Erosion. Citarum River Basin is divided into 19 watershed areas with erosion levels ranging from extremely low to extremely high categories.  The worst erosion occurrence is found in Citarum watershed with an annual erosion level of 592 tons per hectare.

Landslides usually happen in a slope of more than 2 m high and an inclination of 50%. Farmers in upper Citarum regions still prefer to grow vegetable plants of a short crop cycle. This practice prevents a speedy water absorption into the ground as the plants do not have prop roots which are capable of protecting the soil from erosion.

Erosion Rate in the upper Citarum area is higher than the level in the middle and lower Citarum. The high erosion level at the upper part of Citarum produces sediments which are carried away by the stream to lower areas.

Erosion Rate in downstream Citarum area is considered to be lower than the level at upper Citarum. Sub-watershed area of Cikao has a high erosivity level covering almost 6% of the total sub-watershed area (22,072 ha). Cikao sub-watershed, which is located in Karawang and Purwakarta Districts, is a hilly area which makes it prone to land degradation that triggers a high erosion level.  

Sedimentation. A rising rate of erosion has contributed to the deposition of sediments into riverbeds, dams and even to water system infrastructure. According to the 12 January 2010 report made by the secretariat for Citarum Basin water resources management coordination the sedimentation rate in Saguling Dam reached 8.2 million m3 a year (in a 1988-2009 period), Cirata Dam 6.4 million m3 a year (1988-2008) and Jatiluhur Dam 1.6 million m3 a year (1987-1997). These high sedimentation rates would speedily reduce the dams’ capacities and shorten their operational lifespan.

Sediments deposited in lower Citarum area are contributed by erosion materials from upper region.

Bandung Groundwater Basin has been sinking. In a period of 2000 to 2002 the land area subsided by 7 cm to 52 cm in depth at a rate of 2 to 18 mm per month. This was in line with the rapid development in industrial and public settlement expansion. Therefore, the most severe decrease in groundwater level was recorded in industrial areas such as Cimahi (around Leuwigajah), Batujajar, Dayeuhkolot, Rancaekek-Cicalengka, Ujungberung, Cicaheum, and Kiaracondong.  In 2008 the demand for water for domestic, industrial and irrigation purposes was estimated to reach a total of 17.6 billion m3 per year. This demand for water is expected to rise at a rate of 1 to 1.7 % a year and only a half of the total demand can be fulfilled by a surface water supply, while the rest will be covered by groundwater sources.  

Groundwater Exploitation. Within Bandung area, 90% of the total population and 98% of the industrial activities rely on groundwater sources. Groundwater exploitation, however, leads to land subsidence and decreasing groundwater level especially in Bandung Basin area. The groundwater level at a certain same location has reportedly dropped by 5 m in depth per year with a total accumulative decrease of 85 m in depth over the last 80 years. Today, a manufacturer needs to drill up to 150 m deep into the ground to access groundwater. Citarum River Basin is home to about 1,423 manufacturers. The expansion of manufacturing industry especially in Bandung area and lower Citarum leads to an increase in water consumption. Inadequate supply of surface water sources raises the practice of overexploitation of groundwater by the industry.

Population growth and rapid expansion in infrastructure and facility developments in Citarum River Basin affects the environmental condition, resulting in environmental quality deterioration, environmental degradation and destruction, natural resources depletion and land use conversion.

Land Use Conversion over a period of ten years (2002-2012) was materialized in the land use expansion for housing to 83.35 km2, fish pond 40.67 km2, farm 28.24 km2, industrial activities 24.74 km2, garden/plantation 21.43km2 and bush 13.02 km2. While land use for forest was reduced to 131.18 km2, irrigated rice fields 38.56 km2, mangrove forest 27.97 km2, rainfed rice fields 5.85 km2,  salt ponds 4.11 km2, swamp areas 2.08 km2 and vacant lands 1.68 km2.

Industrial wastewater does not only flow into Citarum River but it flows further into drainage channels that pass through rice fields and housing areas.

Samples of water from 20 location points to asses Citarum water quality during a dry season indicated heavy contamination. The result of water quality test in river streams and dams during a dry season confirmed a heavy contamination in Citarik , downstream Cikeruh,  upstream Cipamokolan, downstream Cipamokolan, Upstream Cikapundung, Middle Cikapundung, Cisangkuy, Saguling Dam outlet, Cirata Dam, downstream Ciasem, upstream Cipunagara, Middle Cipunagara, downstream Cipunagara. A test result confirming moderate contamination in river stream was found in water sample from Cibeet, Middle Ciasem, Situ Cisanti, Cirasea and upstream Cikeruh. While water samples from upstream Ciasem and Cikao river stream indicated light contamination.

