Australia: Sand Causes Problems for Coffs Harbour

Joint cooperation between the NSW Government and Coffs Harbour City Council is the only long-term option to deal with the problems caused by sand infilling the harbour, a report to Council has concluded.

“Scientific studies have shown that the breakwaters and land reclamation associated with the harbour captures virtually all of the sand that used to travel north, replenishing the more northerly beaches – and it’s accumulating in the harbour,” said Ben Lawson, Council’s Director City Infrastructure Services, who wrote the report. “The resulting sand build-up is causing ongoing problems for the commercial fishing fleet, the marina users and boat ramp users.

“These can be tackled with a number of short-term solutions, but in the long-term, a more permanent solution is vital – and the issue is bigger than Council alone.”

Mr Lawson’s report proposes that one of the most beneficial measures may be to have sand regularly dredged from the harbour and placed off the northern breakwater. This is an option that the NSW Government is now investigating, primarily as a means of reducing the risk of waves overtopping the northern breakwater.

“This would have the potential to address three problems at once – reduce the risk of waves overtopping the breakwater by creating a form of artificial reef, reduce the amount of sand infill into the harbour and replenish the beaches further north. However, the feasibility of this proposal is yet to be assessed.”

Mr Lawson’s conclusions are contained in a report that outlines the current plans to address the problems with surge, or wave, action at the boat ramp. Council and the Coffs Harbour Boat Ramp Working Party have been looking at two options – extending the boat ramp’s breakwater or extending the basin itself. Both would help dampen the surge action.

In addition, small-scale dredging has now begun to reach areas not accessible by Council’s long-reach excavator, which is regularly used to remove sand from the boat ramp. A much larger dredging operation is also proposed after the boat ramp works are completed. These works are due to begin in September.

“While extending the breakwater and basin will help reduce surge action at the boat ramp, the sand infill that’s causing the current problems will remain unless a longer-term solution can be found,” said Mr Lawson. “This is as important to the NSW Government as it is to Council – and both bodies face substantial and increasing costs to keep the harbour navigable. It would be beneficial to both if we worked together on a long-term answer.”

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Press Release, April 11, 2014