Open source

An open-source civic project. Not affiliated with the Government of Canada.

Flood Watch Canada

Nshipyard Canada · Flood intelligence

Where Canada floods.

Twenty-six years of news-reported flood events, clipped to Canada from the open Groundsource dataset, laid under live rainfall radar and current weather alerts from Environment and Climate Change Canada. History tells you where water has gone before; the live layers show where rain is falling now.

Open the live mapHow the watch flag works
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news-reported flood events in Canada, 2000-2026
…
provinces and territories with recorded events
675
flood hazard study areas in the national inventory
…
flood protection structures inventoried in British Columbia

Live map

History under live weather.

Blue dots are flood events reported in the news since 2010. Toggle the live layers to lay today's rainfall radar and current official alerts over the historical footprint. Nothing here is a forecast: it is the record, plus the weather, side by side.

The record

Twenty-six years of reported floods.

Groundsource turned five million news articles into 2.6 million geo-tagged flood events worldwide. Clipped to Canada, the record shows where reporters wrote about water, which tracks where floods disrupted lives closely enough to be useful, with two biases stated plainly below.

Reported flood events by year

When floods get reported

Events by province and territory

Read the record honestly

  • One storm can produce several rows: the dataset is entity-based, so a single large flood reported in five places is five records, not one event.
  • News coverage is the sensor. English-language outlets dominate, remote floods go under-reported, and dramatic floods get more ink than slow ones.
  • Locations are approximate: each record is a polygon or buffered point from a geocoding step Google rates at about 60% for exact location and timing.

Watch

An honest early signal, not a forecast.

Version 1 does not run a flood model. It applies one documented rule: places with a deep history of reported floods deserve attention whenever heavy rain or an official alert lands on them. Google's Flood Hub runs the calibrated version of this idea; this page shows the ingredients it is built from.

The v1 watch rule

A region is flagged for watch when it ranks in the top quarter of historical reported floods AND either current radar shows significant precipitation over it or an official weather alert covers it. The first half is computed from the record below; the second half you read off the live map above.

Hardest-hit provinces in the record

Ranked by reported flood events, 2000-2026, with each province's peak month.

How to use this page in a storm

  1. Open the live map and turn on precipitation radar plus current alerts.
  2. Find your region in the table: high historical counts plus an active alert is the combination that has preceded the worst Canadian floods.
  3. Check the official alert text by clicking the map, then follow Environment and Climate Change Canada guidance, not this page.

Protection

What stands between water and towns.

British Columbia publishes the only open, province-wide inventory of flood protection works in Canada: dikes, sea walls, pump stations, and the structures that keep them working. The map layer shows them; the counts below come from the province's open warehouse.

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kilometres of dike and flood protection linework inventoried
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appurtenant structures (pump stations, gates, flood boxes)

No other province publishes an equivalent open inventory. Absence from this map is absence of open data, not absence of dikes.

Flood hazard study areas

The Canada Flood Map Inventory lists 675 flood study areas from provincial, territorial, and municipal programs. Each entry links to its owner and publication status.

Method

What this is, and what it is not.

  1. Historical layer: Groundsource (Google Research, CC BY 4.0, Zenodo record 18647054), 2,646,302 events worldwide, 2000-2026. Events were clipped to Canada by testing each record's centroid against Canada Flood Map Inventory province boundaries; … fell inside. Aggregates are committed as JSON in public/data.
  2. Live layers: Environment and Climate Change Canada web services, fetched by your browser at view time. Radar is the 1 km North American precipitation-rate mosaic (RADAR_1KM_RRAI); alerts are the Current-Alerts layer. Neither passes through our servers.
  3. Watch rule v1: top-quartile historical counts per province, combined with live radar and alerts as described above. It is a documented heuristic, not a calibrated forecast, and it is labelled as such everywhere it appears.
  4. Protection layer: BC Geographic Warehouse flood protection works (lines and appurtenant structures), plus the 675-area Canada Flood Map Inventory from Natural Resources Canada.
  5. Refresh: the historical record rebuilds when Groundsource publishes a new version; live layers are always current at view time. Build date is stamped on every aggregate file.
  6. What v1 cannot do: predict water levels, time a flood's arrival, or cover places the news never wrote about. For operational forecasting, see Google's Flood Hub, which trains on this same Groundsource recipe.

Open data

Take the files.

Every aggregate on this page, as JSON, rebuilt from the open sources above. Raw inputs are excluded from the repository; the build script documents the full pipeline.

  • summary.json

    Totals, date range, source citation, build date.

    Download

  • by_province.json

    Reported events per province and territory.

    Download

  • by_year.json

    Reported events per year, 2000-2026.

    Download

  • by_month.json

    Reported events per calendar month.

    Download

  • points.json

    Sampled event locations for the map (2010+, capped).

    Download

  • cfm_studies.json

    675 flood hazard study areas: name, province, date, status, owner.

    Download

  • bc_protection.json

    BC flood protection works: counts and dike kilometres.

    Download