Test results of Citarum water quality during a wet season showed an indication of moderate and light contamination. The water bodies whose sample confirming moderate pollution consist of Cirasea,  Citarik,  downstream Cikeruh,  upstream Cipamokolan,  upstream Cipamokolan,  upstream Cikapundung, middle Cikapundung,  Cisangkuy,  Saguling Dam outlet,  Cirata Dam,  Cikao,  Cibeet, downstream Ciasem, middle Ciasem, middle Cipunagara and downstream Cipunagara. While samples with a light pollution indication were from Situ Cisanti, upstream Cikeruh, upstream Ciasem and upstream Cipunagara.

Major flooding in Balleendah – Dayeuhkolot  areas in December  2013.

Flooding was recorded to have occurred in 22 incidents between 2011 and 2013 in some areas in Bandung with water levels reaching 40 to 80 cm. Areas that have been frequently hit by floods throughout a rainy season every year are Dayeuhkolot, Baleendah and Bojongsoang with 6, 8 and  3 incidents respectively.  

The worst impact of floods in the region was recorded on 13 February 2012 with 15,492 people affected and 345 others took refuge in Baleendah Sub-district, 13,783 affected and 215 took refuge in Dayeuhkolot Sub-district, 9,208 affected and 150 took refuge in Bojongsoang Sub-district.

Landslides were recorded to have occurred in 25 incidents in 2013, affecting various areas in West Java Province, including those located within Citarum River Basin namely the areas in Purwakarta, West Bandung and Cianjur Districts. Areas frequently hit by landslides in West Bandung District are Rongga, Parongpong, Gununghalu, Cililin, Cipongkor and Ngamprah Sub-districts. Sub-district areas prone to landslides in Cimahi City and Purwakarta District are Pasir Jambu (Cimahi City) and Bojong (Purwakarta District).

Citarum River was declared as a strategic river in Indonesia through a Presidential Decree Number 12 in the year 2012 on River Basin Territories. Citarum River Basin is a multi-provincial river basin whose management is carried out with respect to meet the raw water need of the capital of the Republic of Indonesia.

Citarum’s potential of water sources amounts to a total of 13 billion m3 a year. Of the total potential, the water sources that have been exploited amounted to 7.5 billion m3 a year (57.9% of the total) while the rest of 5.45 billion m3 a year (42.1%) has remained unexploited.  

Two National Parks, namely Mount Gede Pangrango (15,000 ha) and Mount Halimun (40,000 ha) National Parks, are located in Citarum River Basin. Mount Halimun National Park is one of the remaining tropical rainforests in the Island of Java, while Mount Gede Pangrango National Park with its thick mountainous vegetations is one of Indonesia primary rainforest areas. Mount Gede area is home to various springs whose streams, including Citarum River, travel to the Bay of Jakarta and empty into the Java Sea.

Curug Weir, is one of the constructions built to separate and distribute Citarum’s water through Tarum Canal for the provisions of raw water supply, industrial productions and agricultural irrigation.

Water Sources. Citarum River Basin provides raw water supply for drinking water services for domestic and industrial purposes within Bandung, Cimahi, Cianjur, Purwakarta, Bekasi, Karawang, and Jakarta areas. Jakarta’s demand for raw water of 16.1 m3 per second is supplied by Bekasi River and West Tarum Canal.

Jatiluhur Dam is one of the three large dams in Citarum River with a function to provide irrigation water and to generate hydroelectric power.

Citarum Dam. Citarum River Basin has 5 (five) dams including 3 (three) dams which operate hydropower stations (PLTA) namely: Saguling Hydropower Plant with a capacity of 750 MW, Cirata Hydropower Plant with a capacity of 1,000 MW, and Ir. H. Djuanda Hydropower Plant or popularly known as Jatiluhur Hydropower Plant with a capacity of 187.5 MW. Other dams are Cileunca and Cipanjuang Dams.

Citarum is the longest and largest river in West Java Province with 297 km in length. The stream of the river, which almost divides West Java into two areas, originates in a spring at Mount Wayang (to the south of Bandung City), travels to the north, runs through Bandung Basin and empties into the Java Sea.

