Central Java, Opak River

Opak River


Opak River is a river that flows from the lower slopes of Mount Merapi and passes to the east the location of Yogyakarta and west of Kota Gede.

It also passes the historical locations of Plered, Karta, and Imogiri before draining into the Indian Ocean in the southern part of Bantul.

The river basin that it lies in is significant as the aquifier is in a heavily populated part of Java [1]

Central Java, Serayu River

Serayu River

Click to Enlarge !


With its source in the highlands of Mount Slamet on the Dieng plateau, the picturesque Serayu river flows rapidly across five districts in Central Java to empty out in the Indian Ocean, south of Java, near the town of Cilacap.

Flowing down from an altitude of 500 meters above sea level , Sungai Serayu covers  a length of  30 km with a width  of around 12 meters,  passing the five districts of: Wonosobo, Purbalingga, Banjarnegara, Banyumas and Cilacap.

Providing a backdrop of steeply sloping mountains and green rice paddies, the Serayu offers challenging rafting tracks and thrills for seekers of an adrenaline rush.
Aside from its swift moving rapids, there are winding river paths with rocks of all sizes scattered randomly in your path, making for a very challenging and exciting adventure rafting along this river.

Rafting on the Serayu starts at the Tunggoro village, Sigaluh sub-District, in theBanjarnegara District in  Central Java. The route to reach this location is not difficult to remember being located on the side of the main road linking the cities of Wonosobo and Banjarnegara.

In 1997, the Serayu was chosen as the course for the Indonesian National Rafting Competition.
 And it was from this time on that the public became more aware of this river, which flows right through their midst, that possesses such unique and challenging terrain.  The Serayu today is one of Indonesia’s most popular rafting tracks, that is very reliable and well worth considering for those who love a sports challenge.

Serayu offers two crossing trips, each of about 12 km. The distance takes between 2 hours to 2.5 hours.

With an approximate width of between 12-12.5 meters, rafting on this river enters into the categories 3 and 4 in rafting terms. Aside from the excitement and challenge of navigating through this river there is also amazing, natural scenery on either side of the river. Another plus to this site is that its water currents and levels are not affected by the rain or lack there of, making the Serayu a suitable all year round rafting destination regardless of season.

Professional rafting operators here offer a variety of excursion packages for water sports activities. The cost per rental package usually comes complete with rafting equipment, including inflatable boats, life jackets, guide services, food, and insurance. Besides rafting, operators typically also provide packages for other activities such as outbound training, paint ball games, and outdoor camping. Food stalls and home-stays at local homes can also be found around this area, which will add to the cultural aspect of your visit to Central Java.

Fishing is another sport to enjoy. In Serayu are found abundant catfish, nila and shrimps.

In addition to being an excellent rafting  and fishing location, Sungai Serayu has other tourist attractions. There are several activities and cultural attractions that can be enjoyed at certain times of the year, for example the Grebeg Suro and the Serayu Festival . You can read more about these in the “TO DO” section.

Sungai Serayu is the lifeblood of the five districts in its path and the river’s waters are of very good quality, healthy, and clean. This means that the river which covers approximately 360,639 hectares is also a very useful source of irrigation for the surrounding farmland.

To Stay

If you opt to stay directly in the Sungai Serayu area,  lodging options here are private homestays. This will be at the homes of residents in this area. You will be able to get information on these from any of the locals or from the rafting operators.

If you want to stay at Banjarnegara, which is not directly in the river area, the following list of lodgings can be of assistance:

Hotel  A

Show More


Be careful when wading in the Serayu river.  At the start, the water flow may not appear too challenging but after about one kilometer, the current will have increased so much so that most of the time there isn’t even a need to paddle to continue moving through the water, as the current will be strong enough to push you along. Keep an open eye for the scattered boulders and rocks throug

Show More

Get There

The Serayu region can be primarily reached by taking the train from Jakarta or Yogyakarta to Purwokerto train station. This town is located near the foothills of GunungS lamet, where the river itself is located.  From here you can take a taxi or chartered car to get to the rafting location.If you already know the exact location of the rafting spot you want to visit, there is a lot of reliable

Show More

To Do

The rapid flow of Sungai Serayu and its challenging terrain makes this river a natural tourist destination, especially attractive for river rafting fans. Serayu has a rafting grade of 3-4. The surrounding natural scenery is also beautiful and another bonus adventure is trekking and exploring the off thebeaten paths surrounding Serayu.There are also several food stalls, locker room facilities, and

East Java, Brantas River

Brantas River


The Brantas is the longest river in East Java, Indonesia. It drains an area over 11,000km² from the southern slope of Mount Kawi-Kelud-Butak, Mount Wilis, and the northern slopes of Mount Liman-Limas, Mount Welirang, and Mount Anjasmoro.[1] Its course is semi-circular or spiral in shape: at its source the river heads southeast, but gradually curves south, then southwest, then west, then north, and finally it flows generally eastward at the point where it branches off to become Mas and Porong Rivers.


