Sand can be trucked in from other sources and filtered for sediments to eventually make way into the air and water. They can also build seawalls, revetments, and jetties along the shoreline. :)
I think it might be erosion because erosion breaks down objects
As an Australian myself I can safely inform you that it is definitely Australia, despite the common misconception that the capital of Australia is Sydney or Melbourne.
It belongs in the Northeast region.
