Drownings at private swimming pools have risen in the last 18 months, and the number of child deaths has water safety advocates worried.
The increase in drownings occurred after law changes to pool fencing and safety last year, though the advocacy groups said it was too early to make any connection.
After reforms in the 1980s, the drowning rate in private pools in New Zealand was drastically reduced to around three a year. There was just one death in 2015 and 2016.
But that jumped to eight drownings last year. And so far this year, another five people have died in private swimming pools.
"Every preventable drowning is a concern for us," said Water Safety NZ chief executive Jonty Mills. "And there has been a bit of a jump in statistics in the last couple of years."
Starship Child Health director Mike Shepherd also said he was concerned at the recent child drowning statistics.
"It is a timely reminder of the importance of making your home environment safe, including keeping unsupervised kids out of pool areas.
"International research has proven that four-sided isolation fencing and a self-closing mechanism gate is the best possible way to achieve this."
Three of the child drownings last year are still being investigated, including two-year-old Saylor Rose Kerlin, who was found unconscious in a family friend's pool in October. Coronial reports have been completed on the other two deaths.
In one of them, one year-old Avarie-Wyatt Ireland drowned at a pool on a Gisborne property. The coroner's report found the pool was properly fenced and had a self-closing gate, but the gate only closed if left to swing shut from at least one-third open.
In the other case, one year-old Dallas Jones was found floating face-down in a pool at a Warkworth property.
The pool did not need a fence because it was higher than 1.2 metres and was not easily accessed by children. However, temporary steps which were usually removed from the pool by the family were left in place and Dallas climbed into the pool and drowned.
At the beginning of 2017, new legislation came into force which aimed to improve swimming pool safety while also making the rules more practical.
Most of the changes by the National-led Government were welcomed, especially more regular council inspections of pools.
A few changes were controversial, including more relaxed rules for fencing spa pools and automatic locks on gates around swimming pools.
"Certainly fencing around pools and restricting access to pools for toddlers is a real concern for us," Mills said.
"But It is early days in terms of linking the impact of drownings to [the law changes] specifically right now.
"From an under-five perspective the only fool-proof solution is constant adult supervision."
Former Building and Housing Minister and National MP Nick Smith, who led the 2017 law changes, said he had been advised that five years of drowning data was needed before any firm conclusions could be drawn.
But the death of five children in residential swimming pools since early 2017 was very concerning, he said. Officials should be seeking information on whether those children had died in non-compliant pools.
Around 90 per cent of child drownings in private swimming pools are attributed to faulty gates or fences, he said.