NOOSA Waters residents battling to have the Sunshine Coast Council repair its failing canal system have been told the waterway their expensive properties sit beside is really a "common lake area".
The council used this designation in October to deny responsibility for any rectification works.
The Noosa Waters Residents Association blamed a sinking canal bed for damage to a number of revetment walls and cited a 2010 response from former Primary Industries and Fisheries Minister Tim Mulherin to dispute the council's claim.
The minister said: "With respect to the Noosa Waters canal, I am advised that these canals were constructed and approved under the provisions of the Canal Act 1952.
"Section 11 of this act provides that the preservation, maintenance and keeping clean of any canals within its areas are a function of local government."
The council's counter claim was: "The Noosa Waters water body was transferred to the Crown as a common lake area under the Land Act.
"This act specifically prescribed that a 'common lake area' does not constitute a canal under what was then the Canals Act. As such, Noosa Waters is not a canal as prescribed by the Coastal Protection and Management Act."
Association president Gary Trevithick said this advice flew in the face of the council's intervention to fix Chancellor Park Lake and maintain other waterways "from Noosa Sound all the way down the Coast to Maroochydore and beyond".
"The whole thrust here is we are being discriminated against," Mr Trevithick said.
"At Chancellor Park Lake (the council) spent two or three million dollars fixing that up."
He said a motion had been put to fund those repairs through a benefit levy payable by the affected residents. But, Mr Trevithick said, the bulk of the council agreed to pay for it.
"For some reason that I don't know yet, they are saying the residents here can pay for the maintenance of the waterways."
The council's executive director of infrastructure services, Andrew Ryan, said the council maintained Mooloolaba and elements of Pelican Waters waterways because they were "canals, as described by the Coastal Protection and Management Act".
"But Chancellor Park was not a tidal water body that has a management plan and was designed for stormwater management. purposes," he said.
Mr Ryan said the council was helping Noosa Waters residents work through what was "a very difficult and delicate situation" regarding their revetment walls.
"Residents are understandably concerned about this issue, which is why our engineers have provided their expertise and assistance," Mr Ryan said.
He said the council had engaged external engineering advice to help determine suitable remedial action.
"The cause and effect of the revetment wall failure is yet to be established.
"Council acknowledges that owners accept responsibility for the maintenance of revetment walls located on private property to protect private assets.
"Definitive costs will not be determined until such time as the design process is complete.
Noosa Waters Residents will have an opportunity to review and be provided these designs to undertake critical remedial works.