Mr McGowan said he was not blaming anyone, and he could see why the legislation had been created but unfortunately it had had an impact on a beautiful and long-standing tradition.
"The event has just had to morph into something that's acceptable these days," he said.
While new health and safety legislation came into force in 2016, requiring event organisers to ensure the safety of workers, volunteers and road users, the Code of Practice for Temporary Traffic Management, which sets out the requirements for traffic management plans, has been around much longer.
Mr McGowan said organisers had got away without having a traffic plan only through ignorance of the rules.
PTA chairwoman Katja Caulton said a lot of work had gone into trying to organise the regatta. There was little the council had been able to do to help apart from trying to minimise the cost to the school.
She had been warned that if the regatta had gone ahead and someone had been hurt, the law could be "ruthless," with serious consequences for the organisers.
She urged Northlanders to support the school by attending the gala at the school from 10am to 1pm on Saturday March 24, featuring old-fashioned games, food, swimming races in the pool and kids' stalls.
Mrs Caulton hoped the regatta could return next year now that the PTA understood the rules with a year to prepare.
Opua historian Myra Larcombe said the regatta began as a community hall fundraiser around 1981. In its heyday 60 dogs took part in the swimming races.
Other community events that have fallen victim to health and safety or food safety laws include the Rawene Races, replaced this year by a mounted games event with no food stalls, and the Ngunguru School gala and fireworks display.