King Mpu Sindok moved his kingdom from Mataram Kingdom in Central Java to a new location on this river at circa 950 A.D. Possibly (only one of a number of reasons given) due to a Mount Merapi volcanic eruption, he had to leave his kingdom to this new safe place near present city of Madiun.

Cities and regencies on Brantas River

  • Batu
  • Malang Regency
  • Malang
  • Blitar Regency
  • Blitar
  • Tulungagung Regency
  • Kediri Regency
  • Kediri
  • Nganjuk Regency
  • Jombang Regency
  • Mojokerto Regency
  • Mojokerto

East Java, Solo River

Solo Bengawan River

Click to Enlarge !


Bengawan Solo River (alternatively, Solo River, with Bengawan being an Old Javanese word for river) is the longest river in the Indonesian island of Java, it is approximately 600 km in length. Apart from its importance as a watercourse to the inhabitants and farmlands of the eastern and northern parts of the island, it is a renowned region in paleoanthropology circles. Many discoveries of early hominid remains have been made at several sites in its valleys, especially at Sangiran, including that of the first early human fossil found outside of Europe, the so-called “Java Man” skull.

Bengawan Solo was the crash site of Garuda Indonesia Flight 421.[2]

Solo River (or Bengawan Solo) has two sources: from the volcano of Mount Lawu, on the border between Central Java and East Java and from Kidul Mountain. In ancient time, the rise of Indo-Australian Plate redirected its stream northward. Sadeng Beach, located in Special Region of Yogyakarta, has been known as mouth of ancient Solo River, which flew southward in antiquity.

It passes through the major city of Surakarta (called Solo by the local inhabitants). An important early tributary to the Solo river is the Dengkeng River, which has its source in Mount Merapi.[3] After passing through Solo, the river flows northward around Mount Lawu, and then turn eastward into East Java in the Ngawi regency.

After Ngawi the river turns northward again, forming the boundary between Blora Regency of Central Java and Bojonegoro regency of East Java. From the town of Cepu in Blora, the river turns eastward and passes through Bojonegoro regency’s capital city. From there, it continues eastward through the Lamongan and Gresik Regencies. The last part of the river’s basin (roughly starting from Bojonegoro regency) is mostly flat land.[4]

Bengawan Solo’s delta is located near the town of Sidayu in Gresik regency. The present delta is redirected by a human made canal.[4] The original delta flowed into the Madura Strait,[4] but in 1890 a 12 km canal was made by the Dutch East Indies authority to redirect the Solo River into Java Sea.[4][5] This was done to prevent sedimentation of mud from filling the Madura Strait and thereby preventing sea access to the important port city of Surabaya.[4]

The Solo river delta has a huge mud sedimentation flow that deposited 17 million tonnes of mud per year. This sedimentation in the delta form a cape, which has average longitudinal growth of 70 m per year.[5] This delta is known as Ujung Pangkah (Pangkah Cape).


Solo river was part of massive river system that once existed in Sundaland. This drainage of the river system consisted of major river in present-day Sumatra and Borneo, such as Asahan river, Musi river and Kapuas river. The river system disappeared when Sundaland was submerged after sea level rise following the last Ice Age.[6]

The river played important part in Javanese history. Its drainage basin is an important agricultural area, dominated by rice farming. The river transported fertile volcanic soil downstream, replenishing the soil. It also provided link between Javanese port cities in the northern coast and the rice-growing hinterlands, with shallow vessels transporting rice to he ports to be sold.[7] This rice is Java’s main commodity that was traded as part of the Spice trade.

Following acquisition of much of Java by the Dutch colonial governmental, various cash crops was introduced to be planted across the river basin, such as coffee, sugar and cotton. (see Cultivation System).

