Sand dilemma

Waverley Council last week received a complaint from a longboard surfer who was very angry the council was using a tractor to push sand back towards the water.

He claimed this would change the sand bars in the bay and affect the surfing.

Mayor Sally Betts asked council staff to explain why the procedure is necessay.

It seems that the seawall completed around 1928 has effectively stymied the natural flow of sand that once ran all the way to Rose Bay. There were a series of sand dunes that ran between the ocean and the harbour and these would change subject to the prevailing onshore or offshore winds.

With the stabilising of the sand dunes and construction of the seawall in the early 20th century, the sand blown against and over the seawall now has to be pushed back with a mechanical grader or shovelled up and taken back on to the beach. Essentially, the sand is just being pushed back into the water – this would have no effect on the sandbanks in the water.

There are two storm water outlets at Bondi Beach, one at North Bondi and one at South Bondi. The stormwater outlet at Nth Bondi has little effect on the geography of the beach as it discharges into deeper water off the rock shelf at that end of the beach. The storm water outlet at the southern end of the beach would undoubtedly have an effect on the dynamics of the sandbanks and rip currents in that immediate area as it discharges into shallower water.

The greatest impact on Bondi Beach in the past 20 years has been the improvements to the sewage treatment plant at Nth Bondi and construction of the Deep Ocean Outfall that discharges treated sewage a couple of kilometres out to sea.

The improvement to water quality at Bondi Beach is astounding when compared to previous conditions, where at times swimmers and surfers had to contend with untreated sewage out in the surf.