Scour holes are depressions in the riverbed that can pose a significant risk to bank stability. For that reason, a better understanding of the distribution of scour holes in the biggest rivers of the Dutch lowlands is important. In this podcast, we speak to Bas Knaake from Deltares who has dedicated his PhD research project to mapping the geological factors contributing to scour hole formation. He explains why it is especially in the western part of the Rhine-Meuse delta where scour hole formation is linked to the Holocene architecture of the delta.