Christchurch City Council said most of the fire was now under control, the last major cordon for residents has been lifted and most evacuees had returned home.
Nevertheless, a state of emergency is still in place and fire services are continuing operations because of the risk of flare-ups in forecast warmer weather.
Port Hills is the Lake Okareka crew's third external fire deployment this summer - following January's Whitianga fire and Te Pohue's 100 hectare fire, inland of Napier, earlier this month.
"This is my ninth deployment and it's Ray Doyle's seventh deployment, so we're very experienced," Mr Muldoon said.
Mr Muldoon said the crew could not be there helping if it wasn't for the generosity of their employers agreeing to give them time off.
"We appreciate the support from our employers for releasing us to be able to assist in other areas. That's very important, when you volunteer."
Pumicelands Rural Fire Authority chief executive Paul Wright said it had been an unusually busy season. There are 25 Pumicelands-area firefighters helping in Christchurch.
"We've been able to release quite a few of our firefighters to go to these incidents," Mr Wright said.
"This year we've had it all - we've got people involved in the incident management teams, right through to the actual firefighters doing the hard work on the ground."
He said while the fire was contained on the surface, the battle had now moved underground. Buried logs and tree roots can catch fire and cause fires to flare up.
"That's what the crews are doing down there now - they're not fighting a fire, they're digging out hotspots and hosing them out with water. That's where most of the work is. It's very hard work."
The image below shows the extent of the fire damage. The red is vegetation, shown in two photos: the left image on Monday, and the right taken last year.
