"When I woke up at 6.30am, it was about this far from the top," John says, holding his hands about 30cm apart.
"I thought 'oh my God, this river's going to blow."
He recalled the sight of five members of the Bay of Plenty Regional Council physically trying to hold up a concrete wall holding the water back.
Ten minutes later, the wall collapsed from the pressure.
"Talk about putting your finger in the dyke," says John. "What a joke."
More serious was his concern for his neighbour, a paraplegic and unable to move.
With the help of her carer, John managed to get her out of bed and out of the house.
"Another 10 minutes and it would have been all over."
He ran home to grab a few things and was trying to lock the doors on his shed, when a firefighter started yelling to get out.
"I was driving out the driveway and could see the water coming up behind me," says John.
"The amount of water was horrific, it came up so quickly."
His wife Marilyn was in Whakatane when she got the phone call.
Frantic to get home, she had no idea what she would find.
"The water was getting higher and I was getting frightened for everyone, our neighbours ... the animals," say Marilyn.
"It's just terrifying ... if it happened at night when we were asleep ..."
The couple stayed the night in Whakatane at a motel and face an anxious wait to see the damage to their home, as cordons remain in place around Edgecumbe.
They're frustrated at the lack of information from emergency services, but the Kearns say Edgecumbe is a tight knit community.
Most of the evacuated were shopping in K Mart last night, so will likely be wearing the same clothes today, the couple laugh.
"Edgecumbe will come together once we have to start putting our gumboots on [and pick up] the shovels," says Marilyn.