Auckland Council is ramping up its efforts to catch recidivist offenders who use closed walking tracks in the Waitākere Ranges - and risk spreading kauri dieback disease.

Photo: RNZ / Jordan Bond

The council has laid charges against a man under the Public Safety and Nuisance Bylaw after he was caught three times on a closed track, and have issued almost 50 trespass notices to others.

The council said it was locals who were their own worst enemy, claiming 95 percent of the offenders live nearby.

A local walking guide, Geoff, was pleased when he heard someone was being taken to court for refusing to stay off closed tracks.

Photo: RNZ / Jordan Bond

"There's got to be some deterrent to tell people we're trying to stop the spread of kauri dieback disease. They have to follow the rules. Life's full of rules, this is just one of them," he said.

David Alexander moved here a year ago, and heads to the ranges about once a week.

"It seems like the most frustrated people are the ones who've lived here all along, and have always used these tracks," Mr Alexander said.

"I can understand a little bit if this is your home, it's probably hard to see part of it closed. It's one of those things if you want other people to be able to enjoy it, you follow the rules and do the right thing."

The disease travels by soil - once it gets into kauri roots, there's no cure, and the trees slowly die. Kauri are considered taonga - a treasure - and they're a keystone species; about 17 other plants depend entirely on kauri.

Auckland Council closed the tracks in the worst condition to minimise soil movement, and is upgrading some with elevated board walks or laying more gravel.

Compliance manager Steve Pearce said most people respected the closures, but others needed deterring.

"Depending on which rules you break, we'll use whatever tool we think is appropriate. That can include a fine... that can include a trespass, and infringement notices."

Mayor Phil Goff said it was regrettable that the council has had to prosecute over the closures, but the man being taken to court was entitled and ignorant to the impact spreading the disease would have. The accused faces a maximum penalty of $20,000 per charge.

Photo: RNZ / Dan Cook

Almost 40 tracks are open or partially open in the Waitākere Ranges.

Dr Mels Barton from the Tree Council said many of them were not in a good condition, and would not do well with a summer influx of walkers.

"The tracks that were not closed right at the start are in a terrible state. They're absolutely shocking. They're far worse than when Te Kawerau ā Maki[mana whenua] said they were suitable to be left open," Dr Barton said.

"Absolutely no work has been done on any of those tracks whatsoever in the last two years."

Auckland Council parks manager Rachel Kelleher said they had been working hard to upgrade a range of tracks all around the region, and they were regularly assessed and maintained.

She said they have been using the winter for behind-the-scenes work.

"We're three-quarters of the way through the design work for our five-year programme, so we've made some really good progress," Ms Kelleher said.

"Right now is really the time when our track programme on the ground is ramping up, and we're physically carrying out work on a number of tracks in the Waitākere Ranges, Hunua Ranges, Wenderholm Regional Park, Tawharanui, Shakespeare.

"At the moment we've got physical work happening in the Waitākere Ranges on around six tracks and that's about to ramp up very shortly. There's going to be a lot more track available to the public in coming weeks and months.

"If things continue as they are, we expect to probably do more than 15 or 20 kilometres above what we'd planned to this year."

Ms Kelleher said a few tracks would open very soon, and others shortly after Christmas.

Te Kawerau ā Maki - the mana whenua who implemented a rāhui in 2018 to close the entire park - did not respond to requests for comment.