By the last years of 19th century, river sedimentation in its original delta in Madura Strait started to disrupt vessels traffic in port of Surabaya. The Dutch colonial government decided to divert the river flow away from the shipping lane into Java Sea. They built a canal in the river’s delta in 1890s which still alter the river until this day.[8]

In 1891, Dutch paleoanthropologist Eugène Dubois discovered remains of what he described as “a species in between humans and apes”. He called his finds Pithecanthropus erectus (“ape-human that stands upright”) or Java Man. Today, they are classified as Homo erectus (“human that stands upright”).[9] These were the first specimens of early hominid remains to be found outside of Africa or Europe.

Resource management

Brantas River Public Corporation or Perum Jasa Tirta I (PJT1) is responsible for managing the water resources of Brantas and Bengawan Solo river basins in Indonesia.[10] It is a centralised effort to:

  • conserve the water resource quality and quantity in the Bengawan Solo and Brantas River basins
  • flood control
  • manage hydroelectric and other infrastructures along those rivers.

Prior to the centralised management efforts, there were reports of pollution along the Bengawan Solo .[11]

Media depiction

Inspired by the river, Gesang Martohartono created a song named after the river. Bengawan Solo became a popular folk song in Indonesia.

West Java, Citarum River

Citarum River


Go away !  hazardous waste

Citarum (Sundanese: Walungan Citarum) is the longest and largest river in West Java, Indonesia.[1] The river is also the third longest river in Java after Bengawan Solo and Brantas. It has an important role in the life of the people of West Java, as it is used to support agriculture, water supply, fishery, industry, sewerage, electricity etc.

In Indonesian history the river is linked with 4th century Tarumanagara kingdom, as the kingdom and the river shared the same etymology, derived from the word “Tarum” (Sundanese for indigo plant). The earlier 4th century BCE prehistoric Buni clay pottery-making culture flourished near the river’s mouth. According to stone inscriptions and Chinese sources, also the archaeological sites such as Batujaya and Cibuaya, suggested that the human habitation and civilization has flourished in and around the river estuaries and river valley as early as 4th century and even earlier.

Hydroelectric and irrigation dams

There are three hydroelectric powerplant dams installed along this river; Saguling, Cirata, and Ir. H. Djuanda (Jatiluhur) hydroelectric powerplants, all supplying the electricity for Bandung and Greater Jakarta area. The waters from these three dams are also used to irrigate vast rice paddies in Karawang and Bekasi area, making northern West Java lowlands as one of the most productive rice farming area in Indonesia.[2]

The Jatiluhur Dam with a 3 billion cubic meter storage capacity has the largest reservoir in Indonesia.[3] The river makes up around 80 per cent of the surface water available to the people who use it and pollution has affected agriculture so much, that farmers have sold their rice paddies for half their normal price.[4]


The river is heavily polluted by human activity; about five million people live in the basin of the river.[5][6] Textile factories in Bandung and Cimahi were major toxic waste contributors.[7] More than 2,000 industries contaminate 5,020 sq miles of the river with lead, mercury, arsenic and other toxins.[8]

On December 5, 2008, the Asian Development Bank approved a $500 million loan for cleaning up the river, calling it the world’s dirtiest.[9]


In November 2011, the river revitalization began, with an expected cost of Rp35 trillion ($4 billion) over a time frame of 15 years. The revitalization is occurring from Mount Wayang through 8 regencies and 3 cities for a distance of 180 kilometers . The target for the first 3 years is to pick up 10.5 million cubic meters of sedimentation.[10]

West Java, Ciliwung River

Ciliwung River

Click to Enlarge !


Ciliwung (variously written as Tjiliwong (Dutch)) is a 97 km long river in the western region of Java where it flows through two provinces, West Java and the special region of Jakarta. Ciliwung’ river estuary, now a part of a canal known as Kali Besar (“Big River”) was an important strategic point for trade in precolonial and colonial period and was instrumental in the founding of the port city of Jakarta.

Kali Besar was the main estuary of Ciliwung until the Dutch reorganized the watercourse of rivers around the area into canals. Today both Krukut and Ciliwung river flows to Kali Besar, and so Kali Besar in modern time is not the main estuary of Ciliwung any longer.



Ciliwung means “turbid water” in Sundanese.


