Widespread, spatially coherent flood events can cause severe damage and disruption. Climate change has the potential to change the severity and frequency of such events. Despite this, climate change risk assessments of future fluvial flood risk typically give little to no consideration to potential changes in the spatial structure. To understand the significance of this gap, spatially coherent climate model simulations are coupled with a national hydrological model and a statistical Empirical Copula to develop a set of present and future fluvial flood events. The research finds that changes in the spatial structure of widespread fluvial flood events have the potential to materially increase projected changes in risk when compared to conventional approaches to climate change risk assessment that ignore them. Excluding changes in the spatial structure of events may mean projections of future expected annual damages maybe significantly underestimated by a factor of ~1.5. The event-based approach is also shown to provide new insights into the extreme distribution of single event damage, damage seasons, and damage years of fluvial flood risks across Great Britain. The results suggest the 1-in-100 year winter flood may increase from £1.3b to £2.1b and the 1-in-100 year single event damage may rise from £1.1b today to £1.7b by the 2080s given a 4°C rise in Global Mean Surface Temperature, assuming current adaptation policies continue and no population growth. Consequently, the findings suggest a much greater emphasis is needed on spatial ‘flood events’ if future risk is to be understood and adaptation responses appropriately framed.