"Some customers in more remote rural areas may not be restored until later next week,'' he said.
On Thursday night and Friday morning more than 30,000 homes were cut off as storm winds brought down power lines and trees across the region.
Mr Douglas said there were now pockets of streets which were not reconnected.
"There are a heck of a lot of small areas, where a tree's taken out a suburban street or something [left],'' he said.
During the clean-up, teams had been prioritised to deal with major outages first.
"If a substation's out, you fix it [first],'' he said. "If a high-voltage line goes out and you can get thousands of people back on, you fix it.''
The capital’s transport network is on the way to return to normal for commuters tomorrow.
Bus services across the capital are expected to run as timetabled. Most bus routes are running today, but buses to Eastbourne run only as far as Hutt Park.
KiwiRail trains on the Johnsonville and Kapiti Coast lines are on normal Sunday timetables today and will run as scheduled tomorrow.
There will be delays on the Hutt Valley line, which had a section of track washed out by the storm waves on Thursday night.
Services on the Wairarapa line will also be delayed and there may be bus replacement services.
The Interislander ferry Kaitaki suffered damage to the roof of its atrium area during the storm and will be out of action for at least two days.
Spokeswoman Sophie Lee said the roof would be assessed this afternoon.
‘‘We need to put scaffholding up on it to have a look at what needs to be done,’’ she said. ‘‘The Kaitaki will be out for today and tomorrow, when we’ll reassess it.’’
The ferry broke free of its moorings on Thursday night and had to anchor in the harbour to ride out the storm, assisted by tugboats.
The other Interislander ferries, Aratere and Arahura, will make three round trips today and tomorrow.
More comprehensive details on transport for Monday will be released later this afternoon.
The Dominion Post ferry between Queen's Wharf and Days Bay is sailing again for the first time since Thursday night. Passengers have to take care at Days Bay as there is storm damage at the start of the wharf.
Next week should be much calmer, bringing welcome respite for battered communities across the Wellington region.
A weatherwatch.co.nz forecast predicted a dry and sunny week for the capital, as a south-westerly flow runs over the country.
It could bring some showers to Wellington on Friday, head weather analyst Philip Duncan said, but otherwise conditions will be much improved compared to the end of last week.
A low sitting in the Tasman Sea could track onto the northern North Island towards the end of the week but its path was unclear as yet, he said. It appeared to be too far north to cause problems in New Zealand.
The rest of the country can expect showers and messy, unsettled weather throughout the week, with most rain hitting the south and west.
However, compared to the ferocity of the Thursday and Friday storm, the overall picture is much calmer, he said.