Posted on November 2, 2022
Beginning on the 16th November, Sunshine Coast Council (SCC) will trial a sand nourishment program.
Using an ocean-going dredge, the vessel will dredge sand from Spitfire Channel – between the southern end of Bribie Island and the northern end of Moreton – and dump it offshore from Alex Beach. The sand may be released via “bottom placement” or “rainbowing”. The former is when the hull splits and directly releases the sand load into the water offering a more accurate and concentrated dump, while the latter diffuses the sand over a wider area and looks just great in photos.
The dredge will operate continuously 24 hours a day up until the 24th November, weather permitting.
There are reasons for Sunny Coast surfers to rejoice, though they’d better wait to see the results before cheering too loudly.
Rather than drop the sand randomly, engineers at SCC plan to account for surfing amenity and place it where it has the best opportunity to improve surf conditions. From the Council website:
“We have been working hard to trial placement shapes that may improve surf amenity along Maroochydore beach. We have been working with engineers that were a part of the Gold Coast Nourishment campaign for the Commonwealth Games to learn from their placement techniques so that Maroochydore can have the best chance at improved surf amenity.”
“We will also work with the University of the Sunshine Coast to analyse the surf before, during and after the placement to see if surf amenity has improved.”
The Gold Coast has a long history of sand nourishment programs, including dredge and dump operations. In 2017, Gold Coast City Council (GCCC) ran a five month nourishment program that shifted three million cubic metres of sand from offshore reserves into the nearshore zone. The project resulted in good, if shortlived, banks at many beaches on the Gold Coast.
The reason Sunshine Coast surfers should temper their excitement is because the coming program will shift much less sand. Just 30,000 cubic metres of sand will be dredged and dumped.
The best outcome would be for the sand to be released via bottom placement which has less dispersal, leading to shallower banks and a greater chance of influencing wave shape. At any rate, this is only a trial program tailored to provide evidence that may guide any further nourishment work.
It will be possible to track where the vessel dumps its load on our Alex Beach surf cam.