Ciliwung is 97 km long with a catchment area of 476 km2. The Ciliwung river has its source at Mount Mandalawangi in Bogor Regency with the highest peak at 3,002 m. The river flows in a northern direction passing several active volcanoes, Mount Salak, Mount Kendeng, and Mount Halimun, crosses two main cities Bogor and Jakarta before finally flowing into the Java Sea through Jakarta Bay. The main tributaries in the upper catchment area are the Ciesek and Ciluar rivers with respective lengths 9.7 km and 21.0 km, with catchment areas of 27.15 km2 and 35.25 km2 respectively.

Ciliwung river basin has a narrow and elongated shape. The 17.2 km length of the upstream area has a very steep slope (0.08), The 25.4 km length in the middle-reach has a slope of 0.01 and the downstream, 55 km in length, has a flat slope of 0.0018. In general the geology of the upstream of Ciliwung river basin is dominated by Tuffaceous Breccia and older deposits lahar and lava. The middle-reach consists mainly of Quaternary period alluvial fans and volcanic rocks. The downstream area is dominated by alluvial and beach ridge deposits.

Mean rainfall reaches 3,125 mm, with mean annual discharge of 16 m3/s as measured at Ciliwung Ratujaya observation station (231 km2). With such topographical, geological and hydrological features the Ciliwung river is often overflowing and inundating parts of Jakarta. The population along the Ciliwung river basin reaches 4.088 million (Census 2000) which can be regarded as the most densely populated area.[1]

Jakarta’s canal

The natural flow of Ciliwung was diverted into canals by the Dutch during the early settlement of Jakarta, then Batavia. Beginning in area that is now Istiqlal Mosque, Ciliwung was diverted into two canals, one flowing northwest and one flowing northeast.

The western branch flows along the canal of Jalan Veteran and then through the canal of Jalan Gajah Mada. This 2 km straight canal is known as Batang Hari canal, previously known as Molenvliet, which was dug in the 17th century. Formerly the water branches into two direction in Glodok, following the two course that is now Jalan Pancoran and Jalan Pinangsia Raya; today the water from Batang Hari canal was diverted east before Lindeteves Trade Center. Eventually the water ends up in Sunda Kelapa harbor after passing through the canals of Jakarta Old Town.

The eastern branch flows along the canal of Jalan Antara, passing the Gedung Kesenian Jakarta and then along the canal of Jalan Gunung Sahari. The water ends up in Ancol.

Initially a canal links the eastern and the western branches of Ciliwung. Today this canal, which is now located on the south side of Jalan Tol Pelabuhan, was filled with slum settlement due to careless planning after the independence period.

After the 1918 Jakarta’s big flood, a new canal, the Banjir canal (“flood canal”), was constructed in 1922 to divert the water of several rivers of Jakarta, which includes Ciliwung, Cideng, and Krukut. The flow of Ciliwung was diverted through the Manggarai floodgate, constructed at the point near Manggarai station. The water is diverted to the west of the city through Pasar Rumput, Dukuh Atas and going to northwest to Karet Kubur and continued to Tanah Abang, Tomang, Grogol, Pademangan, and ends at Muara Angke.

The New East Flood Canal has been opened since 2010, a 23 kilometers canal from Cipinang River to the east and then to the north of Java Sea as a quarter of a circle with 100 to 300 meters width.[2] On December 19, 2013 a contract to build water tunnel(s) to East Flood Canal from Ciliwung River with minimum capacity of 60 cubic meters per second has been signed by Public Works Ministry.[3] So, the floods in East Jakarta to the north and along the Ciliwung River will be eased.

Ciliwung-Cisadane tunnel

A coordination meeting on January 20, 2014 among the Ministry of Public Works, Ministry of Environment, Jakarta Governor, Bogor Mayor, Bogor Regent and Ciliwung-Cisadane Rivers Control Office agreed to build 1.2 kilometers tunnel from Ciliwung to Cisadane River with capacity 200 cubic meters per second to ease Ciliwung debit when Cisadane is not in flood condition.[4]


The Ciliwung River Basin has been populated at least since the 4th century. In the Bogor area (Upper Ciliwung) in the past were found two kingdoms; Tarumanegara (4th-5th Century) with its King Purnawarman and Padjajaran (15th-16th Century) with its King Sri Baduga. The existence of these Kingdoms is found from ancient inscriptions at Ciaruteun (Tarumanagara) and Batutulis (Padjajaran).[1]

Main article: History of Jakarta

The mouth of Ciliwung was instrumental in the founding of the city of Jakarta. The mouth of Ciliwung was a port city for the Kingdom of Sunda, within the sphere of Srivijaya maritime empire.[5] During the arrival of Europeans period, the mouth was used as port city by the Portuguese (1522),[6] Sultanate of Banten (1527)[6] and the Dutch (1619) who constructed a fort at the east bank of the estuary and founded Batavia, the largest city and the capital of the East Indies Empire, until the city was transformed into Jakarta after the independence of Indonesia.

