A third of Auckland swimming pools have failed safety checks since more regular inspections were introduced last year.
And one pool owner was so negligent about fencing off their pool that they ended up in court.
Homeowners must now get their pools inspected every three years rather than five years after a law change in 2016 which aimed to improve swimming pool safety.
Since then, Auckland Council inspectors have checked 9343 pools and found that 3298 of them were non-compliant.
The most common problems were self-closing gates which did not work and climbable items next to fences which children could use for footholds. Many pools had non-swimming items inside the enclosed area, like vegetable gardens or clothes lines, which are not permitted.
The council was also concerned about unconsented alterations and the removal of pool barriers in between inspections.
"Of course any non-compliance presents a risk," said Auckland Council's Steve Bloxham, who is in charge of swimming pool compliance.
"Unfortunately, it seems some pool owners may be relying on the council's inspections as a reminder.
"It makes no difference whether the pool is cheap or expensive. The rules are there to save lives."
Homeowners whose pools are found to be non-compliant are given 21 days to fix their barriers, or 48 hours if the faults are dangerous. If they fail to fix the problem, they are given a "notice to fix" or are taken to court.
In the last 18 months, 23 pool owners have been given warning notices and one has been prosecuted.
The pool owner who was prosecuted had failed to empty their pool while they were fixing a range of fencing issues. They were convicted and fined $500 plus court costs.
The law changes which came into force last year also relaxed some safety measures. They allowed spa pools not to be fenced if they had a lockable lid and for alarmed gates to be used rather than automatically locking gates.
The number of drownings in private pools has risen in the last two years — though that trend is not believed to be linked to the recent rule changes. Five children under five have drowned in home pools over this period.
Of the coroner's reports which have been completed for those child drownings, the coroner found that the pools were compliant and that the deaths were partly the result of children not being supervised.
• 31,607 private swimming pools in Auckland
• 9343 pools inspected by council since new laws came into force in January 2017
• 3298 pools non-compliant
• 23 warning notices issued
• One conviction for non-compliance