Should rock walls be built or entrances dredged to keep ICOLLs permanently open to the ocean?
It is sometimes suggested that the best way to ‘fix’ perceived ICOLL problems is to undertake works such as building rock training walls, groynes or regular dredging to permanently open the estuary to the sea. However, lake entrance works are very costly (millions of dollars) and can have many undesirable effects including permanently changing the ecology of the lake (including fish stocks and fish habitats), changing flood behaviour in the catchment, creating tidal currents and influences on sediment movement, and altering tidal flushing that may lead to poorer water quality and higher salinity in backwater areas. Often the perceived problems with ICOLLs (e.g. flooding and poor water quality) can be better managed by increased public awareness of ICOLL environments, and dealing with issues in the catchment (e.g. reducing polluting inputs, relocating or raising assets and infrastructure) than undertaking costly entrance works. It is important to recognise that ICOLLs have always been d
