MetService says it will review its decision not to issue a rare red weather warning for Banks Peninsula this week.
The area was hit by 10 times the average monthly rainfall in just 48 hours since Monday.
Some locals have questioned why the warning wasn't upgraded from orange to red.
MetService meteorologist Katie Lyons says it's too soon to say whether it was the right call - but they'll analyse it, which is standard practice.
Meanwhile, work is under way to reopen State Highway 75 between Christchurch and Akaroa after the deluge.
Floodwaters are receding on the road after Lake Forsyth was opened to the sea yesterday.
Another stretch of the road has been reopened so the closure is from Birdlings Flat - Jones Road through to Barrys Bay.
A further update on the highway is expected at noon.
A group of 60 students, parents and teachers have also had to stay a second night at Ōnuku Marae in Banks Peninsula.
Ōnuku Rūnanga general manager Jo McLean says everyone at their marae is warm and well.
McLean says it is the third time this year the marae has had to be sand bagged and they are calling for funding for urgent remediation work.
Wainui resident Carl Sloss told RNZ people are likely to be isolated for some time.
The peninsula remains under a state of emergency after the region was pummelled by heavy rain, causing widespread flooding, slips and power and telecommunications outages.
Sloss, who has lived in Wainui for about eight years, says contractors are working to clear blocked roads.
"I think most of the houses are okay. It's just the bridge up by the YMCA which is impassable and the [bridge] along here by the wharf," he said.
"Fulton Hogan are here with diggers now. It sounds like by the end of the day the people at the southern end of Wainui will be able to get out but probably not up the Valley Road, they'll probably be stuck up there for a while."
Sloss says floodwater that gushed down the local creek on Tuesday morning is the most he has ever seen in the settlement.
