Effects of sluice gate operation on sediment flushing in Bekasi weir using a 1D numerical model

¹ Water Research Laboratory, The University of New South Wales, High St Kensington NSW, Australia
² Directorate General of Water Resources, Ministry of Public Works and Housing, Jl. Pattimura 20, Jakarta, Indonesia
³ Department of Civil Engineering, Parahyangan Catholic University, Jl. Ciumbuleuit No. 94, Bandung, Indonesia

^* Corresponding author: bobbyminola.g@unpar.ac.id

Abstract

Sedimentation upstream of a weir is a common phenomenon, especially for a river with high sedimentation. In the long term, this can lead to problems since the discharge capacity will decrease due to the rise of the riverbed, as experienced in Bekasi Weir, West Java, Indonesia. The upstream accumulated sediments increased up to 1.5 m from its original riverbed in a decade. One of the easiest ways to overcome this issue is to return the riverbed elevation to its actual elevation by manual excavation or sediment flushing using a sluice gate. This paper discusses the effects of operating three sluice gates of the Bekasi Weir for flushing the deposited sediments. The analysis was carried out through 1D modeling using MIKE-11 software to analyze the morphological effects after flushing the sediments with variations of sluice gate opening scenarios. Finally, it was found that without any manual excavation, the flushing method with one fully-opened gate was the best solution by giving a significant upstream bed degradation of up to 1 m, reducing the upstream flood level, and maintaining the upstream-downstream freeboard. The solution could be more effective when combined with river normalization.