NRCan Flood Susceptibility: How Likely Land Is to Flood
Natural Resources Canada's Flood Susceptibility Mapping shows how likely land across Canada was to flood from 2000 to 2023, at 30 m. Township Canada shows it as a map layer under the survey grid.
What it is
Flood susceptibility describes how likely a piece of land is to flood, based on where floods have happened before and on the conditions that tend to come with them. Natural Resources Canada (NRCan) publishes a national Flood Susceptibility Mapping series, produced by the Canada Centre for Mapping and Earth Observation. Township Canada carries the present-day estimate, which averages susceptibility over 2000 to 2023 at a 30-metre resolution.
NRCan built the maps with XGBoost, a machine learning method that combines many small decision trees into one prediction. The model learns from historic flood events together with (1) land characteristics such as elevation, soil type, land cover, and vegetation, and (2) seasonal weather such as rainfall and temperature. NRCan ran the model many times on slightly different samples of the data to measure how stable its answers are.
What it carries
Every 30 m cell carries one value from 0 to 100, NRCan's calibrated probability of flood susceptibility. A higher value means the land was more likely to flood in a given year over 2000 to 2023. There are no classes or cut-offs, so read it as a continuous scale.
Township Canada shows the values unchanged, in NRCan's own colour ramp: pale yellow for low values, through green and teal, to dark blue for high values. Lakes, rivers, and some nearshore waters also carry values and usually read high.
Coverage and refresh
The present-day estimate covers all of Canada, from Lake Erie to the Arctic islands. NRCan published it in March 2026, and we refresh the layer when NRCan releases a new edition.
Contains information licensed under the Open Government Licence - Canada. Source: Natural Resources Canada - Flood Susceptibility Mapping.
How Township Canada shows it
Flood Susceptibility is a map layer on every paid plan. Open Map Layers, expand Natural, and turn on Flood Susceptibility. It draws from the national view down to street level and sits under the survey grid, so you can read each quarter section and LSD against it. The layer is on the map only; the parcel report does not include a flood card.
How to read it
NRCan intends these maps for patterns and trends at regional and national scales. In its own words, they are not meant for "predicting flooding at individual properties or supporting engineering or building design decisions." How much weight to give the layer depends on your use case:
- Screening a list of parcels: use it to flag which quarter sections sit in higher-susceptibility ground, then look closer at those first.
- Planning across a region: use it to compare river valleys, basins, and municipalities, where the 2000 to 2023 pattern is the signal.
- A decision about one property or structure: treat it as context only, and rely on provincial flood hazard maps and site-specific assessment.
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