The former drying out home for "inebriates" as the historic literature so delightfully - and politically incorrectly - called the clients, had been abandoned in 2005 when drug and alcohol treatment practices changed.
Buying the lease was only the first step, as the buildings were unsafe, the pine trees scraggly and dangerous, ponds and waterways were overgrown and bird-life pretty uneventful.
Clearing started in 2008, planting in 2009 and the island is becoming a textbook case of how quickly nature restores herself when given a helping hand (and a decent cheque).
By last summer the award-winning shed-like visitor centre was opening; roads, toilet blocks and barbecues set up for visitors to explore beaches; and three 70s-vintage houses renovated as smart, retro-style baches.
Only the modern chapel, a tiny two-man jail block and the school house (oddly re-fashioned with colonial verandahs) remain of the original buildings - the rest were demolished and timber and concrete recycled around the island.
Sustainable was the name of the game, and now that the bulk of the planting has been done by professionals, the trust is keen to have locals work on the last swathes. Call it sweat equity, if you like.
A dozen of us took the Coromandel ferry from downtown Auckland early on Saturday. We were a mixed bunch. Some were keen forest and birders, some experienced with plantings for Ark in the Park out west or seedling work around Maungawhau, all of us rejoicing in the ride across the Hauraki on glass-still water, leaving the fog-shrouded city behind.
Ecologist Jo Ritchie, her husband Chris and island managers Phil and Ginnene Salisbury know the island inside out. Their idea of a volunteer programme is a great mix of work and education.
Our task was fill-in planting around one of the first ponds (hopefully to become home to rare teals, if they read the memo).
A cool overcast day was perfect for the work: dig a hole, pop in a fertiliser tablet, plant a flax, bush or wetland grass, cover it up and move on. