AU - Beneath the Surface: Bleak future for our beaches without action now
(New South Wales, Australia) - The iconic beaches of Port Stephens took a hammering in 2021. Given the escalating impacts of climate change with increased frequency and intensity of storms on shoreline stability, it can only get worse.
This is a long-term problem that will ultimately impact the local economy. We need to start looking after the natural assets that are Incredible by Nature, as our tourism slogan promotes, and that underpin the local tourism industry. Perhaps it is time to consider alternatives to the business as usual approach to erosion.
Constructing rip rap rock walls, or geotextile sandbagging and beach nourishment have not proven to provide a sustainable long-term solution. Planting native shoreline plants is one solution, but is site-specific and usually too little too late. The removal of native plants on the foreshore reserve in favour of buffalo grass is poor practice. Regular watering results in soil and nutrient runoff, while the shallow roots of introduced grasses do not stabilise the shore. Surprisingly, the council does nothing about this, despite it being their land.
Port Stephens in $20m Reef Builder expansion plan, Port Stephens Examiner, OCTOBER 14 2020
Rip rap rock walls, may be useful for protecting shoreline infrastructure, they preclude the return of beaches to an area and the erosion problem is transferred along the shoreline. It becomes a game of whack-a-mole until the entire coastline is built up with rock walls - not a good look for future tourism.
Geotextile sandbags are generally considered to be a temporary measure while a more permanent solution is developed. These are often used in conjunction with beach nourishment, introducing additional sand to the beach as a long-term solution. But if wave attenuation (direction and strength) is not addressed, the wave action that promulgated the problem will continue.
Wave action is the primary driver of beach erosion. This comes in two forms: refraction, the change in direction, wavelength, and speed of the waves due to a change in water depth, and diffraction, where the waves bend around an obstacle(s).