He is dressed as Superman, in a blue jumpsuit, red briefs and a cape, albeit with the addition of a floppy hat to keep off the light rain persisting down.
Johnstone donned it to keep spirits up at the dig-out around his very munted home and property on Allen Rd, Pākōwhai after Cyclone Gabrielle swept through.
His family climbed on the roof here and stayed there for two and a half hours when the cyclone flood ripped through on February 14, before a boat took them off.
Johnstone likes to joke.
“That’s where I walk the washing out, to hang it out,” he says, indicating a small courtyard with hedges on two sides, where a worker, who identifies himself as ‘Mr Ed’, is on a digger scooping out muck.
“No, no it’s not,” Johnstone corrects. “This is a place that has beautiful gardens, lots of little nooks and crannies and what-have-you.
“And you know, we’ve had weddings here and all sorts of different occasions.”
Over his shoulder, behind a gate and shaded by avocado trees, is a swimming pool, now dirty brown.
“It’s now a mud pool,” says Johnstone.
“If it was in Rotorua, it would be famous. We’ve got our own mud pool.”
Any superpowers he has can do nothing for the avocadoes.
“I can see from here avocadoes must hate this, because that avocado there, that little one there, the other one behind and one here, they’ve already started turning up their toes.”
The family home of two decades is full of spirit-quenching mud.
“Come and have a look, my friend,” says Superman.
His boots squelch into the open-plan kitchen/living area.
“In the morning when I got up after that stormy night ... we’ve had heavy rains before ... yes, it was a little bit deeper than normal, but it wouldn’t have been any more than half a gumboot, and no water inside.”
As a precaution, he moved his stock to a higher part of the family’s four hectares.
“About 10 o’clock we lost power, and that’s obviously when the stopbank has gone.
“It’s coming through here, whoom,” where he is standing by the deck door leading into the kitchen, “and then it came through there, whoom. It just poured in.”
“We lost 130 sheep, and 15 pigs ... all drowned.
“If this had happened at 10 o’clock at night, we would have been caught in our beds.”
Atop the physical task, Johnstone is trying to get his head around insurance and what the options are for rebuild or repair.
“Apart from the house and the vehicles that you can actually see, there’s a lot of things under [it], like tile drains - they’re going to need blowing out.
“The list goes on. It’s mind-boggling.”
His Superman suit is a bit dirty by now.
There is no hot water, and only cold showers at the end of the day at the bed and breakfast the family is staying at. But it is never so grim that he can’t find some relief.
He spots Ed sitting back in the digger, having a smoke.