In April 2006, severe tropical Cyclone Monica occurred in Western Arnhemland. The very destructive core of Cyclone Monica (category 5) crossed the Northern Territory coastline about 35 km west of Maningrida with maximum wind speeds of 360 km/hour. The eye of the cyclone passed directly over the Ngarradj Creek catchment which suffered extensive tree fall with estimated wind speeds of 140km/hour. Tree fall in the Ngarradj Creek catchment was widespread and included the riparian monsoon forest along the channel. The resultant flood had relatively small peak discharges at all three gauging stations which were used as monitoring reaches. As a result very little bank erosion was recorded but there were changes in bed elevation despite mean bed-material size not changing. The largest flood occurred in February/March 2007 and was not associated with a cyclone. This event caused far greater channel change and highlights that not all large tropical floods are associated with tropical cyclones. In a companion paper, Erskine and Saynor found that Cyclone Monica significantly increased the large wood loads in the bankful channel because of treefall caused by the exceptionally high wind speeds. The morphodynamic impacts of high winds differ from large floods in this tropical environment.