Iconic Brisbane restaurant Drift Cafe - formerly Oxley's on the River - has been almost completely submerged this morning.
The restaurant's pontoon has broken away and is floating down the Brisbane River covered with chairs.
"[The restaurant] is very likely to sink sometime today. Salvage efforts were made yesterday, but in the interests of safety those efforts have now stopped," Premier Anna Bligh said this morning.
"Nothing further can be done for that restaurant and it is likely [it will sink]. It is however moored to the banks of the river with very strong steel cables and what is happening is those cables are pulling the restaurant down into the river.
"It is very likely we will see that restaurant sink into the river sometime today or overnight."
Deputy Police Commissioner Ian Stewart said it was "safer to have it in place and sunk, rather than try to repatriate it later".
Owner David Moore sent a text message to friends and colleagues saying the restaurant had been declared a natural disaster.
"I was just asked by the civil engineers to open all windows and doors to let the river flow through," Mr Moore wrote.
"They are expecting that the flood will continue to rise over the next few days and the restaurant will either sink or be washed down the river...
"I'm not in a good frame of mind."
The restaurant was known as Oxley’s on the River for years before being renovated and relaunched as Drift. It controversially beat Matt Moran’s ARIA restaurant to be named best new restaurant at 2010’s Savour Australia Restaurant & Catering Awards for Excellence.