What is dredging?
Dredging is the process of moving sand from one part of the ocean floor to another. This happens by using a dredge vessel, which takes sand from the seafloor, and stores it on-board. The vessel then moves to the desired location, and the sand is released, falling to the bottom of the ocean. An image of the dredge vessel, the Albatros, which has previously been used to dredge the Tweed River entrance can be seen below.
Why is it needed?
The two objectives of Tweed Sand Bypassing (TSB) are to establish and maintain a safe, navigable entrance to the Tweed River, and restore and maintain the coastal sand drift of the southern Gold Coast beaches.
TSB is made up of both the sand bypassing facility and periodic entrance dredging. The jetty collects most of the coastal sand drift, but some sand still moves past the jetty and into the Tweed River entrance. This sand builds up over time, requiring periodic dredging.
The sand is removed from the Tweed River entrance and deposited to locations offshore.
Keeping the Tweed River Entrance safe and clear of sand is vital for the commercial and recreational boating community. It allows commercial fishermen access to the ocean as well as providing tourism operators, commercial yachts and other recreational water users continued and safe passage.
Moving the sand from the entrance and placing it in strategic locations protects coastal assets and supports the coastal lifestyle that is an integral part of the region’s identity.
Where is dredged sand placed?
Tweed Sand Bypassing has a number of locations where it can place sand which is removed from the entrance during dredging. The image below shows these locations.
When will the Tweed River entrance be dredged again?
The Tweed Sand Bypass team regularly monitor the state of the entrance and the condition of the beaches. The frequency of dredging depends on how much sand has built up in the entrance.
When dredging occurs it is undertaken in the calmer months of July, August and September.
Why does the dredge moor at Kirra?
The dredge vessel is unable to remove sand from the Tweed River entrance when there are waves breaking on the entrance. This happens with larger swells and at low tide. When this occurs, due to the orientation of the coastline, Kirra is the safest place for the boat to be, and it may frequently be seen stationed here during a dredging campaign.