Dale Rhodes, Mullumbimby
Standing on the south wall of the Brunswick River at Brunswick Heads it is immediately obvious what a massive bottleneck the north and south walls create. Every bit of water flooding out of the Brunswick River is bottled up in a narrow channel only thirty metres or so wide.
This must have a massive effect on flooding all the way up the river to Mullumbimby and beyond.
This has been considered in flood mitigation proposals which acknowledge that the river walls are a bottleneck that contributes to flooding. However, the decision was made not to alter the walls, or remove the north wall, in case this led to beach erosion.
Removing the north wall may cause beach erosion, although that is not at all certain. River walls usually cause beach erosion, they don’t prevent it.
But even if during flood events, some part of the beach was eroded, surely this is preferable to a man-made structure causing worse flooding to already vulnerable communities upriver?
Excellent point made about artificially narrowing the river mouths of the northern Rivers . I suggest this equally applies to the Richmond river at Ballina and many other manmade obstructions along the coast ,including but not limited to the Pacific Highway upgrades .