Pasanggrahan flooding due to bottlenecks

Bambang Nurbianto, The Jakarta Post, Jakarta

Pasanggrahan is one of the three major rivers in the capital causing the regular floods that plague the city. When the Cipinang River overflows it causes flooding in eastern Jakarta, while the Ciliwung River is responsible for floods in Central Jakarta. And Pasanggrahan River is to blame for flooding in the western part of the city.

Pasanggrahan River, which originates in Bogor regency, flows to the Java Sea through several subdistricts in South and West Jakarta, including Tanah Kusir, Bintaro, Pondok Pinang, Cipulir, Meruya, Kebon Jeruk, Kembangan, Kedoya and Pedongkelan.

"During the latest flooding in January, the floodwater reached up to 1.5 meters in height on adjacent roads and nearly all the houses along the river were inundated," Subianto, 30, a vendor in Cipulir market in South Jakarta, told The Jakarta Post on Wednesday.

Other traders in the market said flooding occurred nearly every year, though not usually as severe as the floods of last January and February.

As with the other rivers in the city, the flooding along the Pasanggrahan River is not only the result of local rainfall. Large downpours along the upper course of the river in Bogor and Depok also spells trouble for people living near the river.

"It is common for the river to overflow and for water to inundate the roads even though there hasn't been any rain here. If the rain in Bogor and Depok is heavy, the water rises very fast," said Pujiono, another trader in Cipulir market.

The upper course of the Pasanggrahan is in the Cilebut subdistrict in Bogor. From there the river flows to Jakarta, passing through Citayam, Cipayung, Sawangan and Cinere.

The quality of the water consistently declines as it moves downstream. In Cipulir, the color of the water is yellowish because of mineral deposits in the river. But in Kembangan, the water turns black from household and industrial waste.

Suwardi, who lives on Jl. Daan Mogot, said residents in the area often complained of the noxious smell of the river. "The bad smell is really a nuisance," Suwardi told the Post.

But the water quality in the river is not as bad as other rivers in the city, including the Ciliwung and Cipinang. This is because fewer people live along the banks of the Pasanggrahan.

Along more crowded riversides, such as the Ciliwung, household trash dumped into the rivers is a major cause of the routine floods.

But there are also a number of bottlenecks that obstruct the flow of the Pasanggrahan, causing flooding during the rainy season.

In Cipulir, one of most populated areas along the river, there are a number of areas that have been narrowed by a build-up of sediment and the illegal buildings that occupy parts of the river.

The walls of some buildings and fences in the Cipulir market bordered directly on the Pasanggrahan River. This has created bottlenecks that disrupt the river's flow.

According to a study carried out by Netherlands Engineering Consultants in June this year, a number of significant obstructions to the river's flow are caused by bridges that were built too low.

The Bintaro Raya and Cipulir bridges are just two examples. The bridges not only obstruct the flow of the water, but they also catch all kinds of rubbish -- from households and industrial operations -- which aggravates the bottlenecks.