"And I think a lot of people blame our current government for that when it shouldn't be the case. Of course, they just want a change.
"With Wellington, we're a very political city. And I'm a proud progressive, lefty, but I know that conservatives voted for me because I was the change candidate."
Whanau said "change" for her meant cracking on to some of the major challenges Wellington had long neglected. She warned that could cause some "disruption".
"We have to get our pipes fixed. We need to get more apartments built. There's a lot of work that needs to be done. There are going to be cones all over the city.
"I just want to be very clear with Wellington, look, it's gonna be disruptive, but it has to happen for the future of our city."
Whanau said she thought voters were after that "reality check".
"I think that's what people like to hear from me, just being very honest.
"We've under-invested in certain things for so long."
On topping more well-known candidate Labour MP Paul Eagle who had the backing of Prime Minister Jacinda Ardern, Whanau said she was "still pinching myself" but put it down to a good plan and strategy.
"I've been planning a campaign for over a year. I wrote a strategy. I did everything by the book. We did a people-powered grassroots campaign, and it worked.
"I think mostly what people wanted to see in their mayor was realness, a real leader."
Whanau is one of few mayors to openly support Three Waters reform and greater housing intensification, particularly in the main centres.
Auckland's new mayor former businessman Wayne Brown, who has refused to do any interviews on his first day of the job, has been a vocal opponent of the Labour Government and particularly Three Waters reform, housing intensification and public transport projects. (left-of-centre predecessor Phil Goff was also a Three Waters sceptic, seeing very little benefit for Auckland).
Former businessmen also took the reins off left-leaning mayors in the South Island's largest cities.
In Christchurch, Phil Mauger defeated David Meates to replace nine-year Mayor Lianne Dalziel, a former Labour MP.
Dunedin also swung to the right with Jules Radich defeating incumbent Green Party-endorsed Aaron Hawkins.
Both southern mayors oppose Three Waters reforms and new housing intensification rules.
Act Party leader David Seymour said the swing to the right showed "New Zealanders have rejected Three Waters and housing intensification".
Prime Minister Jacinda Ardern meanwhile said in a statement on Saturday the Government would keep working "closely" on the "long-term challenges of needing to grow our housing stock, keep investing in transport, public transport and our ageing water infrastructure".
