STUDY OF SEDIMENT CONTROL, CASE STUDY : DADAP RIVER AND ESTUARY, BANTEN PROVINCE

• Main Author: Agus Stiawan, Yogi
• Format: Theses
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/80745
• Institution: Institut Teknologi Bandung

The northern coastal area of Jakarta is the estuary of rivers that originate in the southern region, including artificial canals. The rivers that flow into Jakarta Bay have a severe problem with high sedimentation rates and flooding problems. The Dadap River often experiences flooding in the estuary. Dadap River is located in Kosambi District, Tangerang Regency. The problem of flooding in the Dadap River is due to the lack of capacity of rivers and estuaries caused by sedimentation. The flooding that occurred caused damage to city infrastructure and paralyzed the activities of the affected residents. The Dadap River was normalized in 2012 to overcome the flooding problems. The purpose of this study is to determine the effect of normalization on sedimentation and morphological conditions in Dadap river and estuary, and as an alternative solution for sediment controlling. This study was also conducted to determine the capacity of the Dadap River, which affects flood problems. Sedimentation simulations were carried out in conditions before and after normalization. The simulation was carried out for 10 years which Boundary sediment modeling uses the daily discharge and sediment curve in upstream and downstream tides. Grain size is inputted upstream, middle and downstream. Flood modeling simulations were also carried out in conditions before and after normalization and alternative embankment elevations. Flood modeling was using the HEC-RAS 1D unsteady flow application. Modeling will be carried out with boundary conditions in the upstream using flood discharge with a 50 and 100 years return period and downstream using HHWL elevation and wave height. The sediment modeling results show that the morphological condition of the Dadap River, after normalization, occurs sedimentation in the downstream and erosion in the upstream. The lower flow velocity downstream (estuary) causes sedimentation to occur. Based on the results of the sediment simulation, there was an increase in the amount of sediment transport in the Dadap River after normalization from 506.042.9 tons/10 years to 754.195.3 tons/10 years. Sediment control solutions need to carry out routine O&M activities every year, amounting to 189,334 Tons so that there is no significant sedimentation in the Dadap River estuary. Sediment trap at the discharge outlets from housing or factories can be used as an alternative to overcome solid sediment from household/factory waste. In addition, there is a need for non-structural efforts in the form of socialization and education to the community regarding river maintenance and enforcement of rules for people who throw garbage into the river. The results of the flood modeling analysis showed that the capacity of the Dadap River before normalization was not able to drain the 50 and 100-year return flood discharges. After the normalization of the Dadap River, the water level may decrease by about 24 -29%. However, there is still flooding downstream due to the tides, so it is necessary to raise the embankment elevation of +3.5 m to overcome the flooding caused by the tides.