In the mid-1970s, a levee was built along the southern bank of the Shoalhaven River from Nowra Bridge to Terara village. Following floods in the 1970s, the height of the Terara levee was increased to its present level. Terara village experiences flooding from both direct River flow (the levee offers some protection) and backwater flooding from the floodplain. Since the 1970s, the levee has been modified in some places, mainly to provide access to the River. Gradual changes have also taken place, erosion and slumping affecting some sections of the levee. The levee no longer provides a consistent level of flood protection and there is a risk of further erosion and slumping.
The overall objective of the design process was to design a levee and bank protection system that meets the needs of the local community, is environmentally-sound and cost-effective. The following specific objectives guided the design process:
- To upgrade the levee between Ferry Lane and Bryant Street in Terara Village;
- To prevent overtopping of the levee in the 15 to 20 year ARI flood;
- To provide suitable bank protection to limit erosion and slumping of the levee in the future;
- To maintain access to the River at licensed jetties and vehicular tracks;
- To minimise impacts on private property;
- To provide access to a foreshore area in the vicinity of the existing public area in Terara Village;
- To minimise environmental impacts, considering the presence of aquatic and terrestrial flora and fauna in the vicinity of the levee;
- To ensure that the design meets relevant legislative requirements;
- To ensure that the design represents value for money; and
- To ensure that during the construction phase, the design permits construction to be undertaken in the most cost efficient and safe manner with minimal environmental impact (meeting Australian Standards, NSW OH&S requirements and other relevant legislation).