This project proposes to use a combination of observations and high-resolution climate model simulations to better understand historic and future changes to sub-daily rainfall extremes for the eastern seaboard of Australia. This improved understanding of rainfall changes will help quantify future flood risk in this densely populated region. This is important because only simplified estimates of future rainfall changes are currently used in industry for flood design. In partnership with the NSW Department of Climate Change, Energy, the Environment, and Water and the NSW State Emergency Service, the project will deliver improved understanding of changes to short-duration rainfall extremes and updated flood design guidance to inform floodplain management in New South Wales.