek clarity from the storm water drain division before committing.
6. Ask your lender early whether it will finance the specific property, and treat any drain concern seriously.
7. Get every finding in writing from a surveyor or lawyer, and keep it dated with your records.

Is a plot away from any visible drain automatically safe?

No, the absence of a visible drain is reassuring but not conclusive on its own. Drains have been covered, narrowed or built over across the city, and the alignment that matters is the one recorded in official maps and survey documents, not the one you can see from the gate. A plot that looks perfectly dry and ordinary can still intersect a recorded drain. That is why the check has to be done against the records for the specific survey number, and why a clean visual impression should never substitute for that documentary check. Verify on paper, confirm with the authority where needed, and only then treat the drainage risk as ruled out.

Frequently asked questions

What is a rajakaluve buffer zone? A rajakaluve is a storm water drain in Bengaluru, and the Revised Master Plan provides for no construction buffer zones on either side of these drains, wider for larger primary drains and narrower for smaller ones. Construction inside the buffer is restricted, and the civic body has removed structures there, so buyers must check a plot against official drain records.

How do I check if a plot is near a rajakaluve? Compare the plot's survey number and boundaries against the official rajakaluve maps and the old village survey records, where a drain's alignment survives even if the ground has changed. Because civic and development authority maps have not always matched, cross check more than one, and seek clarity from the storm water drain division for any plot near a drain.

Will a bank give a loan on a property near a drain? Often not. Lenders are wary of properties inside a drain buffer because of demolition risk and title difficulties, and banks frequently decline loans on such plots. This makes an early loan enquiry a useful extra check. If a lender flags a drain concern during valuation, treat it as important free diligence rather than an obstacle to work around.

Does a clean title protect me from rajakaluve action? No. A clean title confirms ownership and the transfer chain, but it does not reveal whether the plot sits on or beside a recorded storm water drain. Drain risk is a location question answered by official drain maps and survey records, not by title documents. Run the drain check separately, alongside your full title and civic record verification, before paying.

Last updated 2026-08-28. PropNewz Team.