They also threatened to oppose McDouall's choice of deputy mayor, Jenny Duncan.
Whanganui has suffered from divisions in its district council in the past, and McDouall — who stuck to his guns in appointing Duncan — knew he needed to act.
"After the wastewater treatment plant was dealt with, I reflected on the situation over the summer," he said.
"I thought, 'These guys haven't come here to be obstructionist ... everybody elected has Whanganui's interests as their key goal'."
In February 2017, he called them to a meeting at the Whanganui Club in St Hill Street.
"It was deliberately off campus; deliberately no council officers.
"I said, 'Okay ... what do you want to achieve?'
"It was almost universal — everyone wanted to grow Whanganui, whether that's population or gross domestic product or some other expansion.
"I think that started breaking down barriers," said McDouall, acknowledging that the four newcomers all had strengths and skills to offer.
"It was a bit of luck, a bit of good management, and we've been a solid team ever since."
McDouall confirmed to the Chronicle that he will stand for the mayoralty again at this October's elections.
"But I won't commit beyond another three-year term because there are things I want to do in life.
"And politicians can get stale if they stay in the job too long."
He said his time so far had gone very quickly — "and I'm still learning".
In 2016, there were seven candidates standing to replace outgoing mayor Annette Main, and while McDouall expects a challenge, he doesn't anticipate that size of field.
"There were a couple of very good candidates there — Alan Taylor and Helen Craig. Now they've seen me perform and might think, 'He's all right, we can cope with him for another three years'.
Reflecting on the highs and lows on his two-and-a-half years as civic leader, McDouall picked the 700-plus population rise on each of the past two years as a bright spot, crediting the work of Whanganui & Partners.
"We altered the governance structure, making it a smaller operation but putting money into staff," he said of the council economic development agency.
"Whanganui & Partners has had some substantial successes over the past 18 months."
That included efforts in bringing the 2019 Labour Party conference, the pilot academy; and new businesses coming to the city.
"We have 400 new businesses in Whanganui. Most are self-employed, single individual, but they've come here with assistance from Whanganui & Partners."
Securing the Labour Party conference was, of course, a personal highlight for the three-time Labour candidate.
"We were fighting against Rotorua, and we sold Whanganui in terms of its authenticity.
"I remember when the Labour hierarchy came here and they were a bit nervous about our capacity to hold the conference.
"But once they walked into the War Memorial hall and saw the Opera House, they said, 'All right — you can actually host it'.
On the downside, the mayor expressed frustration at the slow progress over the port development.
"That the port hasn't come along as quickly as I'd hoped is a disappointment. There's millions of dollars and numerous stakeholders involved, so it takes time.
"The port frustrates me, but we are finally kicking it down the road. No new port will ever be built in New Zealand, so we should retain what we have."
And finally, the mayor's idea for an event to boost the economy and vibrancy of the city following the success of the likes of Opera Week, Vintage Weekend, NZ Masters Games and Artists Open Studios.
"In the off years from the Masters Games, at around the same time, we should have a Homecoming Weekend.
"I get to Wellington, Auckland and elsewhere and I meet people from Whanganui ... their parents are still here or they went to school here," he said.
"Every two years they could come back. We'd appoint Whanganui ambassadors, chef Peter Gordon could be here, House of Shem could play ...
"A Homecoming Weekend could be really good — it would be about celebrating people from Whanganui and they'd know their family and friends would be here."
Certainly an idea to think about.
One recent issue that has sparked some controversy is the government's decision to make Whanganui a centre for up to 100 refugees each year from 2020.
Mayor Hamish McDouall admitted it had been "a cause of contention" for two reasons.
"One is xenophobia, and I'm not going to help anyone with their own xenophobia.
"But the second issue is housing and people have valid concerns.
"The past 18 months to two years has seen a housing crisis, particularly in the rental market."
However, he said the influx of refugees would be scaled to the supply of homes, and was confident re-settling the newcomers could be managed as central government would be funding it.
"It is a central government decision and that means central government money."
McDouall said the council had taken some measures to try and address the housing situation. One of those was retaining its portfolio of pensioner housing, something he had fought to keep when there had been discussions about possibly selling off the properties.
"We have also opened up land to the west of the city for new builds."
He said council was also looking at putting accommodation above the shops on Victoria Avenue.
"It used to be packed, I remember when I was younger — everyone used to live upstairs.
"And a lot of people want to live in the city, and that creates energy.
"So we have many levers to pull with regard to housing, and Housing New Zealand investment will also assist."
He envisaged a small task force — representatives of council, iwi, district health board, English language partners and others — to "provide a proper welcome".
And he said the task force would also lobby government for funding where it was needed.
"Not a dollar of ratepayer money will go into it."
And he added: "People have been emailing me with Islamophobic comments, but the refugees could be from anywhere ... Columbia, Sri Lanka, Nepalese. We don;t know where they will come from."
