Kapuas River

The Kapuas River (or Kapueas River) is a river in the Indonesian part of Borneo island, at the geographic center of Maritime Southeast Asia. At 1,143 kilometers (710 mi) in length, it is the longest river of Indonesia and one of the world's longest island rivers. It originates in the Müller mountain range at the center of the island and flows west into the South China Sea creating an extended marshy delta. The delta is located west-southwest of Pontianak, the capital of West Kalimantan province. This Kapuas River should be distinguished from another Kapuas River, which starts on the other side of the same mountain range in central Borneo, but flows to the south, merging with the Barito River and discharging into the Java Sea.

Geography and hydrology

The river is 1,143 km (710 mi) long and up to 700 m (2,300 ft) wide at its delta; with a total area of 98,749 km², the river basin covers more than 67% of West Kalimantan. The discharge rate varies through the year, averaging around 6,000–7,000 m³/s at the delta and 2,000 m³/s upstream, at the confluence of the Tawang River. The discharge peaks during the rainy seasons in April and November, during which the water level may rise by 10–12 m overnight, overflowing river banks and flooding the nearby areas.

Kapuas River (Barito River)

The Kapuas River (or Kapueas) is a river in the Indonesian part of Borneo island. It originates in the Müller Mountain Range at the center of the island and flows south until merging with the Barito River and discharging into the Java Sea. It should be distinguished from another Kapuas River, which starts on the other side of the same mountain range in central Borneo, but flows to the west and empties to the South China Sea.

The river is about 600 km (370 mi) long and up to 6 m (20 ft) deep. It flows through marshy region rich in tropical forests, nearly parallel to the Barito River, and merges with the latter about 60 km from the Java Sea coast, within the town of Kualakapuas (lit. mouth of Kapuas in Indonesian). Between 1880 and 1890, a 30 km long canal was dug by the Dutch colonizers between the Kapuas and Barito river for agricultural purposes. The Kapuas River is narrow (about 50 m) and very winding in its upper stream. It straightens and widens up to 450 m in its lower reaches. There, it contains several elongated islands (shorter than 2 km). Its discharge rate varies through the year reaching the maximum in the peak of rainy seasons in April and November. The river is navigable up to 420 km from the mouth. Significant deposits of coal and gold were discovered upstream. Because of the lack of infrastructure, the gold is mined mostly by primitive methods, with only one commercial mine on the river, and the coal is not explored yet. Several bridges cross the Kapuas River. One of them, located near the village Lungku Layang, Timpah (Indonesian: Kecamatan Timpah), Kapuas District (Indonesian: Kabupaten Kapuas), Central Kalimantan, collapsed on 3 April 2009 killing one and injuring 6 people working under the bridge.