The catchment of Duck Creek is shown on the Locality Plan, included as Exhibit 1 . Overtopping of the access road and culvert, occurring on several occasions during the past few years, has disrupted the activities of the Yallah TAFE Agriculture College, leading to the need to upgrade the TAFE College crossing.

This study Involves a hydrologic and waterway Investigation of the existing road crossing over Duck Creek providing access to the Yallah TAFE Agriculture College, near Wollongong. In addition, conceptual design works required to upgrade the performance of the crossing are reported. This study has been undertaken in accordance with procedures recommended In the 1987 edition of Australian Rainfall and Runoff (ARR-1987).

The study catchment area is approximately 9.5 sq km to the TAFE College crossing, and 12.4 sq km to the Princes Highway.

The objective of this study is to establish working hydrologic (RAFTS-XP) and hydraulic (HEC-2) models for the study catchment under existing and developed catchment conditions to determine flood profile tailwater information to be used in the design of the TAFE College crossing upgrade, and to develop proposals for a flood free crossing to the 5% and 2% AEP levels within the budgetary constraints .