Thousands of people have signed a petition calling for the historic causeway from Victor Harbor to Granite Island to be retained rather than replaced.
The Department of Planning Transport and Infrastructure plans to demolish the dilapidated pylons after erecting a new concrete and steel bridge.
Those against the plan are concerned the new bridge will cut through the Encounter Marine Park and part of the Great Southern Reef system, potentially sacrificing swathes of seagrass forest and limestone reef, while also destroying a significant piece of SA's history.
Creator of the Change.org petition, Victoria Pier, joins other opponents (including Eli Bickley from the 'Save the Victor Causeway' community group) in calling for the use of composite materials and resin to retain the old pylons.
"DPTI and Minister Stephan Knoll have just recently announced that composites will be used on the heritage listed Birkenhead Bridge with the upgrade being 'sensitive to the bridge’s heritage design and features'," reads the petition.
"If composites are good enough for the Birkenhead Bridge – why not use this composite technology on our Causeway?"
Member for Finniss, David Basham said it is not possible to save the old pylons.
"Sadly it has actually deteriorated to a point that it can't be saved. Every briefing that I've been given is that the structure itself has got to the point that no matter what you'd do to it you can't save it," Mr Basham said earlier this month.
As the Causeway is a South Australian icon, the petition calls to retain its 150 year old history.
"We have already let so much heritage slip through our fingers, like the swimming baths that were destroyed due to disrepair in the 1950’s. The old Workman’s Jetty, the heritage kiosk, the Harbor Masters Cottage and various other buildings that have been demolished on the Island and in the local area. We can’t let the Causeway slip through our fingers as well. Once it’s gone – it is gone forever," the petition reads.
Photo of Granite Island, Apr 2017 by Leybj003, WikiCommons