The aim of this study is to outline the geomorphic/sedimentary responses of three Slovak river systems of different character (a non-channelized meandering gravel-bed river, a mixed-bedrock headwater river, and a channelized section of a large alluvial river) to extreme flood events. Lateral channel shifts and the spatial variability of channel landforms as responses of a non-channelized gravel-bed stream to flood events were studied on a 13.2 km long reach of the Ondava River in two time horizons, 2002 and 2009 (reference year: 1987). Two different methods were used to quantify the geomorphic effect of floods on the Topl’a River. First is the analysis of the remotely sensed imagery before (September 2006) and after (October 2009) the July 2008 flood. Second is the analysis of representative cross sections measured on each of the 78 delimited channel reaches. Lithofacies studies of the Danube River overbank deposits were conducted on the right-bank inter-dike inundation area (active floodplain) of 300–600 m width. Case studies prove that the responses of different river systems to floods are governed by a combination of ‘global’ laws and ‘local’ spatial and/or temporal factors (different settings and scales).