With the establishment of Batavia in the 17th century, the Dutch diverted Ciliwung into canals, following a typical Dutch city pattern. The largest canal which flows through the middle of the city was named Kali Besar or Dutch Grote Rivier (“Big River”). Small boats sailed along Ciliwung to transport goods from warehouses close to Kali Besar to ships anchored at the port.[7]

In the middle of 1630, the canals of Batavia experienced sedimentation. In order to deal with this, an 800 m long ditch was constructed to the sea that was routinely dredged to ease the flow of water. The length of the ditch increased to 1,350 m (1827) from the mouth of the river due to accumulation of sand and mud and what more with the earthquake in January 1699 [7]

Ciliwung tributary that empties into the ocean was used for ship entrance into the castle from the canals to Waterpoort. The Molenvliet, a canal, was constructed to the south of Grote Rivier, mainly for water transportation used by various industries along the side of the river. Back then, Ciliwung River’s waters were used by the citizens for drinking water. In 1689, the river water was not yet polluted and could be used for drinking water. The earthquake, which occurred in January 1699, caused the increase in sedimentation level. Heaps of mud and sand accumulated in the ditch that was dredged to ease the flow of the water to and from the river.[7]

In 1740, the river water was considered unhealthy because of rubbish and the waste from the Binnen Hospital discharged into the river. Many patients suffered from dysentery and cholera. The unhygienic drinking water caused high death rates among the Batavia citizens. On the other hand, most of the Chinese who drank tea rarely got sick. Aware of this, many Dutch people ate tea leaves to stay healthy, but obviously this attempt did not succeed. By the end of the 18th century, Doctor Thunberg still prescribed tea leaves instead of boiled water. It was still unknown at that time that bacteria can be killed by boiling water until boiling point. The Dutch still drank water from Ciliwung through the 19th century. Water from Ciliwung was initially stored in a reservoir (waterplaats or aquada) near Fort Jacatra, north of the city. Later the reservoir was transferred to the sides of Molenvliet in Glodok area. The reservoir contains wooden water outlets which pour water from the height of about 10 feet. The local people knows the area around this reservoir as Pancuran. Back then when Molenvliet was deep enough for boats to sail, annual Peh Cun or Dragon Boat festival were held in the river.[7]

The part of Ciliwung that flows straight from Harmoni to the north used to be a private river with toll payments for those who wanted to pass through it. This river was named Molenvliet and it was built by the Dutch by Kapitein der Chinezen (head of the Chinese in Betawi), Phoa Beng Gan known as Beng Gan. In 1648, Beng Gan received permission from the Company to build this river and collected toll payments from sampans that passed through. In 1654, it was taken over by the Company for 1.000 real.

Today, the river water is murky once it reaches Jakarta because the area of its flow is a disposal area. As a result, the river is growing shallower and the flow slower.[7]


The Ciliwung River flows through two provinces, West Java and the Special Region of Jakarta. Two main races dominate the region namely, the Sundanese (West Java) in southern Ciliwung and Orang Betawi (Jakarta) in northern Ciliwung.

Culture in the Bogor area is mainly Sundanese, such as can be observed from traditional dances, the Ketuk Tilu or the Jaipongan which is modern, sensual and full of spirit. Specific Sundanese music can be observed from the Degung, Calung, Angklung and Kecapi suling.

Culture of Jakarta can be seen in the Yapong dance and Gambang kromong as well as Kroncong music can still be found at Tugu, north of Jakarta. Also famous is a humorous play, the Lenong, using a special Betawi dialect.


Main article: Flooding in Jakarta

The section of Ciliwung in Jakarta is heavily polluted. Informal settlements or slums flourished on the banks of Ciliwung, increasing the amount of waste and reducing the surface area of the river. Some canals was completely blocked by slums and people created informal gardens inside by drying the canal. Water maintenance and ecological awareness is minimal. Flooding is a problem of Ciliwung. With many of the original forest converted into settlements around Puncak area, the flooding got worsen each year.