Balancing river restoration measures around a river bifurcation: A case study from the Netherlands

The Rhine River in the Netherlands still has some characteristics of a delta, although the river is extremely engineered and confined between dikes. An important characteristic are the bifurcation points where the river bifurcates into different branches. The discharge partitioning at the bifurcates is predefined, as this is an important element for the protection of the downstream branches. Adjustable control structures in the vicinity of the bifurcation point facilitate this setting. In order to mitigate higher discharges due to climate change, measures in the floodplains to reduce flood levels are projected. In the planning process, it is important to maintain the discharge partitioning and to guarantee a setting of the control structure such that some control space is left. This can be done by balancing measures. A measure which lowers the flood levels on one branch, should be balanced by another measure on the other branch in order to maintain the correct settings. This requires a careful planning process and careful considerations between flood level lowering and settings of the control structures.