Rajang River

The Rajang River (Malay: Sungai/Batang Rajang) is a river in Sarawak, northwestern Borneo, Malaysia. It is one of the important rivers in the region, stretching about 565 km (351 mi) long. This makes it the seventh-longest river on the island of Borneo and the longest river in Malaysia.

The river starts in the Iran Mountains and flows through the town of Kapit before emptying into the South China Sea. Many smaller rivers, called tributaries, join the Rajang River along its path, including the Katibas River, Ngemah River, Iran River, Pila River, Balleh River, Bangkit River, and the Kanowit River.

One of the biggest projects near the Rajang River is Malaysia's largest and tallest hydroelectric dam, the Bakun Hydro Electric Dam, which is built on the Balui River, a smaller river that feeds into the Rajang. This dam helps provide power to many people in the area.

Etymology

In Sarawakian Malay, big rivers are called Batang, meaning "trunk" or "tree". This is because the river starts from smaller streams called Sungai, meaning "river", and then flows out into the sea. The Rajang River is called Batang Rajang in Malay.

Far up the river, places are called "Ulu" or "Hulu", meaning "up the river". Areas too small to be towns are named "Nanga" in the Iban language, meaning "longhouse". Some examples are Nanga Ngemah, Nanga Dap, and Nanga Poi. Some places use the word "Rumah", meaning "house", followed by a person's name. The Orang Ulu people use the word "Long" to name spots where small rivers meet the big river.

Course

The Rajang River is the longest river in Malaysia. It starts in the Nieuwenhuis mountains, where it forms a border between Malaysia and Indonesia. These mountains receive lots of rain, which feeds the river's water. The river flows from northeast to southwest.

Many different people groups live along the Rajang River, such as the Punan Bah, Kayan people, Kenyah people, and Iban people. As the river continues, it grows wider and deeper. Near the town of Kapit, the river changes direction and flows from east to west. Kapit is an important town where people of different backgrounds live.

Other towns along the river include Song, Kanowit, and the largest town, Sibu. Sibu is a major center for business, culture, and education. The river ends near the town of Rajang, close to the South China Sea.

History

The Rajang River area had few people living there in the 1800s when it was part of the Bruneian Empire. Different groups of people lived along the river, trading with others from Brunei. Later, new groups moved into the area, which caused some conflicts.

In the late 1800s, leaders built forts along the river to bring peace. People from China also moved in and settled near these forts. One important fort, Fort Vyner, was built in 1884, and the town of Belaga grew to become an important place for government and trade.

During this time, people grew crops like rubber and pepper, and some continued to live by gathering items from the jungle to sell. In 1973, special safety measures were put in place to protect the area from unrest. Later, a large dam was built, which changed where some people lived.

Wildlife

Mammals

In 2004, scientists found thirty kinds of mammals in the Rajang River area. The river's mouth is a special spot where dolphins can sometimes be seen. Some mammals, like the gibbon, langurs, black giant squirrel, slow loris, and tarsier, are protected by law. Other animals such as civets, otters, bats, treeshrew, and primates are also protected. Local people often hunt wild pigs and deer.

Birds

The 2004 study counted 122 kinds of birds in the Rajang River area. Near the river mouth, 21 bird species were found, while 96 species lived in the Hose Mountains, and 88 species were in Lanjak Entimau inside Sarawak. One special bird only found here is the Dusky munia, which lives in rice fields. Common birds include the Pacific swallow, Little spiderhunter, and Asian glossy starling. Some birds, like eagles, egrets, kingfishers, and woodpeckers, are protected, as well as seven birds including hornbills and pheasants.

Fish

In 2005, scientists recorded 164 kinds of fish in the Rajang River area. Two popular local fish are the Empurau (Tor tambroides) and Semah (Tor douronensis). The Empurau fish still breed near the upper parts of the Rajang River, such as the Balleh River and close to the Bakun Dam.

Economy

The Rajang River helps people make a living in many ways. In the upper part of the river, people cut down trees like Ramin, plywood, Kapur, Meranti, Keruing, and Belian to sell. In the middle part, people grow rice. Long ago, in the 1960s and 1970s, people traded Engkabang fruits, also called illipe nuts, especially in a place called Sibu. These fruits are also food for fish in the river. People also grow rubber, pepper, vegetables, and keep poultry.

Trade

The Rajang Port Authority looks after trade along the river's five river ports. In 2012, the authority made RM 30.1 million but moved less cargo than the year before. The ports are:

Tanjung Manis (30 km, for logs and timber)
Sarikei (49 km, for farm products and goods)
Bintangor (66 km)
Sibu (113 km, for timber and farm products)
Sungai Merah (116 km, for fuel oil)

Tourism

Tourists used to take boat trips on the Rajang River between Sibu and a resort in Kapit, but these trips stopped because of problems. In 2017, visits to traditional homes along the river were promoted. Crocodiles that live near the river became a symbol for the event.

Transportation

The town of Sibu can be reached by large ships for about 80 miles (130 km), and smaller boats can travel an extra 100 miles (160 km). Farther inland, only small canoes can be used. Speedboats and longboats are the main ways people travel between Kapit and Belaga. To go from above Belaga to the Balui River, longboats are needed. The Rajang River is also used to carry logs. During the rainy season, some inner areas can only be reached by boat. In towns closer to the sea, market traders sometimes have problems because of floods.

Water quality

Logging activities near the Rajang River have made the water look cloudy, especially in the main part of the river. A study done between May and December 2004 showed that the water was only about 4 cm to 5 cm clear. Some smaller parts of the river are still getting better after logging happened there 15 to 20 years ago, but one small river called the Penaan is not clean because people there use harmful chemicals to catch fish. The part of the river closer to the sea, from Lebaan to Selalang, is also considered not clean.

Floods

Floods near the coast of the Rajang River happen when the tide rises. Further inland, near a place called Sibu, floods happen when there is a lot of rain and the river cannot drain well because of dirt and sand built up in it. This is because people have built many things along the river upstream.

In September 2020, lots of rain in the areas where the river begins caused sudden floods in lower areas of Kapit, Song, Kanowit, and Sibu.

Logjams

In October 2010, heavy rain caused a big landslide that sent lots of logs and debris into the Balleh River and then into the Rajang River. This made it hard for people to travel along the river and hurt many fish. In August 2021, another logjam blocked the Rejang River and stopped water treatment plants in Sibu from working. Similar logjams happened in early 2017 and in March 2024 near the town of Song.