Durban — The South African Association for Marine Biological Research (Saambr) has explained why there are piles of sand and dredgers changing the beach landscape in Durban.
Saambr said that visitors to the Durban beachfront might be wondering why there were piles of sand and dredgers.
The association said that our beaches lose approximately 280 000 cubic metres of sand due to naturally occurring sand erosion each year. To compensate for this loss, the eThekwini Coastal Management team pumps sand on to the beaches to regain as much of the beach width as possible.
It said that the eThekwini Coastal Management team, as part of their planned maintenance, does regular inspections of the piping and pumping equipment. During a recent inspection, they discovered damage to a section of their 900mm high-density polyethylene (HDPE) piping under uShaka Beach. The above picture shows the team replacing the damaged section.
Saambr lead technician Travis Bunsee explained: “The sand needed to replenish the beaches is dredged from the harbour entrance and stored in hoppers, which are located close to the harbour entrance. The sand is pumped from the hoppers to the beaches through large pipes located under the sand.”
“To help loosen the sand and enable movement through the pipes, water is injected into the pipes from the jet water station. This process loosens the sand, allowing it to be sucked up and pumped to different booster stations along the coastline.”
Last month eThekwini Municipality clarified that it is not pumping sewage into uShaka Beach. The municipality also backed up its statement by sharing an article from Saambr that explains what is happening at the beach.
At the time, municipality communications head Lindiwe Khuzwayo said the municipality would like to clarify that the City is currently busy with a sand-pumping operation on the beachfront close to the harbour mouth. It is done annually to ensure that our beaches remain in pristine condition for all beachgoers.
“The sand-pumping scheme creates a recreational beach and pumps approximately 280 000 cubic metres of sand on to the beaches every year. This also acts as a buffer between the beach and infrastructure.
“The harbour breakwaters prevent the natural migration of sand from south to north on our beachfront, necessitating the sand pumping operation. If the city did not pump sand, our beaches would erode away with the action of the waves,” Khuzwayo said.
She said that continuous beach monitoring programmes are in place to provide sediment data on the beaches, which guides the sand pumping scheme.
Khuzwayo said that the darker colour of the sand is because of naturally occurring minerals such as quartz, feldspar, titanium and ilmenite which are black in colour. This should not be confused with oil or a sewage spill.
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