Meander floodplain management and stabilization of riverbank in urban region

Abstract

The normalization of the Meander River in the past caused environmental problems, changed the river’s ecology, and required heavy maintenance such as stabilizing riverbanks with revetments, sheet piles and other constructions. Pesanggrahan River, located at Southern Region of Jakarta, Indonesia which has a meander channel at the border between the middle reach and downstream reach. The river was normalized at the end of the year 2012 with several modifications such as resection, realignment and cutting-off meandering bends. Analysis the effect of normalization consisting of meander cut-off and riverbank stabilization presented in this paper in term of the behaviour of sediment transport along the channel that has been normalized. HEC-RAS program is used to track the Pesanggrahan river flow from upstream to downstream before and after normalization. The Ackers-White equation used to calculate the amount of sediment for each section based on the change of the river section due to sediment motion after normalizing of the channel river. From the results of the study, it is proposed that a river naturalization or low impact development (LID) approach, such as floodplain management especially at the meander bend with riparian ecosystems that maintain stabilization at the riverbank also maintain habitat heterogeneity, is an important factor for the long-term survival of several rare and endangered species.