The SA Heritage Council says Port Augusta's Great Western Bridge does not meet the requirements to be listed as State Heritage.
The Great Western Bridge is nearly 100 years old and has been closed since 2017 due to safety issues.
SA Heritage Council chair Sandy Verschoor says the council has found the bridge does not have enough cultural significance to gain a listing.
The Port Wakefield to Port Augusta (PW2PA) Alliance has been awarded the works to demolish the Great Western Bridge on behalf of the SA Government.
City of Port Augusta CEO John Banks says the Great Western Bridge remains under the Department of Infrastructure and Transport's jurisdiction, and decisions regarding its future upkeep will continue to be made by the relevant authorities.
The Department for Infrastructure and Transport says the bridge remains a council asset and discussions are ongoing.