Nearshore Nourishment Implementation, Monitoring & Model Studies of 1.5M³ at Kirra Beach

The southern Gold Coast beaches have suffered serious erosion (approximately 7M m3) since the construction of the Tweed River training walls to the south of the Gold Coast in 1962-1964. As it was considered that nearshore nourishment would be the likely method chosen to solve this problem, analytical studies were undertaken by the Water Research Laboratory for the Gold Coast Council. This was done in order to provide a qualitative assessment of the impact on coastal processes of the dredging and nearshore nourishment at various depths and to examine the applicability of the modeling techniques for predicting future nearshore nourishment behavior and options. Forward ray wave refraction computer modeling techniques were employed to examine the sensitivity of the shoreline wave climate to offshore dredging. Model studies showed that, in general, dredging in areas seaward of the 20m depth contour is not likely to have any significant effect on shoreline conditions. Despite adverse conditions, the works carried out in 1988 appear, as predicted by the model investigations, to have been effective in protecting the foreshore and allowing accretion of a usable beach.