Torrential rain on Saturday created the perfect conditions for water sports on a Papamoa reserve - but the council has warned against such antics.
Local resident Bernard Golder captured footage of a man on a surfboard being towed by a quad bike along the flooded reserve.
Mr Golder said he had been watching the water rise quickly on Saturday morning because of the heavy downpour.
He was out walking the dog later that morning when he spotted the man entering the reserve opposite Harrison's Cut in Papamoa, he said.
Underneath the flooded waterway was a stormwater run-off drain.
Mr Golder, who captured video footage on his phone, said he did not know who the people were.
The surfer was not going "very fast or hooning along like some kind of demon" and he was not impacting on anyone else's safety, he said.
"It was merely two people who decided to have bit of fun on a wet day, and if there was any risk to anyone, it was to themselves."
Tauranga City Council communications advisor Marcel Currin said motorbikes were not allowed on reserves.
"Also, stormwater reserves are not healthy places to swim in, especially after heavy rain, because of contaminants that get washed in from roads, construction sites and who knows where else along with the rain."