All Opotiki eyes on Cyclone Gita after a month's rain fell overnight Sunday

Opotiki residents left relieved when the rain eased and rivers receded will now be turning their minds to Cyclone Gita's arrival later this week.

The town centre saw a month's worth of rain fall in the town within 24 hours from Monday while the deluge caused more than 300mm of rain to accumulate in some areas from Sunday through to Tuesday.

Opotiki Mayor John Forbes said about 20 per cent of the town was flooded and damage could cost the Opotiki District Council upward of $1 million.

State Highway 2 between Opotiki and Gisborne and State Highway 35 toward Torere were both closed briefly while several other roads were cordoned due to flooding.

A Pakihi man, who only wanted to be named as Matiu, said he and his family were isolated by several slips, one of which he believes has knocked the home off its foundations.

"My dad left for work early Monday morning and made it through but, as I made my way to my job in Whakatane, a flash flood came through and raised the river level in seconds," he said.

"We had boulders rolling down the hill behind our home and have been staying at our neighbours since then.

"There was a guy trying to clear the road of slips who told me he'd cleared about 20 small slips just to get to our house."

Opotiki District Council spokesman Gerard McCormack said clean-up operations were well under way and the council was getting a handle on the damage.

"There is still a lot of ponding around the district and it will be a few days before debris is cleared and damage repaired."

Pumps were being used to drain parts of the township today. "The wastewater pumps kept working through the event but with the massive amount of water things were just too full and there was nowhere for the water to go."

McCormack said river systems held up well with the Otara at highest-ever recorded levels.

"This coincided with a high tide on Monday evening so the town stopbanks held up well although there was some overtopping in rural areas."

The town schools were able to open today although some classrooms were down in numbers.

Pupils at Opotiki Primary made the most of the situation this morning.

Taking advantage of the metre-deep water on their field, they stripped down to shorts and took a dip while others kayaked their way across "Lake Opotiki Primary".

School principal Tony Howe admitted things got "quite close" on Monday afternoon.

"The rivers were right up there, especially the Otara which was lapping at the top of the stopbanks."

Opotiki's Motu Trails executive officer Jim Robinson said most of the rain was east of the Waioeka catchment.

"I'm expecting the Pakihi Track to have sustained some damage, I'm just hoping it won't be too severe.

"On the plus side, when the track gets storm damage, it's typically only about 5km that gets slips and debris, the rest is fairly stable."

Bay of Plenty Regional Council flood duty manager Graeme O'Rourke said the team was in planning mode for more possible extreme weather later this week.

"We are now turning our eyes to a possible future event with quite a few models showing Gita making landfall somewhere nationally later in the week.

"We'll get more certainty on that over the coming days so at the moment it is a matter of keeping an eye on the situation across the region and modelling different scenarios."

Meanwhile, Toi Te Ora medical officer of health Dr Neil de Wet warned Bay of Plenty locals to avoid swimming in streams, rivers and beaches for 48 hours after heavy rain.