River
Mahaweli River
335 km from source to mouth · Sri Lanka.
Sri LankaFlows into Bay of Bengal1st longest in Sri Lanka
In numbers
Length
335km
Average flow
240m³/s
Basin
10,000km²
Drop
571m
from 571 m to 0 m
Country
1
The journey
From source to mouth
335 km of river and 10 stops on the way: 2 towns and cities on its banks, dams, bridges and the tributaries that feed it.
- 0 kmHorton Plains National Parkat 571 m
- 10 kmKotmale Rivertributary
- 21 kmGampola24,283 people
- 46 kmKandy111,701 people
- 52 kmPolgolla Barrage
- 82 kmVictoria Dam
- 82 kmVictoria Falls
- 107 kmRandenigala Reservoir20 km²
- 142 kmSorabora Wewa4.7 km²
- 231 kmManampitiya Bridge
- 333 kmGangai Bridge
- 335 kmBay of Bengalat 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 236 m³/s on average: an Olympic pool every 11 seconds. It drops from 571 m to 0 m, 1.7 m per kilometre on average. Its basin covers 10,000 km², about the size of LB. 3.2 million people live in it. Highest water: from December to January; lowest: from June to September. Dams and reservoirs hold back a large share of its water (33% of a year's flow).
Where to start
- KandyLargest city on its banks · 111,701 people
- Bandaranaike International Colombo Airport (CMB)Nearest airport with scheduled flights, 84 km from the cityCar hire at CMB airport (Colombo)Discover Cars · Affiliate link↗
- From February to March and JuneThe best months to visit
Mahaweli River, month by month
Highest water: from December to January
Lowest water: from June to September. Best months to visit: from February to March and June.
From about 120 m³/s in the lowest month to 520 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
Mahaweli River: the basin in numbers
10,161 km² of land send their water to this river. This is what lives on it.
- 3.2millionpeople live in the basin
- 321/km²people per km²
- 482maverage altitude of the basin
- 2,030mmof rain a year (basin average)
- 24.7°Caverage air temperature
- 29%protected areas
- 1.8%covered by lakes
- 2.5km³held in reservoirs
What covers the basin
- 49% Forest
- 33% Cropland
- 5% Pasture
- 22% 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
Mahaweli River: what you find on the way
- 1Weirs
From OpenStreetMap, within 1.8 km of the river. Not mapped is not the same as not there.
Cross-checked with our atlases
Mahaweli 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.
1waterfall on the riverCascadyas
2lakes on its wayLakeyas
16beaches at the mouth and on the banksCoastya
22mountains at the sourcePeakyas
Waterfalls (1)
On the river, by Cascadyas
- Victoria Fallskm 67
Cascadyas is coming soonOpen Cascadyas ↗
Lakes and reservoirs (2)
Lakes it flows through, by Lakeyas
- Randenigala Reservoirkm 8720km²
- Sorabora Wewakm 1164.7km²
Lakeyas is coming soonOpen Lakeyas ↗
Beaches (16)
At the mouth (25 km) and on the banks, by Coastya
- Yard Cove13 km away · cove30.0°C
- Welcombe Hotel Cove12 km away · cove30.0°C
- North Cove14 km away · cove30.0°C
- Mud Cove13 km away · cove30.0°C
- Minden Cove11 km away · cove30.0°C
- Mangrove Cove13 km away · cove30.0°C
- Malay Cove12 km away · cove30.0°C
- Fisherman’s Corner12 km away · cove30.0°C
8 more on CoastyaOpen Coastya ↗
Mountains at the source (22)
Within 15 km of the source, by Peakyas
- Saptha Kanya15 km away
- Veyangala15 km away
- Kalugalgammana12 km away
- Aslenakanda9.4 km away
- Bulatwalakanda9.8 km away
- Kokatiyagala8.0 km away
- Pallebage8.5 km away
- Kehelgamugala6.6 km away
14 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
Mahaweli River in pictures
Tributaries
Where it flows, and what flows into it
Tributaries (1)
Also: Kotmale River
Where these numbers come from
| Name, length, places | Wikidata (Q1518007) · 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 | Cascadyas, Lakeyas, Coastya, 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.



