Flood Risk Analysis for India
See exactly when any plot in India has flooded, how often, and how recently — verified from 26 years of ISRO satellite imagery.
What is a flood, and how does it damage property?
A flood is any temporary inundation of normally dry land. In India, floods take several distinct forms — and the type of flood determines what your land is actually exposed to. Knowing this is the foundation of any flood risk analysis.
The four kinds of flooding in India
Riverine flooding is the most common type. Rivers overflow their banks during monsoon (June–September) or when upstream dams release water without warning. The Krishna, Godavari, Brahmaputra, Yamuna, and Ganga basins are the most exposed. Riverine floods arrive slowly and recede slowly — water can sit on a plot for days or weeks. The Andhra Pradesh floods of September 2024 submerged large parts of Krishna and Guntur districts for over a week.
Urban or flash flooding happens when heavy rainfall overwhelms a city’s drainage capacity. It arrives within hours and recedes in days. Low-lying urban plots, basements, and ground-floor properties suffer the most. Most Indian cities have grown faster than their drainage networks, which means this kind of flood is becoming more common every year. Recent examples include Hyderabad 2020 (Musi flood), Chennai 2015, Mumbai 2005, and Bengaluru 2022.
Coastal or cyclonic flooding happens when storm surges from cyclones combine with high tides to push seawater inland. Coastal plots in Andhra Pradesh, Odisha, Tamil Nadu, West Bengal, and Kerala are most exposed. Saltwater also leaves the soil unusable for agriculture for 2–3 monsoon cycles afterward — a long-term cost that goes well beyond the immediate damage. Cyclone Fani in 2019 and Phailin in 2013 are recent examples.
Cloudburst or hill flooding is the deadliest type. Sudden, intense rainfall in hill regions triggers landslides and river bursts that can destroy entire properties without warning. Plots in Himachal, Uttarakhand, Kerala hills, Sikkim, and the Western Ghats are most exposed. Uttarakhand 2013, Kerala 2018, Himachal 2023, and Wayanad 2024 are recent examples — each one wiped out entire villages.
How floods damage land and structures
The visible water is only part of the story. Floods leave behind costs that show up months or years after the event:
- Foundations. Standing water erodes soil around foundations and reduces bearing capacity. Repeated flooding leads to differential settlement, structural cracks, and eventually unsafe buildings.
- Walls and plaster. Flooded walls absorb water for weeks after the visible flood has gone. Lime plaster fails, paint peels, and the embedded steel reinforcement starts corroding from within.
- Electrical and plumbing. All below-flood-level wiring needs full replacement after a major flood. Wet wiring left in place becomes a fire hazard that persists for years.
- Soil productivity. Coastal saline floods poison agricultural soil for years. Riverine sediment can either fertilize or contaminate the land, depending on what was upstream.
- Property boundaries. When rivers change course during major floods, legal boundaries and ground reality stop matching. Revenue records may need to be re-surveyed before any sale.
- Resale and lending. Banks, insurers, and serious buyers all check flood history. Once a plot has a flood record, that information stays attached to it — and shows up in every future due-diligence.
The hidden financial cost of flood-prone land
Flood risk doesn’t show up in a sale deed, a property listing, or a broker’s pitch. By the time you find out, the cheque is already cleared. The real cost of buying flood-prone land falls into four buckets:
Insurance and lending. Home insurance premiums for flood-prone parcels run 3–5× higher than for safe land — and some insurers refuse coverage entirely in NRSC-flagged zones. Banks reduce loan-to-value ratios, so a ₹1 crore plot may be sanctioned for only ₹60–70 lakhs. Lenders may also insist on additional structural inspections at the borrower’s cost.
Construction. Foundations on flood-prone land need plinth elevation 1.5–3 ft above the historical high-water mark, waterproof basements, and corrosion-resistant rebar. That alone adds ₹400–800 per square foot to structural cost. Drainage, slope grading, and damp-proofing add more — every monsoon, forever.
Resale. Plots that flooded in the last 5 years sell at 20–40% discount when they sell at all. Once a plot has a flood record, every future buyer’s due-diligence will find it. The discount becomes permanent.
Personal and family. The 2024 Andhra Pradesh floods damaged property worth over ₹3,000 crores across Krishna and Guntur. Crops, machinery, stored goods — gone in hours. Health risks from waterborne disease and mold persist for months. Flood-damaged homes typically need 6–12 months of rebuilding before they’re livable again.
Why historical flood data is the most reliable predictor
Flood models can predict future risk based on rainfall projections, but they remain estimates. Historical satellite observations show what actually happened. A plot that has flooded 4 times in the last 26 years will almost certainly flood again — the underlying topography, drainage, and proximity to water bodies don’t change quickly.
This is why insurance companies, banks, and revenue departments all use historical flood records as the primary screening tool for any new land transaction. This page gives you access to the same data they use, for free.
What do these numbers mean?
The result card shows two parallel views — what happened at your exact plot, and what happened in the surrounding area. Here’s how to read each metric.
How the analysis works
Three steps. Under two seconds. No setup.
You mark the plot
Draw the exact boundary on the map, drop a pin at the centre, or paste an address. Works for plots from 1 cent to 100 acres.
We check 26 years of satellite floods
Your plot boundary is compared against every flood event recorded by NRSC’s satellite imagery from 1998 through 2024 — that’s 118 distinct events across Andhra Pradesh and Telangana, plus a binary inundation map for the rest of India.
You see exactly what happened
A timeline of dated events, the percentage of your plot that flooded in each, the closest river, and a clear verdict from “Very Low” to “Very High” flood risk.
Methodology and data sources
We use government data, not models. Every flood polygon on our map was directly observed from satellite imagery by ISRO's NRSC.
Where the data comes from
The single source is the NRSC NDEM Flood Hazard Atlas — the National Remote Sensing Centre’s archive of satellite-observed flood inundation polygons, published through the National Database for Emergency Management.
How we score risk
For every analysis, we check two things in parallel:
- Location: Did any recorded flood polygon touch your exact plot (within a 100 m boundary)? This produces the “direct hit” verdict and the count of historical flood events at the parcel.
- Locality: How much of your chosen search radius has ever been flooded? This catches risk in the surrounding area, even when your specific plot avoided historical floods.
Coverage and limitations
- Andhra Pradesh and Telangana have per-event records with exact dates — 118 distinct flood events digitised.
- Rest of India has only a binary inundation map — “this area has been flooded at some point between 1998 and 2022”, without per-event dates.
- Urban flash flooding (e.g. Hyderabad Musi 2000) is generally NOT in the dataset — NRSC satellite passes don’t reliably detect short-duration urban floods.