Posted on December 5, 2022
Central Coast Council has asked to defer the dredging of The Entrance channel so it’s better suited when the conditions are required at a later date.
Council recently received a grant from the NSW Government to carry out dredging of the channel but hasn’t used the funding yet as dredging hasn’t been warranted.
Dredging the entrance to the Tuggerah Lakes now would provide little value to the community (in terms of flood risk reduction) as the channel is currently in a ‘moderately open’ condition – which means water is flowing easily between the ocean and the estuary.
Council is constantly monitoring the estuary and carries out flood mitigation and has also recently released the Tuggerah Lakes Entrance Management Study, including the Interim Entrance Management Procedure, to the community.
Council has dredged The Entrance channel, when needed, since 1993. The entrance condition and shape is constantly being shaped by coastal and catchment processes, as well as weather and climate drivers, which help Council determine when it’s applicable to dredge.
When dredging is needed, if it takes place after high rainfall, sand is removed (scoured) temporarily from the entrance. During dryer conditions and droughts, and when coastal processes dominate, sand is pushed into the channel, resulting in the berm growing and sand shoaling. The Interim Entrance Management Procedure recommends Council’s actions in the event of a predicted flood event.