Michael Walker-Mitchell was allowed to roam the streets of the East Coast settlement of Te Karaka, as long as he watched out for dogs, kept off the road and was home by dark.
Good rules, but "daredevil" Michael was just four and didn't stick to one of them - to stay out of a property 108m from his home because there was a disused water tank there.
Four days after his fourth birthday he wandered on to the property, into the 1.8m deep tank and drowned.
Hastings Coroner Chris Devonport, in a report released today, found Michael died of drowning last June 4.
His family raised the alarm when he failed to return by 5pm, having last been seen at 3.30pm. Others in the village were called, and police were notified at 7pm. Michael's body was found just after midnight, submerged in the water tank.