Council admits sea wall threat
THE rock wall protecting Byron Bay’s central business district from the Pacific Ocean will have to be replaced or risk failing in a big storm, a report has warned.
Byron Shire mayor Jan Barham said the council would take the first step in the long process to replace the 50-year-old structure at its next meeting, when it receives another report investigating the impact of the groyne on sand movement on the town’s beaches.
The council commissioned the sand movement reportafter a University of NSW study found the groyne, which directly protects the town’s memorial pool and the surf club by stabilising the beach, did not meet ‘current coastal engineering standards’.
The report said ‘intervention is required’ to ensure the wall did not fail.
Report co-author and senior project engineer for the university’s Water Research Laboratory, James Carley, said, on a surface level at least, the wall needed bigger rocks that could not be moved by strong seas.
However, he said engineering a wall to hold back the sea was more complicated than finding large rocks.
Before the wall was built, erosion took out an entire street along the beachfront. Cr Barham said it also left the surf club hanging over a precipice, forcing the building to be moved back and leading to the construction of the wall.
Cr Barham said the existing wall, made up of big, jagged rocks, also failed to fit with general safety principles now relied on by the council when building new structures.
She said she would like to see those rough edges removed from a new wall, perhaps in the form of steps that offered seating in front of the bay and offering an easy way for people to access the beach below.
Cr Barham said she had no cost estimates or timelines on the replacement wall.
However, she said it would not happen quickly.
Once next month’s report on sand movement had been received, the next step would be to have engineers design a series of options for the new wall and use computer modelling to test their strength and impact on the surrounding beaches.
Once that process was complete, the council would turn to scale models of the wall, which could be tested in a wave facility at the University of Sydney.
All that was before the council even settled on a design for the replacement wall.
The council will discuss its latest report at its October 14 meeting.