# How do I check flood risk for a factory site in India?

Canonical: https://senseible.earth/answers/check-flood-risk-for-factory-site-india

Check four things: whether the site lies in a mapped flood hazard zone on NRSC's atlases and Bhuvan, the highest flood level recorded nearby, what future heavy rain projections show, and what the ground tells you on a site visit. Compare your plinth level with the likely flood depth before you buy or build.

## Step 1: mapped hazard zones

NRSC, part of ISRO, has published flood hazard atlases for flood-prone states such as Assam and Odisha, built from years of satellite images of inundation, and its flood layers can be viewed on the Bhuvan portal. Locate the site and note whether the plot was flooded in past events and how often. For coastal sites, also check storm surge and cyclone maps.

## Step 2: local flood levels

- Find the nearest river gauge in the Central Water Commission flood forecasting network and its danger and highest flood levels.
- Ask the state water resources department or municipal body for the highest flood level (HFL) recorded at or near the site.
- Note the plot's ground level against the nearest river, nallah or drain, and whether roads around it sit higher and could trap water.
- Urban sites often flood from blocked drains during heavy rain, not from rivers, so ask neighbours about waterlogging.

## Step 3: how it may change

The IPCC AR6 Working Group I Interactive Atlas shows projected changes in heavy rainfall, such as the wettest day of the year, for your region under different warming levels. WRI Aqueduct Floods gives modelled riverine and coastal flood depths for return periods such as 1 in 100 years. Both are coarse; use them to rank sites, not to set a plinth level alone.

## Step 4: decide

- Plinth below the 1 in 100 year flood depth plus a safety margin, or the plot flooded in recent mapped events: raise the plinth, store stock and electricals above the HFL, add bunds and non-return valves, or look elsewhere.
- Plinth clear of both: record the evidence and move on.
- Keep screenshots, coordinates, dates and dataset names; lenders and insurers ask for them.

## Illustrative screening of one plot

- Modelled 1 in 100 year riverine flood depth at the plot: 0.6 m; safety margin you choose: 0.3 m
- Required plinth: 0.6 + 0.3 = 0.9 m above ground; existing plinth 0.4 m, so raise by 0.5 m
- Expected yearly loss if unprotected: stock and machines Rs 2 crore x 40% damage x 1% annual chance = Rs 80,000 a year

Depth, margin and damage share are illustrative. A 1 in 100 year flood has about a 1% chance each year, and about a 26% chance over 30 years.

## What Senseible does here

Senseible turns your fuel and electricity invoices into Scope 1 and 2 figures linked to their source files, the transition side of a lender's climate risk review, and its climate risk page frames the physical risk questions. Keep your flood screenshots, coordinates and dates with those records.

- [Climate risk assessment for a small business](https://senseible.earth/answers/climate-risk-assessment-for-small-business)
- [Free climate hazard data in India](https://senseible.earth/answers/free-climate-hazard-data-india-factory)
- [Climate risk](https://senseible.earth/climate-risk)
- [RBI climate risk disclosure for borrowers](https://senseible.earth/answers/rbi-climate-risk-disclosure-for-borrowers)

Sources: [IPCC AR6 Working Group I, including the Interactive Atlas](https://www.ipcc.ch/report/ar6/wg1/)

Last reviewed 2026-10-16.