In view of the increasing catchment development and the need to accurately define the flood problem, Lake Macquarie City Council engaged Webb, McKeown & Associates, to undertake a Flood Study. The primary objectives of this Flood Study are: • to define the flood behaviour of the North Creek catchment by producing information on flood levels, velocities and flows for a range of design flood events under existing catchment and floodplain conditions, • to assess the hydraulic categories and undertake provisional flood hazard mapping, • to assess the extent of the flood problem by undertaking a damages assessment, • to formulate suitable hydrologic/hydraulic models that can be used in a subsequent Floodplain Risk Management Study to assess various floodplain management measures, including the effects of further development. This report details the results and findings of the Flood Study investigations. The key elements include: • a summary of available data, • reasons for the choice of hydrologic and hydraulic models, • calibration of these models, • establishment of design flood behaviour, • flood damages assessment. The Flood Study does not consider flooding from local drainage which may result from inadequate urban drainage provisions.