"Come on you white, male, middle-aged face of local government, let's try something different," Murphy told the meeting.
She said the council makeup showed FPP wasn't effective in getting a range of ages, genders and races around the table in council chambers.
Her fellow Hikurangi-Coastal ward councillor, Greg Martin, took issue with this.
"It's unfortunate being categorised like that," Martin said.
Mayor Sheryl Mai was also in favour of STV at the meeting, Deputy Mayor Greg Innes in favour of FPP.
"Whangārei isn't that bad when it comes to voter turnout compared with others, but it definitely could be and should be better," Mai said.
"If this (shifting to STV) is one way of doing it, bring it on," she said.
Councillor Tricia Cutforth initially moved WDC changed to STV. But Vince Cocurullo then moved an amendment the council instead stayed with FPP.
Councillors voted 8-5 in favour of Cocurullo's amendment. That amendment then became the main motion to be voted on and was passed.
The WDC vote means 51 per cent of Northland's eligible voters will be using FPP for district council voting next time round, 49 per cent STV.
The almost half/half split FPP/STV comes after FNDC recently voted to shift to STV for its 51,800 eligible voters. KDC has used STV voting since the 2004 elections and recently voted to continue doing so. It has 18,900 eligible voters.
The Northland Regional Council (NRC) earlier this year decided to continue using FPP.
Cutforth said the time for WDC and STV would come.
"I'm sorry the vote has not gone the way of STV. I think this council will inevitably move that way, but it may just take a bit longer," Cutforth said after WDC voted to continue with FPP.
"I look forward to a vote in three years' time … I'm positive that eventually good will out."
In FPP, the winner, or winners, are those who get the most votes. In STV, voters are asked to put a number next to each candidate's name, from 1 to 7 for example, in order of preference. If your number one candidate is a runaway winner and doesn't need your vote to get elected, your vote will then go to your second most preferred candidate. If that candidate has also already won a seat, your vote will go to third person you chose, and so on.