The study investigates flood behaviour throughout the Gwawley Bay catchment. This includes the analysis of:

1. surface runoff across the catchment
2. flows within the underground pipe drainage network
3. flooding within Gwawley Creek and other watercourses towards the lower part of the catchment; and
4. backwater flooding in Gwawley Bay from the Georges River.

A two-dimensional computer model was established for the catchment to analyse flood behaviour under existing catchment conditions. The model provides information on the extent of flood inundation, flood depths and flood velocities throughout the catchment for design floods ranging from relatively frequent events to more extreme floods.

Outcomes from the Study

Outcomes from this study include:

1. a database of all drainage assets within the study area;
2. establishment of computer models capable of assessing flood behaviour;
3. information on flood behaviour under existing catchment conditions; and
4. a model that can be used to assess flood mitigation options and future development proposals.