The foundations of the almost 200-year-old instalment do not lie on a wealthy estate, or even on town land, but in the South Esk River.

Perth resident John Stagg said the historic river dam by the Midland Highway bridge, constructed in 1820, was rapidly deteriorating.

Mr Stagg shared his concerns with the Northern Midlands Council during its general meeting last month.

"I feel that it would be lucky to last another winter with the way it's deteriorating," he said.

"There are willows growing up through it, pushing the dam apart.

"Last flood we had took the middle part out completely ... it's the worst I've ever seen it."

Northern Midlands corporate services manager Maree Bricknell told Mr Stagg that the council had done minor repair work on the dam.

Northern Midlands Mayor David Downie also said the council had sprayed willows in the area during that month.

Mr Stagg said there were only another seven or eight weeks left this year to restore the dam, if it was to remain.

"I feel that it's part of an icon of Perth, it's definitely something worth preserving," he said.