Chilivung

The length of the river, according to various estimates - 89 ^[1] or 117 km ^[2] , the basin area - from 347 ^[1] to 375 km² ^[2] . The river does not differ in significant width and depth. Chilivung's flow rate during the period of the annual maximum precipitation reaches 500 million m³ per year ^[1] .

The source of Chilivung is located in a mountainous region with the historical name Punchak , on the border of two districts ( kabupatenov ) of the West Java province - Bogor and Chiangjur , about 60 km from Jakarta (if you take it in a straight line). The first kilometers the river passes through an area full of stony drops and rapids . Then it flows through the territory of the cities of Bogor and Depok , mainly along the flat terrain. Below Bogor, Chilivung flows mainly in a highly urbanized landscape; the last kilometers are within the framework of the Special Capital District of Jakarta. Within the city, it serves as the border between the two municipalities of the Metropolitan District - South and East Jakarta . It flows into the Java Sea in the area of ​​the commercial port of Jakarta. It is the largest of 13 rivers flowing through the territory of the Indonesian capital ^{[2] [4]} .

The lower part of Chilivung, approximately from the geographical center of Jakarta to the confluence of the sea, passes along an artificially deepened channel, with banks reinforced with concrete masonry. Several channels are allocated from the river bed, designed to receive excess water in the rainy season to avoid flooding . This does not always give the proper effect; Chilivung’s spill contributes significantly to the floods that occur in Jakarta almost every year ^{[5] [6]} . In order to improve the situation, the authorities of Jakarta and the districts of West Java adjacent to the capital of the provinces agreed on a plan in January 2014 to build an additional system of hydraulic structures , in particular, two underground reservoirs and a tunnel more than 1.2 km long for the seasonal diversion of Chilivung waters to the Chisadan River, flowing to west of Chilivung and flowing into the Java Sea north of the Soekarno-Hatta International Airport ^{[7] [8]} .

The river flows either in urban or in extremely densely populated rural areas. It is estimated that in 2000, 4,088,000 people lived in the river basin ^[2] . Moreover, due to the general fast pace of urbanization of the island of Java, the floodplain of the river continues to be intensively built up, and the population of this area is growing rapidly ^[1] .

Already in the upper reaches, the river is heavily polluted due to the discharge of industrial and waste water . Within Jakarta, this pollution is becoming extremely high. According to estimates from 2004 to 2006 , about 107.6 tons of pollutants per hour, both organic and inorganic, got into the river. Three quarters of this amount accounted for Jakarta. The situation is aggravated by the fact that the poor population of Jakarta uses the river to dump all kinds of household waste and drain sewage ^[1] . Within the metropolitan area, the water in the river is muddy ^[4] .

Despite the exceptionally high level of pollution, a rather significant ichthyofauna remains in the river. Of the 33 species of fish that lived in this river, according to 1907 studies, currently 20 live in Chilivung ^[9] . Some of these species are of particular importance for the rural population living in the upper river, as an object of commercial and amateur fishing. First of all, it is a small catfish Hemibagrus nemurus , fish Tor soro from the genus of the Torah family of cyprinidae , a representative of the genus Puntius Puntius binotatus , the analysis of Rasbora aprotaenia , etc. In total, 187 species were described in the ichthyofauna of the river, including freshwater crab , shrimp, and others crustaceans . Invasive species, such as tilapia , are also found. The abundance of all species is currently very low and continues to decline ^[9] .

The Chilivung River was important as a transport artery during the initial penetration of the Netherlands East India Company into Java at the beginning of the 17th century . The first Dutch permanent possessions in Java were tied to this river: in particular, the first fort of the East India Company - Batavia, which became the center of the city of the same name in a short time, and later - the capital of Indonesia, Jakarta, was built in 1619 at the confluence of Chilivung in sea. The river was actively used by the Dutch both for transporting various goods on boats and as the main source of fresh water, which greatly facilitated their further development of the adjacent territories ^[4] .

One of the most dramatic episodes in the history of the Dutch colonization of Java - the siege of Batavia by the troops of Susukhunan Mataram Agung in 1629, is directly connected with Chilivung. Unable to storm the fortress, the Mataram troops first tried to block Chilivung, striving to deprive the besieged of drinking water, and having failed in this, they abundantly polluted the river with corpses and sewage. Pollution led to an outbreak of epidemics of cholera and dysentery , leading to great casualties both in the defending camp and among the besiegers (among the dead was Batavia's founder, Governor-General of the Netherlands East Indies, Jan Peterson Kun ). This venture did not help the Mataramians: even weakened by epidemics, the Dutch were able to keep the citadel and, a few days after the death of their commander, sent the Javanese to flight ^[10] .

With the growth of the city and population growth, pollution of the river with sewage began to affect more and more. By the 1740s, water pollution in Chilivung led to the spread of infectious diseases, especially cholera. However, water from the river was used for drinking raw until the middle of the 19th century . In 1827, the first canal was built to regulate the water level, which in previous decades decreased significantly due to siltation, which, in turn, was caused, among other things, by frequent earthquakes ). In the subsequent period, work was repeatedly carried out to deepen the channel and change its direction. During the XIX century and in the first half of the XX century , several reservoirs were built, filled with Chilivung waters ^[4] .

Currently, Chilivung has no transport significance, although boats can rise along it almost to the middle of the Capital District. This applies primarily to boating during the celebrations held by the local Chinese community ^[4] . Despite severe pollution, the river continues to be considered by the Jakarta authorities as a source of water ^[1] .