Impact of Heron Island Boat Harbour Upon Its Adjoining Reef and Cay

The history of the interaction between Heron Island boat harbour and shoreline changes at the western end of Heron Island in the southern Great Barrier Reef was previously reviewed in 1983. Since then reef-top tidal currents have continued to flow out through the harbour channel, the boat harbour has been enlarged and a dredge spoil dump constructed on the south-western side of the island has modified the shoreline processes and released silt onto the reef-top. Construction of bund walls to control tidal outflow and sand loss through the boat harbour was completed in March 1994. The continuing monitoring of the effects of these walls, together with the impacts of tropical cyclones Fran (1992) and Rewa (1994) upon both the harbour works and the island, is discussed.