Current Observations: Cisadane River Levels Recede, Water Quality Declines
The water level of the Cisadane River in the Bendung Pasar Baru area, Tangerang City, Banten, has receded significantly due to the prolonged dry season. This condition has also impacted water quality, which has turned a greenish-black colour and begun emitting an unpleasant odour.
To maintain sufficient water levels for raw water supplies, all sluice gates at Bendung Pasar Baru, including Sluice Gate 10, have been closed and have not been discharging water to downstream areas for approximately the last month. Observations on Friday afternoon showed that the Cisadane River behind Sluice Gate 10 is experiencing shrinkage, with large rocks that are usually at the riverbed now clearly visible from the surface.
This condition is being utilised by some local residents for fishing and netting fish. According to data from Bendung Pasar Baru, the water level of the Cisadane River in front of Sluice Gate 10 reached 10.95 metres on Friday afternoon, a decrease from the normal elevation of 12.45 metres. Meanwhile, the water level behind Sluice Gate 10 was recorded at approximately 5.50 metres.
The closure of Sluice Gate 10 was implemented to preserve the availability of raw water for clean water processing. However, amidst the decreasing discharge, the quality of the Cisadane River water has also changed colour to greenish-black and produced an unpleasant smell.
A local resident, Bambang, stated that the quality of clean water supplied by the local government’s water treatment plant has recently been deemed poor. According to him, the water received by residents is yellow and turbid. Furthermore, well water in the surrounding area is also considered unsuitable for bathing and washing.
“The PDAM (local water utility) water is not good; it is somewhat yellow and quite smelly. The benefit is that people around here can fish and net fish. That is the blessing of the Cisadane water drying up,” said Bambang.
The recession of the Cisadane River water level has occurred gradually over the last three months. This condition is expected to continue unless there is rainfall or additional water supply from the upstream area, namely the Batu Belah Dam in Bogor, West Java.