Another Mangere group was preparing a "park up for homes" on June 16 to show solidarity with the homeless after finding people sleeping in 12 cars in public carparks around Mangere on the same night as the City Mission's inner-city count, May 22.
By yesterday 976 people had pledged on Facebook to attend the all-night "park up".
"We do have a crisis. This is not business as usual," Mr Farrelly says. "It is a crisis unparalleled really in New Zealand."
The word "crisis", he says, comes from an old English usage meaning the point at which a patient could either die or live, depending on whether an intervention was successful. "We are at a critical juncture," he says.
"My worry is that we could, without knowing it, believe that this is the new norm, and become accepting of it and think, 'Oh, this is what it means to live in Auckland.'
"So we have to continue to feel very uncomfortable and really shocked by this, so we can as a community do something about it."
'Stand with the poor'
Mr Farrelly, 64, began his adult life as a priest in the Columban order, whose mission is "to stand with the poor" in the world's poorest countries.
He was the eldest of eight in a farming family that lived in Te Puke when he was born and later moved to Pukekohe. He bussed in to De La Salle College at Mangere.
After studying psychology and philosophy at Canterbury University and training at a Columban seminary in Sydney, he was sent to a slum in Seoul, South Korea, from 1976 to 1987, when Korea was much poorer than it is today.
"My work revolved around building up local communities' response to poverty," he says.
"We established a clinic, built a hospital, a housing development, water and sewerage development."
In 12 years, living and speaking Korean, he says he learned two things.
"I began to understand a lot of the drivers of poverty, and I also saw heroism on a scale I had never seen before ... You see generosity on a scale that is not seen in good times, you see people caring for each other and surviving."
He was inspired to write a theology master's thesis about it at the University of California in Berkeley to help "others working in areas of great need", and returned to Sydney to train others in "cross-cultural work". Then he left the priesthood and came home.
Northland initiatives
Mr Farrelly came back in 1991 to Whangarei, where his parents had settled. He had volunteered at a Sydney hospice with people dying of HIV/Aids, and felt called to a new job in the Northland health board to co-ordinate care for people with HIV/Aids, to lead public education on the issue, and "to work on changing the legislation" which at that time still allowed discrimination on grounds of health status and sexual orientation. He invited Eve van Grafhorst, who had been refused entry to preschool because of her HIV status, to visit Northland the year before she died in 1993.
"This little girl, who was 10 at the time, would speak alongside me and really touch the hearts," he says. She was "embraced by the community" and helped to change the human rights law.
"When a community decides to do something, there is tremendous power in that."
He managed Dargaville Hospital for three years and then primary, community and public health for the region, and in 2003 became founding chief executive of the north's biggest primary healthcare organisation Manaia Health.
He was "incredibly disturbed" by Claudia Orange's 1987 book The Treaty of Waitangi, and part of his sense of being called home was "to understand the treaty more and work within that framework". He learned te reo, formed relationships with local iwi, and set up Manaia Health as an entity owned equally by iwi and doctors, focused on closing huge gaps in health status between Northland's Maori and Pakeha.
He realised that closing those gaps required tackling the drivers of ill health: "poverty, educational under-achievement, unemployment, poor housing".
He helped set up Healthy Homes Tai Tokerau, which provides subsidised home insulation funded by health agencies, the Energy Efficiency and Conservation Authority (EECA), Foundation North (ASB Trust), energy trusts and landlord contributions. The EECA subsidy will be restricted from July 1 to low-income tenants in rental houses built before 2000, but the Northland scheme will keep a wider brief.
"The commitment in the north is not to give up until we can say that, in NZ's poorest region, everybody will live in a warm, safe home."
In February 2011 he issued an incendiary press release headed "Milk more expensive than petrol". "We did a fairly major survey and found that the majority of children in Northland were not drinking milk at all and were choosing to drink cheaper, unhealthy drinks," he says.
The shock tactics worked. That year a parliamentary committee began an inquiry into milk prices that led to a law requiring the Commerce Commission to review milk prices every year. In December 2011 Fonterra announced a trial offering free milk to Northland schools, which it extended in 2013 to all NZ primary schools.
A new challenge
When Dame Diane Robertson retired after 17 years as Auckland's 11th City Missioner and Mr Farrelly was approached by the mission's recruitment agent, he felt compelled to say yes.
He had just finished the Camino de Santiago walk in Spain with his wife, Sue, a Whangarei hospice nurse.
"I took it as a call to reflection," he says. "And I felt yes, this really aligns with my whole life's work."
More than 100 people from Northland iwi brought him south last week for a moving powhiri in St-Matthew-in-the-City, the Anglican church next to the mission which also houses the Auckland Rainbow Community Church.
Mr Farrelly hopes to worship there. "I have belonged to a number of Christian communities in my life and here I feel a call to be aligned with St Matthew's."
The City Mission will continue to offer food and other direct support to the marginalised, as it has since it was founded by the Rev Jasper Calder 96 years ago.
But its 12th missioner says his approach will be inspired by Archbishop Desmond Tutu, who said: "We need to stop just pulling people out of the river. We need to go upstream and find out why they're falling in."
Mr Farrelly says: "That is the role I think now of the mission - absolutely always care for the homeless and the poor, but we must now move to look at the causes."
He expects it to be involved in plans for more emergency housing, using funding announced last month for 800 beds, including 360 in Auckland - trebling the city's current 120 unfunded beds.
He will also work with local and central government to get more long-term social housing.
"I believe that social housing for the very poor, most vulnerable, most marginalised people in our community is a government responsibility and it's for the likes of us to assist them, not the other way around.
"At the moment the indications are that we don't have enough social housing."
He also sees huge holes in our mental health system as a major cause of homelessness, tracing rising rates of reported mental illness primarily to unemployment. "I don't think we have yet, as a country, developed an appropriate system that cares for our mentally ill people at all."
He is sketching a big agenda, and his life experience has taught him he will need to draw in everyone to achieve it. "Any response has to be a collective one," he says. "We as a community can turn this around in Auckland."