River
Tonle Sap River
112 km from source to mouth · Cambodia.
CambodiaFlows into Mekong River3rd longest in Cambodia
In numbers
Length
112km
Average flow
1,600m³/s
Basin
85,000km²
Drop
1m
from 5 m to 4 m
Country
1
The journey
From source to mouth
112 km of river and 12 stops on the way: 5 towns and cities on its banks, dams, bridges and the tributaries that feed it.
- 0 kmTonle Sapat 5 m
- 37 kmBeng Totung Thngnay0.7 km²
- 37 kmBeng Stung Rat1.3 km²
- 71 kmBoeng Kanlaeng Chhdaor0.4 km²
- 74 kmBeng Prang0.6 km²
- 75 kmLongveaek9,606 people
- 101 kmBeng Reachisey0.6 km²
- 102 kmChrang Chamreh Muoy22,911 people
- 108 kmBoeng Kak Muoy13,861 people
- 108 kmChroy Changva Bridge
- 109 kmTœ̆k L’ák9,334 people
- 109 kmBoeung Kak0.7 km²
- 110 kmPhnom Penh1,573,544 people
- 112 kmMekong Riverat 4 m
Water level along the river (RiverATLAS; the height is exaggerated). Towns: GeoNames and Wikidata; bridges, dams and tributaries: Wikidata.
River in Cambodia
At the mouth it carries 1,640 m³/s on average: an Olympic pool every 1.5 seconds. Its basin covers 85,000 km², about the size of AT. 6.7 million people live in it. Highest water: from September to October; lowest: from January to April. No large dam holds it back: it is one of the world's free-flowing rivers.
Where to start
- Phnom PenhLargest city on its banks · 1,573,544 people
- Techo International Airport (KTI)Nearest airport with scheduled flights, 22 km from the city
- On the water29 ferry piers, marinas, boat rentals and boat ramps along the river (OpenStreetMap)
- From December to JanuaryThe best months to visit
Tonle Sap River, month by month
Highest water: from September to October
Lowest water: from January to April. Best months to visit: from December to January.
From about 520 m³/s in the lowest month to 4,200 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
Tonle Sap River: the basin in numbers
88,240 km² of land send their water to this river. This is what lives on it.
- 6.7millionpeople live in the basin
- 78/km²people per km²
- 88maverage altitude of the basin
- 1,475mmof rain a year (basin average)
- 27.1°Caverage air temperature
- 20%protected areas
- 3.1%covered by lakes
What covers the basin
- 31% Forest
- 23% Cropland
- 9% Pasture
- 2% Towns and cities
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
Tonle Sap River: what you find on the way
- 29Ferry piersSamaki 028 Ferry Dock, Marina Port of Phnom Penh, Sohka Hotel Ferry and 26 more
From OpenStreetMap, within 2.4 km of the river. Not mapped is not the same as not there.
Cross-checked with our atlases
Tonle Sap 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.
6lakes on its wayLakeyas
Lakes and reservoirs (6)
Lakes it flows through, by Lakeyas
- Beng Totung Thngnaykm 440.7km²
- Beng Stung Ratkm 451.3km²
- Boeng Kanlaeng Chhdaorkm 860.4km²
- Beng Prangkm 890.6km²
- Beng Reachiseykm 1210.6km²
- Boeung Kakkm 1300.7km²
Lakeyas 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
Tonle Sap River in pictures




Tributaries
Where it flows, and what flows into it
It flows into
Mekong RiverWhere these numbers come from
| Name, length, places | Wikidata (Q939958) · 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.