River
Kalu River
129 km from source to mouth · Sri Lanka.
Sri LankaFlows into Laccadive Sea3rd longest in Sri Lanka
In numbers
Length
129km
Average flow
160m³/s
Basin
2,766km²
Drop
34m
from 34 m to 0 m
Country
1
The journey
From source to mouth
129 km of river and 2 stops on the way: 2 towns and cities on its banks, dams, bridges and the tributaries that feed it.
- 0 kmSourceat 34 m
- 10 kmRatnapura47,832 people
- 79 kmKalutara37,081 people
- 79 kmLaccadive Seaat 0 m
Water level along the river (RiverATLAS; the height is exaggerated). Towns: GeoNames and Wikidata; bridges, dams and tributaries: Wikidata.
River in Sri Lanka
At the mouth it carries 158 m³/s on average: an Olympic pool every 16 seconds. It drops from 34 m to 0 m, 0.3 m per kilometre on average. Its basin covers 2,766 km², about the size of LU. 1.3 million people live in it. Highest water: from May to June and from October to November; lowest: February. No large dam holds it back: it is one of the world's free-flowing rivers.
Where to start
- RatnapuraLargest city on its banks · 47,832 people
- Colombo Ratmalana International Airport (RML)Nearest airport with scheduled flights, 59 km from the cityCar hire at CMB airport (Colombo)Discover Cars · Affiliate link↗
- On the water2 ferry piers, marinas, boat rentals and boat ramps along the river (OpenStreetMap)
- From January to FebruaryThe best months to visit
Kalu River, month by month
Highest water: from May to June and from October to November
Lowest water: February. Best months to visit: from January to February.
From about 34 m³/s in the lowest month to 260 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
Some links above are affiliate links: if you book through them we may earn a commission, at no extra cost to you. It never changes what the data on this page says.
The basin
Kalu River: the basin in numbers
2,942 km² of land send their water to this river. This is what lives on it.
- 1.3millionpeople live in the basin
- 429/km²people per km²
- 247maverage altitude of the basin
- 3,679mmof rain a year (basin average)
- 25.8°Caverage air temperature
- 6%protected areas
- 0.1%covered by lakes
What covers the basin
- 39% Forest
- 44% Cropland
- 2% Pasture
- 29% 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
Kalu River: what you find on the way
- 2Ferry piers
- 1River beachesCalido beach Kalutara
From OpenStreetMap, within 1.5 km of the river. Not mapped is not the same as not there.
Cross-checked with our atlases
Kalu 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.
36mountains at the sourcePeakyas
Mountains at the source (36)
Within 15 km of the source, by Peakyas
- Adam's Peak3.4 km away2,243m
- Saptha Kanya10 km away
- Berawagala15 km away
- Gulunewattekanda7.4 km away
- Botiyagala7.4 km away
- Mullidurukanda13 km away
- Pathangala10 km away
- Elladuragala10 km away
28 more on PeakyasOpen Peakyas ↗
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
Kalu River in pictures
Where these numbers come from
| Name, length, places | Wikidata (Q1634407) · 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 | Peakyas — 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.
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Every summit in 3D: summit weather, the 0 °C line, huts and trails.Visit 
waterfalls
Every waterfall: height, flow month by month and when it roars.Coming soonVisit 
islands
Every island from the sea up: size, sea temperature, ferries and 3D.Coming soonVisit 
rivers
Every river from source to sea: the journey, the flow and the basin in numbers.You are here
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Every canyon cut to scale: depth to the floor, rim and floor temperatures, trails and viewpoints.Coming soonVisit