Fast facts about the sand recycling underway from Semaphore to Adelaide’s struggling southern beaches.
Adelaide is losing West Beach and Henley Beach South. A short-term measure to make sure these beaches don’t disappear, is to truck sand from Semaphore to these eroding southern beaches.
Sand has been carted to West Beach and Henley Beach South from the Semaphore South breakwater since October 2018. The beach between Semaphore and Largs Bay jetties has been identified as back-up sand source to use when the primary source of Semaphore South breakwater needs time to naturally replenish.
- Why can’t Adelaide’s coastline just be left alone? Adelaide’s roads, houses and other infrastructure were built along the foreshore before it was commonly understood that Adelaide’s sand naturally moved south to north. Maintaining a stable coastline by recycling sand allows us to enjoy sandy beaches, as well as saving South Australians from the costs of damaged assets and infrastructure.
- Why does sand need to be shifted? From all the studies and evidence, the most practical and cost-effective ways to deal with erosion on Adelaide’s southern beaches are to recycle sand from Adelaide’s northern beaches, and bring in additional sand from external sources.
- How much sand will be trucked from Semaphore? Around 300,000 cubic metres of sand will be trucked between the two sand sources at Semaphore for the next two years until 2021.
- What about the health of Adelaide’s northern beaches? Semaphore beach is built-up with lots of sand. As sand moves north on Adelaide’s coast, the Semaphore area will naturally build-up again, as it did when similar sand carting occurred in the early 2000s, 1990s and 1980s.
- How’s the health of Adelaide’s southern beaches? West Beach and Henley Beach South are eroding quickly. Today, beach levels at West Beach and Henley Beach South are lower than at any other time since records began. The beaches between Kingston Park and Glenelg have been maintained by sand pumping system along that part of the coast since 2013.
- When will the sand trucking happen? Trucks will cart sand for up to 10 weeks three to four times over the next two years (avoiding school holidays) from October 2019. The trucks will alternate between the two sand collection sites for each stint of sand carting. Road trucks will operate between 7:30am and 5:00pm, Monday to Friday.
- Why not build groynes to hold sand on beaches? Structures like groynes, breakwaters and seawalls can be used to help trap sand and protect infrastructure. But, to manage Adelaide’s coastline well, groynes are not the answer. They are costly to install, require large quantities of sand, interrupt recreational beach use, are visually unappealing and can cause the coast on the southern side of the structure to become starved of sand. By focusing on sand shifting for protection of Adelaide’s beaches, long sandy beaches can be achieved without the additional cost and side-effects of expensive structures.
- Why is this not ‘sand mining’? Sand in being recycled not ‘mined’. It is the sustainable management of a finite and incredibly valuable resource, and we have been doing it for nearly 50 years.
- How can a member of the community find out more? Local residents will be kept informed. To find out more visit the Adelaide beach works website.
The Government is delivering the Securing the Future of our Coastline program, a long-term solution to restore and maintain the sand at West Beach and Henley Beach South. As part of the program, a sand recycling pipeline will be built from Semaphore to West Beach, and about 500,000 cubic metres of external sand will be imported to make up for sand losses over the years.