The council learned 18 months ago it was in breach of its consent for the breakwater if it allowed public access to the 1872 Heritage New Zealand category 1 structure.
Access to the breakwater had since been stopped, while the council undertook a safety review on advice from Canadian management and consultancy service WPS Global Inc.
Waitaki District Council assets manager Neil Jorgensen said the new signs gave a clear message.
Security contractors had been used in the past to remove people who were on the breakwater to see Oamaru’s blue penguins, often international tourists, he said.
"Hopefully this new signage will help people understand that there isn’t public access [to the] breakwater allowed."
The council’s safety review was under way but had been a "relatively slow" process.
"We are getting a resource consent to allow public access on to the breakwater. Obviously safety is a key part of that, but the other key part is working out how it would work with Doc because obviously there are birds that nest and seals on the breakwater as well."
He could not comment further on the matter until discussions with Doc were complete.
Maintenance work was being carried out on the breakwater, as it took a "real hammering by the sea".
Ultimately, the council wanted to allow access to the breakwater if it was safe to do so.
"I think the community [has] always enjoyed having access to the breakwater and having a look, it is a pretty cool location and it would certainly be great to be in a position where we could have access again. It is a unique structure — it is pretty neat."
The small beach near the breakwater was still accessible.
