The seemingly endless meetings of last term was a gripe among councillors and it's hoped a new structure will allow them to spend more time in their communities.
The Long-Term Plan and Finance and Performance committees have also been rolled into one. This will be chaired by Labour councillor Rebecca Matthews.
Labour councillor Teri O'Neill will chair the Social, Cultural and Economic committee.
These three committees include all councillors, while the remaining four committees consist of a mix of elected members and independent officials.
The new committee structure replaces the one former mayor Andy Foster put in place last year after an independent review found the council was in need of a circuit breaker.
Whanau said in a statement this afternoon that trust, experience and the ability to work together were at the heart of the appointments.
"It is important that the leadership positions on the committees are filled by people who have the ability and experience – that includes work, council, and life experience – to lead and shape good decisions on behalf of all Wellingtonians."
The move comes after Whanau appointed Green Party councillor Laurie Foon as her deputy mayor.
Whanau told Newstalk ZB Wellington Mornings host Nick Mills that former councillor Jenny Condie was her first choice, who she described as "non-political", but Condie failed to be re-elected.
Whanau said she then took into consideration her mandate, who would help her realise that vision, who she trusted, and who had the trust of council staff.
She couldn't have another rookie, so that's how she ended up landing on Foon, Whanau said.
Whanau also confirmed she has been given a briefing on the council's finances.
"And I won't lie, there's a lot there, which is why I've been lobbying the Government pretty hard already to get that support", she said.
"I think water infrastructure in particular is going to very expensive and as I said on the campaign trail, that will impact rates, but we're not up to that level of detail yet as council hasn't started."
Asked whether she was confident there would be no surprises like Auckland Council's $270m budget hole, Whanau said she was "pretty confident".
