Families involved had connections with the Black Power gang and he wanted a better life for them.
Warahi had worked with them before, and the gang connection didn't scare him.
"I was never treated with anything but respect," he said.
He based himself in 69 Matipo St, a state house the trust uses for horticulture and other classes.
"You really had to be there and be with the people."
It was a rocky first few months, after Rippon was murdered and during the court case that followed. Warahi had to make some adjustments.
"I was used to working for a longstanding charitable trust, with an experienced board, and structures."
The Matipo group was starting from scratch. He helped it get charitable status and add people experienced in governance to its board. They included Marama Dey, Lei Graham and Jason Kuru.
The trust continued to find training for its members. Horticulture training was provided by Land Based Training and carpentry training by UCOL - until students decided they didn't want to be bussed to Palmerston North.
Police, the Automobile Association and Te Ora Hou helped with driver training and trust members moved toward getting full driver licences.
The YMCA and Wai Ora Christian Community Trust were also involved in courses.
The community garden was extended and now has a shed and a tunnel house for propagating plants. Anyone can take food from the garden, and there are fruit trees and beehives.
Warahi had hoped to get the young people to a camp, but found they would only go as a whānau.
So there was a whānau camp of 100 at Camp Raukawa instead, "a fantastic experience".
On a personal level, Warahi enjoyed his own mentoring in the programme, and discovered the importance of looking after himself - something he initially thought was "new age waffle".
When his time ended in February the World of Difference Programme also ended. He had been in its last year, and said that was sad.
"It's one more loss of grassroots funding."
