The Nepean River and its headwater tributaries, the Avon, Cordeaux and Cataract Rivers, rise in the Illawarra Range to the west of Wollongong at an elevation of about 500 in. Mount Keira (450 m) and Mount Kembla (550 m) are prominent peaks in this range. After draining heavily timbered country in its headwaters the Nepean River is joined on its left bank by the Bargo River and about 15 km further downstream by the Cataract River on its right bank. Downstream of this junction the river flows in a generally north-westerly direction for 40 km until it reaches the township of Camden. The catchinent area at Camden is 1380 sq km. The Nepean River and its tributaries are controlled by four dams, operated by the Metropolitan Water Sewerage and Drainage Board, which form part of the headwaters storage for Sydney. Details of these storages are given in Table 2.1 None of these storages has a specific allowance for flood mitigation. They do not normally result in any substantial reduction in flood flows passing down the Nepean River, although the pattern of flooding at Camden is to a small extent dependent on their storage contents prior to the commencement of a flood and the contributions from the downstream tributaries.

The report comprises five sections and three appendices of supporting data. Section 2 assesses the nature and magnitude of the flood problem and its effects on the current land use pattern in Camden. In Section 3 flood damages are assessed. These include direct damages to residential, commercial and industrial development which were quantified using the services of professional loss adjusters. In addition, damages to infrastructure were assessed as well as indirect costs due to preparations for, and evacuation during, floods, cleanup and loss of trade. Section 4 outlines possible flood plain management options. A total of five options was considered, as follows: Do Nothing Progressive Evacuation of Flood Affected Areas Zoning Measures to Allow Change of Use Flood Proofing of Selected Existing Properties Leveeing of the Study Area. In Section 5, the proposed strategy is outlined.