Call in a fluvial morphologist
From REFORM wiki
River restoration designed by landscape architects can be sustainable if the flow energy is low, for instance in small lowland streams or on the floodplains of larger lowland rivers. In environments with higher energies, however, restoration should anticipate subsequent dynamic changes due to natural processes of erosion and sedimentation. Restoration is thus form-based in low-energy environments but process-based in high-energy environments. In the latter case, rivers can restore themselves by letting nature takes its course. Proper design and planning of such restoration projects require trained fluvial morphologists with a background in geomorphology or hydraulic engineering.