The word “Citarum” comes from two words, that is, Ci and Tarum. Ci or Cai in Sundanese language means water. While the word Tarum is a kind of flowering plant (Indigofera) which is used as a natural indigo (purple) dye on traditional cloths.

Tarumanegara is the oldest and largest Hindu Kingdom in West Java. According to historical records in the fifth century Jayashingawarman first built a small village by the edge of the Citarum River and then it gradually expanded to be a large kingdom, that is, Tarumanegara Kingdom.

Citarum is an ancient river. Its headwater is located in Mount Wayang in Bandung District (1,700 m above sea level) and the stream passes through the base of Bandung Basin, flows further into Saguling Dam until it empties into the North Coast of Java Island, or to be precise, in Karawang District.

Bandung Basin is surrounded by volcanoes with heights between 650 m and  2000 m above sea level.

Citarum runs through Bandung Basin. Bandung Basin is surrounded by volcanoes with heights between 650 m and 2,000 m above sea level. Around 105,000 years ago Citarum water was pooled by a spectacular eruption unleashed by Mount Sunda and then it led to the formation of ancient Lake Bandung. As time passed, surface water level gradually increased and it is predicted that 36,000 years ago the level once peaked at 725 m above sea level. The eruption materials of Mount Tangkupanparahu, the successor of Mount Sunda, spilled over to the south approaching a location near Citarum in an area today called Curug Jompong. The materials then filled the surrounding valleys which led to the division of the giant ancient lake into two, that is, the west and east Lake Bandung.

Curug Jompong is believed to be the place where the wall of ancient Lake Bandung collapsed. This place used to be one of tourist destinations.

Curug Jompong. Evolutive developments and active river streams led to a formation of a fault and a land collapse in some areas. Subsequently, since 16,000 years ago water in the two ancient lakes started to recede. The leak location of the ancient Lake Bandung was in Curug Jompong.

Ancient Animal Fossils, including Elephant (Elephas Maximus), Rhino (Rhinocerus Sondaicus) and Tapir (Tapirus Indicus) and the teeth of hippo (Hippopotamus), were unearthed in Rancamalang, Cipeundeuy and Bandung Basin area. This proves that the areas around ancient Lake Bandung used to be inhabited by ancient animals.

Floods, especially within Bandung area, have been a frequent occurrence since a long time ago and are attributable to geological and topographical factors. The shape of Bandung Basin formation resembles a bowl as the basin is actually the remains of the drained ancient Lake Bandung, making the area almost always hit by floods especially during a wet season.  This condition led to an action taken by the then Bandung District Head R.A Wiranatakusumah II (1794-1829) to move the district capital from Krapyak to an area in the middle of Bandung District (today Bandung city center area).

The 1945 Indonesian Independence Proclamation Texts were composed in a Citarum riverside house in Rengasdengklok, Karawang District. The house belonged to an Indonesian Chinese named Djiaw Kie Siong.

Jiwa Temple, one of the temples in Batujaya Temple complex located in Karawang District

Batujaya Hindu Temple complex is situated in downstream Citarum region about 500 m from the main stream which branches off into 3 streams, that is, Bungin, Balukluk, and Muara Gembong Rivers before emptying into the Java Sea. It is estimated that the temple complex was built between the first and third century. The temples, which served as houses to worship, are a proof of the process of acceptance of Hinduism and Buddhism by the ancient Sundanese communities in West Java.

Citarum River originates in Situ Cisanti located at the foot of Mount Wayang, which lies to the south of the city of Bandung, and travels to the north until it empties into the Java Sea.

At about 297 km in length, the Citarum is the longest and largest river in West Java Province. The river plays a critical role in the social and economic life of people in West Java and the capital Jakarta. The river provides water sources for raw water supply, agricultural irrigation, fisheries, hydropower generations to supply electricity in Java and Bali Islands as well as industrial productions.   

Over the last twenty years the environmental condition and water quality along Citarum drainage area have significantly decreased. A rapid urbanization process as a consequence of an ever progressive development goes in line with an industrial expansion, a high population growth, an expansion of public settlement and land conversions for development. A great deal of negative impacts is the accumulative product of the imbalance between robust economic developments and environmental protections.

Almost in every rainy season floods threaten various areas in West Java. The river water pollution due to industrial and agricultural production has hit a dangerous level, threatening public health and livelihoods. The complexity of issues faced by Citarum River Basin presents a challenge to a collective rehabilitation and management effort to make a better Citarum.