THE STUDY OF FLOOD MANAGEMENT IN BEKASI AREA

• Main Author: Reza Robby Nugraha, Muhamad
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/52171
• Institution: Institut Teknologi Bandung

The Flood that occurred in January-February 2020 have inundated almost all areas of Jakarta and Bekasi. Bekasi area was the worst affected by the flood. High rainfall of up to 377 mm which is measured at Halim Station is a trigger for flooding, in addition to other factors such as massive housing construction, reduced capacity of Bekasi River, and large discharge due to the conversion of green open land in Bogor Regency. Flood control efforts in Bekasi River are based on previous projects including long storage, normalization, cliff reinforcement, embankment, and dam. However, the dam construction plan is considered as an effective long-term solution to overcome the flood. The construction of the Narogong Dam is planned to be built in 2020-2025. This is contained in the Ciliwung-Cisadane River Basin Management Plan 2019. The progress of the dam construction plan until 2019, namely DED Narogong Dam Phase 1. The dam location plan is in Cileungsi River on the border of Cibadak Village and Karang Tengah Village, Sukamakmur District, Bogor Regency. The maximum design volume of the reservoir is 27.51 million m3 with an inundation area of 95.46 ha. The flood tracking through the Narogong Reservoir using HEC-HMS program shows almost no reduction in the flood discharge. The peak inflow discharge in the reservoir for the 25-year flood return period is 37.7 m3/s, and the peak outflow discharge is 37.2 m3/s. Because of the results, it is proposed to move the dam location downstream, which is located in Klapanunggal District, Bogor Regency, namely The Citeureup Reservoir. Thus, Citeureup Reservoir is a new proposal that has never been conducted in previous studies. The maximum potential volume of Citeureup Reservoir is 62 million m3 with inundation area of 310 Ha. The dam function as reservoir detention, the volume of the reservoir is reduced in the rainy season to provide space for flood storage. Under the flood storage, water is used to supply raw water to the Bekasi area. The results of flood tracing through the dam show that Citeureup Reservoir is able to reduce flood discharge by 253.4 m3/s with flood return period of 25 years. Apart from flooding in Bekasi River, flooding also occurred due to the blockage of the siphon building by sediment and garbage in the 12 rivers that cut Kalimalang. The blockage in the siphon caused the flood discharge to be blocked and it overflowed to inundate the surrounding area. To overcome this blockage, it is proposed to establish a pilot channel downstream of the Kalimalang siphons. The pilot channel allows trash and sediment not to be obstructed and can be flushed continuously, especially during normal conditions but not flooded.