Sepik
Sepik is a mapped river in the YearMaps hydrographic index. River courses organise settlement, agriculture and frontier-making more durably than any political boundary, and this reach is indexed against the dams, lakes and cities within its catchment.
- Feature Class
- River
- Coordinates
- -4.26°, 142.76°
About Sepik
The Sepik () is the longest river on the island of New Guinea, and the third largest in Oceania by discharge volume after the Fly and Mamberamo. The majority of the river flows through the Papua New Guinea (PNG) provinces of Sandaun (formerly West Sepik) and East Sepik, with a small section flowing through the Indonesian province of Papua.
The Sepik has a large catchment area, and landforms that include swamplands and mountains. Biologically, the river system is often said to be possibly the largest uncontaminated freshwater wetland system in the Asia-Pacific region. Numerous fish and plant species have been introduced into the Sepik since the mid-20th century.
Encyclopedic summary adapted from Wikipedia: Sepik (CC BY-SA 4.0).
Sepik in Depth
Hydrology
The river has a total length of over 1,100 km (680 mi) and has a drainage basin of over 80,000 km2 (31,000 mi2). Its meandering bed is 250–500 m (820–1,640 ft) wide and averages 8–14 m (26–46 ft) deep. There is a 5-to-10-kilometre-wide (3.1 to 6.2 mi) belt of active meanders along most of its course, that has created a floodplain up to 70 kilometres (43 mi) wide, with extensive backwater swamps. There are around 1,500 oxbow and other lakes in the floodplain, the largest of which are the Chambri Lakes. Its annual sediment load is estimated at 115 million tonnes.
The Sepik basin is largely an undisturbed environment, with no major urban settlements, or mining and forestry activities, in the river catchment. April Salome Forest Management Area is located in Sepik River basin.
History
Local villagers have lived along the river for many millennia and the river has formed the basis for food, transport and culture. There are at least 100 distinct villages and hamlets along the river, and most likely more.
European contact with the river started in 1885, shortly after Germany established colonial control over German New Guinea or Kaiser Wilhelmsland. The river was named by Otto Finsch, Kaiserin Augusta, after the German Empress Augusta. The colony was initially managed by the German New Guinea Company (Neuguinea-Kompagnie). Finsch, in the ship Samoa, entered only the estuary. He returned a year later, and the Samoa launched a smaller vessel that navigated about 50 kilometres (31 mi) upstream from its mouth.
Description
The river originates in the Victor Emanuel Range in the central highlands of Papua New Guinea. From its mountain headwaters near Telefomin, it travels north-west and leaves the mountains abruptly near Yapsei. From there it flows into Indonesian Papua, before turning back north-east, for the majority of its journey following the great Central Depression. Along its course it receives numerous tributaries from the Bewani and Torricelli Mountains to the north and the Central Range to the south, including the Yuat River formed by the Lai and the Jimmi.
For most of the Sepik's length, the river winds in serpentine fashion, like the Amazon, to the Bismarck Sea off northern Papua New Guinea.
Sections adapted from Wikipedia: Sepik (CC BY-SA 4.0).
Sepik: Key Facts
| Length | 1,126 km |
|---|---|
| Average discharge | 3,804 m³/s |
| Drainage basin | 80,321 km² |
| Mouth | Bismarck Sea |
| Tributaries | Yapsiei River, Simaiya River |
Facts from Wikidata Q848308 (CC0).
Major River Dossiers
Hand-written studies of the great river systems of history.
Connected Reaches
Nearby watercourses in the same drainage network.
Water Bodies in the Catchment
Settlements Along the Reach
Hydraulic Infrastructure Nearby
Surrounding Terrain
Sepik: Quick Answers
- Where is Sepik?
- Sepik is located in Papua New Guinea and Indonesia, at 4.2592° S, 142.7625° E.
- Are there dams on the Sepik?
- No dam on the Sepik is recorded in the YearMaps dam index, which covers major structures only.