Erosion of sand dunes

Whilst on that early morning walk with Kayla I was taken back by the extent of the erosion of the sand dunes around the Granite Island causeway, given the lack of storm surges in the last few months. The Victor Harbor Council’s Development Plan accepts that there will be a 0.3 metres sea level rise over the next 50 years, and the council says that it is committed to the public reserve and development from the anticipated coastal erosion.

We have definitely moved beyond beach replenishment as a sacrificial buffer after storm surges as a short term fix, or the use of wooden groynes in this area as was done between the Victor Harbor yacht club and the mouth of the Hindmarsh River.

The council has been forced into using concrete blocks as a seawall around this area, as well as the area adjacent to the bowling green further east. There are now 3 tiers of concrete blocks forming the seawall protecting the local bowling club on the foreshore.

However, it would appear that even this kind of concrete block protection is not enough to protect the sand dunes around the Granite Island causeway.

Granite Island causeway

The erosion of the sand dunes is only going to worsen with the projected sea level rises, due to the thermal expansion of the oceans caused by climate heating. This means that this part of the foreshore is a vulnerable area with respect to the erosion of the shoreline.