Hoons are smashing barriers, driving cars on to sports fields and leaving a trail of destruction through parks and reserves in South Auckland.
Auckland Council is urging residents and sports clubs to be "extra vigilant" after vandals hit 15 times and damaged eight parks over the past two weeks.
"Most of the damage occurs at night and out of sight, making it difficult to identify the offenders," said Malcolm Page, the council's local and sports parks (south) manager.
"In a few cases where registration plates have been sighted, they have turned out to have been stolen or unregistered vehicles."
Although much of the damage was surface and had not caused any cancellation of games, Mr Page said, there was still a cost.
"Extra mowing and handwork is required where turf has been ripped out," he said.
"It is extremely disappointing to see people treating public spaces in this way."
Mr Page asked people to call the police if they see anything suspicious.
"Taking down the vehicle registration and any other details to pass on to the council would be a huge help."
The council had installed bollards and fences, but in some cases these were removed or broken through.
Mr Page said the council was aware that vandals had also struck some Central Auckland parks.
Counties-Manukau police spokeswoman Shelly Nahr said officers were working with the council.
Paul Burns, chairman of the Fencibles United Association Football Club, which uses the Riverhills Park and the Greenmount Reserve, said one field on each of the two grounds was "unplayable at the moment". He believed the fields would be put right in time for games at the weekend.
Council parks ranger Scott Malcolm emailed sports clubs last week urging members to report suspicious behaviour or cars near parks.