River
Sepik
1,126 km from source to mouth · Papua New Guinea and Indonesia.
Papua New Guinea and IndonesiaFlows into Bismarck Sea1st longest in Papua New Guinea
In numbers
Length
1,126km
Average flow
3,800m³/s
Basin
80,321km²
Drop
2,007m
from 2,007 m to 0 m
Countries
2
The journey
From source to mouth
1,126 km of river and 2 stops on the way: 0 towns and cities on its banks, dams, bridges and the tributaries that feed it.
- 0 kmSourceat 2,007 m
- 735 kmAvatip Lagoon3.6 km²
- 828 kmTegol Lagoon2.2 km²
- 1,126 kmBismarck Seaat 0 m
Water level along the river (RiverATLAS; the height is exaggerated). Towns: GeoNames and Wikidata; bridges, dams and tributaries: Wikidata.
River in Papua New Guinea and Indonesia
At the mouth it carries 3,804 m³/s on average: 1.5 Olympic pools every second. It drops from 2,007 m to 0 m, 1.8 m per kilometre on average. Its basin covers 80,321 km², about the size of CZ. 939,000 people live in it. Highest water: from January to April. No large dam holds it back: it is one of the world's free-flowing rivers.
Where to start
- Angoram VillageA town on its banks
- Wewak International Airport (WWK)Nearest airport with scheduled flights, 69 km from the city
- On the water1 ferry piers, marinas, boat rentals and boat ramps along the river (OpenStreetMap)
- From June to AugustThe best months to visit
Sepik, month by month
Highest water: from January to April
Best months to visit: from June to August.
From about 2,800 m³/s in the lowest month to 5,300 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
Sepik: the basin in numbers
80,105 km² of land send their water to this river. This is what lives on it.
- 939,000people live in the basin
- 12/km²people per km²
- 527maverage altitude of the basin
- 2,973mmof rain a year (basin average)
- 24.4°Caverage air temperature
- 3%protected areas
- 0.6%covered by lakes
What covers the basin
- 53% Forest
- 6% Cropland
- 1% Pasture
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
Sepik: what you find on the way
From OpenStreetMap, within 2.3 km of the river. Not mapped is not the same as not there.
Cross-checked with our atlases
Sepik 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.
2lakes on its wayLakeyas
3mountains at the sourcePeakyas
Lakes and reservoirs (2)
Lakes it flows through, by Lakeyas
- Avatip Lagoonkm 6323.6km²
- Tegol Lagoonkm 7122.2km²
Lakeyas is coming soonOpen Lakeyas ↗
Mountains at the source (3)
Within 15 km of the source, by Peakyas
- Mount Wamtakin8.8 km away
- Mount Kweirok15 km away
- Mount Burumsakia8.4 km away
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
Sepik in pictures
Tributaries
Where it flows, and what flows into it
Tributaries (2)
Also: Yapsiei River, Idam River
Where these numbers come from
| Name, length, places | Wikidata (Q848308) · CC0 |
|---|---|
| Course, profile, basin | RiverATLAS v1.0 (HydroATLAS, Linke et al. 2019) · CC BY 4.0 — followed along the river network from the point 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, 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?
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