The tidal branch of the Sea Scheldt between the lock of Gentbrugge and Melle - part of the complex Ringvaart system around Ghent - has not received any upstream discharge since 1981. Consequently, ebb velocities were reduced, while flood velocities were left unaffected, causing sedimentation in the branch. At some locations along the branch, odour nuisance was regularly reported. In order to address the problem, Division Sea Scheldt of the Flemish Government proposed to dredge the associated muddy material. Flanders Hydraulics Research (FHR) was asked to conduct a study about the necessary upstream discharge at the lock of Gentbrugge needed to ensure the river branch’s self-erosiveness. To answer this question, monitored data were combined with modelling know-how. A 2D numerical morphological model was constructed, for which hydrological and sedimentological parameters, such as discharge, gauge height and sediment concentration, were used as input and for validation. All of these data were provided by FHR. After numerous numerical scenarios, it was concluded that the discharge required, lies between 20 and 25 m 3 /s. However, as a mean discharge of about 70 m 3 /s is discharged into the entire water system around Ghent, and as other waterways within this system require sufficient discharges (of which the Canal Ghent-Terneuzen has been determined in a Belgian-Dutch treaty) this discharge is not available in normal circumstances in the tidal branch. Currently, Flanders Hydraulics Research is investigating the possibilities of a lower discharge at the weir of Gentbrugge, that would allow to maintain the branch with a limited dredging.