Wind-blown sand a problem after dunes flattened

Wind-blown sand in front of the Fish Hoek Beach Sports Club following dune restorations.

Walter Mohr, Fish Hoek

The dune restoration seems like a very good thing to do, especially where the sand is blowing – like by the restaurant on Fish Hoek Beach, Clovelly corner, Glencairn, Simon’s Town station etc (“Dune restoration gets going at Fish Hoek, Glencairn,” Echo May 4).

However, I cannot see the benefit of flattening the sand dunes, at great cost, in front of the Fish Hoek Beach Sports Club’s club house, which was well protected from the wind by the sand dune and grass growing on it for the last 40 years.

On Saturday May 13 the south easter was blowing and the lawn in front of the club house, which was protected by the fully grassed sand dune, is now full of sand.

• Mayoral committee member spatial planning and environment Eddie Andrews responds:

The south-easterly winds that were experienced over the weekend of May 12 to May 14 were highly unseasonal, were stronger and went on for longer than what was predicted.

As a result, windblown sand has accumulated at the back of the beach areas. The contractor went on site on Monday morning, May 15, to clear as much of the sand as possible.

That said, the experience over the weekend is an indication that going forward, we may need to adapt our approach for dune-rehabilitation projects. This is also supported by the long-term predictions that Cape Town will experience stronger winds in coming years, and we will have to take this into consideration in our planning.

Despite the above, it is important not to conflate the extreme windy conditions and the windblown sand with the outcomes of the dune rehabilitation project.

The dune in front of the FHBSC has grown extensively over the last 15 years and will continue to grow each summer season. This will eventually overwhelm infrastructure and as such it has to be lowered. Lowering it now is the best and appropriate long-term strategy in managing the dune system.

This project is very much still ongoing and earthworks will be followed by wind-net stabilisation, planting of dune vegetation and the necessary irrigation.

If all goes as planned, the profiling, stabilising initial planting and irrigation will be complete by June 2023 with follow planting, maintenance and vegetation establishment planned until end of June 2024, after which the maintenance will commence.

All newly established dunes take several years for the new vegetation to fully establish and the dune system to settle.

When dune systems are fully functional, they help to create a quality coastal space for all of us as they help trap sand on the beachfront and prevent it from being blown onto roads and adjacent infrastructure.

This is the most pragmatic and cost-effective approach to managing windblown sand in the city.

Once complete, the vegetated dune cordon in Fish Hoek will provide us with a natural buffer against storm surges and the longer-term projected impacts of sea-level rise, and will mitigate the smothering of infrastructure by wind-blown sand.