There are about 70 intermittently closed lakes and lagoons (ICOLLs), along the NSW coast. The Coffs Harbour area has a number of ICOLLs such as Woolgoolga Lake and Hearnes Lake. ICOLLs alternate between being closed or open depending on rainfall in the catchment and the movement of sand as a result of wave action, tides and winds.
Council manages the ICOLLs in accordance with the relevant Coastal and Estuary Management Plan. Most of the time it is better to let the ICOLL self-regulate and not artificially open the lake. This short animation tells the story of what can happen to ICOLLS and their residents if the entrance is artificially opened.