ABSTRACT
A field case study of longitudinal training dams in the Waal River (The Netherlands) is chosen to examine the flow behaviour over a submerged side weir in more detail. Those longitudinal dams separate the main channel from a bank-connected side channel with an upstream submerged side weir parallel to the river axis. An extensive field measurement campaign has been performed, consisting of vessel-mounted acoustic Doppler current profiler (ADCP) measurements, fixed horizontal ADCP measurements, water samples and bed samples. The inflow angle of water into the side channel varies significantly over space (longitudinal, transverse and in the vertical). Vertical secondary flow patterns are primarily caused by sheltering of the lower water column behind the side weir.
