Mullet Creek drains a relatively small catchment of 74.48 square kilometres. The creek rises at the escarpment (often sandstone cliffs) at an elevation of about 600m AHD and flows a distance of about 22 kilometres before reaching the tidal Lake Illawarra. The headwaters are very steep – the elevation falls from a maximum of 600m AHD to 50m AHD in the foothills only 2.5 kilometres further east. These steep catchment conditions provide for dynamic flooding and geomorphic conditions in the catchment. The floodplain near Lake Illawarra is broad and flat, extending up to 2.8 kilometres in width.

This report will form a component of the Floodplain Risk Management Study Report (FPRMS). This report is a stand-alone document that, amongst other things, contains inputs for the Floodplain Risk Management Study Report. This flood study report is a technical document designed to describe the development and simulation of the hydrologic and hydraulic models and present the simulation results for the calibration and design events with existing (predevelopment conditions). The FPRMS report will assess management options and estimate Flood Planning Levels and strategies for future development in the catchment.