Watson said it was a flaw that meant councillors couldn't access employer contributions to their KiwiSaver.
"For many councillors around the country, this is their job," Watson said.
"I accept that for basically everybody around this table they do it because they are interested in their district but it just seems to me to be an anomaly.
"I think that's an issue that maybe we could raise. I think the option should be made available."
But councillor Cath Ash didn't support the idea.
"I personally see what we do as a civic duty as opposed to a job," she said.
"I believe we get enough as it is and I don't really support pushing it higher."
Councillor Dave Wilson said a councillor's salary was taxed at source like any other job and councillors could opt out of the scheme if they didn't feel it was justified.
Whanganui mayor Hamish McDouall said elected officials were still entitled to make voluntary contributions to KiwiSaver and would be hesitant to add further to rates via extra employers' contributions.
McDouall said there should always be a service component to being a councillor and that it wasn't the same as being employed.
But he was open to discussion.