River
Severn River
940 km from source to mouth · Canada.
CanadaFlows into Hudson Bay
In numbers
Length
940km
Average flow
640m³/s
Basin
101,000km²
Drop
300m
from 300 m to 0 m
Country
1
The journey
From source to mouth
940 km of river and 17 stops on the way: 0 towns and cities on its banks, dams, bridges and the tributaries that feed it.
- 0 kmDeer Lakeat 300 m
- 6 kmDeer Lake152 km²
- 83 kmFavourable Lake71 km²
- 155 kmOpasquia Lake30 km²
- 191 kmAngekum Lake184 km²
- 260 kmSandy Lake484 km²
- 344 kmWindigo Rivertributary
- 368 kmLookout Lake1.6 km²
- 372 kmMuskrat Dam Lake61 km²
- 376 kmAxe Lake7.2 km²
- 418 kmAsipoquobah Lake14 km²
- 453 kmMichikan Lake6.6 km²
- 492 kmSevern Lake99 km²
- 508 kmPiko Lake1.9 km²
- 554 kmWapisew Lake2.4 km²
- 707 kmSachigo Rivertributary
- 781 kmFawn Rivertributary
- 885 kmBeaver Rivertributary
- 940 kmHudson Bayat 0 m
Water level along the river (RiverATLAS; the height is exaggerated). Towns: GeoNames and Wikidata; bridges, dams and tributaries: Wikidata.
River in Northwestern Ontario, Canada
At the mouth it carries 635 m³/s on average: an Olympic pool every 3.9 seconds. It drops from 300 m to 0 m, 0.3 m per kilometre on average. Its basin covers 101,000 km², about the size of CS. 5,143 people live in it. Highest water: from June to August; lowest: from January to April. No large dam holds it back: it is one of the world's free-flowing rivers.
Where to start
- Kayak and canoe110 put-ins and rapids mapped (OpenStreetMap)
- From July to AugustThe best months to visit
Severn River, month by month
Highest water: from June to August
Lowest water: from January to April. Freezing months (average below −4 °C): from November to March. Best months to visit: from July to August.
From about 530 m³/s in the lowest month to 750 m³/s in the highest. An estimate: the monthly flow is modelled from the lowest and highest months of WaterGAP (RiverATLAS, 1971–2000) and the rain and snow along the river (WorldClim). Dams change the real rhythm. The chip is the average air temperature; below it, the month's rain.
Plan the trip
Plan the trip: boat trips, a bed by the river, a car
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The basin
Severn River: the basin in numbers
101,172 km² of land send their water to this river. This is what lives on it.
- 5,143people live in the basin
- 0/km²people per km²
- 228maverage altitude of the basin
- 581mmof rain a year (basin average)
- -2.6°Caverage air temperature
- 3%protected areas
- 9.3%covered by lakes
- 21%permafrost
What covers the basin
- 71% Forest
RiverATLAS (HydroATLAS v1.0, CC BY 4.0): land cover, people, protected areas, glaciers and dams over the whole basin upstream of the mouth.
Along the river
Severn River: what you find on the way
- 1WaterfallsAkem Falls
- 110Rapids
From OpenStreetMap, within 2.4 km of the river. Not mapped is not the same as not there.
Cross-checked with our atlases
Severn River in our other atlases
What our sister atlases know about the waterfalls on this river, the lakes it flows through, the beaches at its mouth, the mountains where it rises and the islands off its mouth.
13lakes on its wayLakeyas
Lakes and reservoirs (13)
Lakes it flows through, by Lakeyas
- Deer Lakekm 5152km²
- Favourable Lakekm 7471km²
- Opasquia Lakekm 13830km²
- Angekum Lakekm 170184km²
- Sandy Lakekm 232484km²
- Muskrat Dam Lakekm 33261km²
- Michikan Lakekm 4046.6km²
- Severn Lakekm 44099km²
5 more on LakeyasLakeyas is coming soonOpen Lakeyas ↗
From space
The source and the mouth, seen from orbit


Sentinel-2 cloudless 2016 by EOX IT Services GmbH (contains modified Copernicus Sentinel data 2016), CC BY 4.0. The glowing line is the river as drawn by RiverATLAS.
Photos
Severn River in pictures

Tributaries
Where it flows, and what flows into it
Tributaries (7)
Also: Fawn River, Sachigo River, Beaver River, Windigo River, Flanagan River, Fox River, Makoop River
Where these numbers come from
| Name, length, places | Wikidata (Q1239783) · CC0 |
|---|---|
| Course, profile, basin | RiverATLAS v1.0 (HydroATLAS, Linke et al. 2019) · CC BY 4.0 — followed from the source to the mouth given by Wikidata |
| Flow | WaterGAP (RiverATLAS), 1971–2000 · CC BY 4.0 |
| Climate along the river | WorldClim (RiverATLAS), 1970–2000 · CC BY 4.0 |
| Towns, bridges, dams | Wikidata · CC0; GeoNames · CC BY 4.0 |
| Along the river | © OpenStreetMap contributors · ODbL |
| Images | EOX Sentinel-2 cloudless 2016 · CC BY 4.0; Wikimedia Commons |
| Our other atlases | Lakeyas — Wikidata · CC0; © OpenStreetMap contributors · ODbL; GeoNames · CC BY 4.0; HydroLAKES · CC BY 4.0; NOAA OISST |
Every source and licence is on the data sources page.
The family
Do you prefer beaches, lakes, mountains, waterfalls, islands, rivers or canyons?
Same idea, other landscapes: field atlases built on open data, month by month, in seven languages.