A flood study of the Careel Creek Catchment was undertaken to estimate drainage system performance and flood levels for a range of design rainfall events. They were the 20%, 5% and 1 % Annual Exceedance Probability (AEP) events, together with an extreme event. The Careel Creek Catchment has an area of 4.3 square kilometres. The catchment is largely urbanised, with residential, and commercial landuses. Parts of the catchment are forested parkland. Avalon Golf Course also lies within the catchment boundaries. The objectives of the Flood Study were to:

• Identify all the flood related data by searching all relevant data sources.
• Determine the likely extent and nature of historical flooding by reviewing the previously compiled survey of residents in the catchment.
• Define existing flood behaviour of the Careel Creek catchment at the highest obtainable level of accuracy.
• Define design flood levels, velocities and flow distributions for the Careel Creek catchment.
• Estimate flood wave travel times for the flood peak at representative locations in the catchment.
• Map extent of flooding for the 1 % AEP and Probable Maximum Floods (PMF) for the Careel Creek catchment.