OUR COASTAL TREASURE
Impacts on the Dunefields
Human interference – in the form of development – with the dunefields has had a negative effect on the local ecology.
For example, it contributed to the erosion of the St Francis Bay beach. The building of Santareme on the Santareme dunefields directly impacted on the replenishment of sand on the beach.
A headland bypass dunefield is a kind of conveyor belt for sand – it travels cross-country instead of round the coast. The dunefields play an important role in maintaining the sand levels at either end, as wind and waves push sand onshore at one end and move it across to replenish the beaches at the other end.
There once were four headland bypass dunefields across the St Francis headland. Three of them still exist – the Oyster Bay dunefield, the Thysbaai dunefield, and the Cape St Francis dunefield.
But the Santareme dunefields are now the foundation for houses, gardens and roads. The sand that was once washed onto the St Francis Bay beach is now trapped under the suburban infrastructure, and the beach is no longer the wide and welcoming seashore it used to be.
Sand from the Oyster Bay Dunefield too, which used to reach the beach directly, is now washed into the Kromme River. The dunefield once ran through the present-day canal area, joining the coast around the point where Grand Canal meets Ski Canal.
Inappropriate development and use of land in and around a complex headland bypass dunefield system, say the scientists, has disastrous effects, including destruction of infrastructure.