When he first arrived on the scene, he knew the nest would be extraordinary because of the large amount of wasps [the vespula vulgaris variety] flying about.
"We're talking thousands."
Firstly the walkway was cordoned off from both ends to prevent people entering the area.
"The last thing I wanted was a school group or a mother and her baby walking past while I was stirring the wasps up."
Then Mr Johnson ventured across the stream, which had a quite a lot of water in it from recent rain, and made sure he had an escape route.
Fully kitted up to prevent a wasp attack, he used a weedeater to clear a lot of vegetation that was obscuring the nest.
Once he had established an entrance that the wasps were using to enter the nest, he sprinkled a powder trail of insecticide called carbaryl.
"Normally a dose of that will be taken into the nest by the workers and passed quite quickly through the colony."
Returning to the site he was surprised to see a large number of wasps flying about.
"Normally if I carbaryl something and go back the next day there will be nothing but in this case there was a lot.
"I thought 'what the hell is going on here'."
He got across the stream again, cleared a bit more vegetation, and discovered a second wing of the nest.
"It went through the toitoi and out the back and then around a bank.
"Once I cut the toitoi down I could see the remainder of the nest.
"And then I actually sprayed it with about a litre of petrol using a backpack sprayer - petrol fumes anaesthetise wasps and they die."
He also used another insecticide, permethrin, before removing the whole nest.
Mr Johnson said there had been a large number of wasp nests this year, and he was going to put together a programme to help council combat wasp nests.
Council regulatory services manager Kevin Currie said council was occasionally called out to deal with wasp nests.
"From previous service requests, it looks like the time we got most reports is in the next couple of months."
People were advised to keep away and not disturb wasp nests.
"If the nests are on private property or inside a dwelling, they should call a pest control contractor, if the nest is on the roadside, council land, park or public reserve, they should call council."