A flood study of the Stony Creek catchment has been undertaken to define the nature and extent of flooding in the area for a range of design flood events. The flood study has been carried out for the existing catchment conditions only. All of the necessary data for the study was collated from various sources, including Lake Macquarie City Council. The Stony Creek catchment lies within the wider Lake Macquarie Catchment to the northwest of the lake entrance at Swansea. The headwaters are located in the west of the catchment in the Awaba State Forest. The catchment drains to Lake Macquarie through Edmunds Bay. The catchment has an area of 46.4 km2 and includes the suburbs of Toronto, Blackalls Park, Awaba and other suburbs to Freemans Waterhole in the west. In the upper reaches of the catchment the land use is rural or bushland. The F3 Freeway passes through the upper reaches of the catchment with a large bridge conveying flow on Palmers Creek and culverts conveying flow for all the minor creek crossings. Other major controls in the upper catchment are the Coal Haul Road and the Great Northern Railway. In the past, flooding in the Stony Creek catchment has caused property damage and posed a high hazard to residents living close to the creeks in the area. In particular, the storm event of February 1981 caused widespread damage in the catchment. The magnitude of this event was greater than the 200 year ARI design event. Lower parts of the catchment, near Fennell Crescent and area to the north of Awaba Road along Stony Creek, are severely affected in major flood events. The number of creek crossings in the area are likely to exacerbate flooding and potential damages to surrounding properties. Flood data was obtained from a number of sources. The data included historical storm and rainfall data, ground survey and hydraulic structure data, recorded flood levels, previous flood study reports and cadastral and topographical data. The data was used to undertake the various components of the study as well as to aid in the presentation of the study results.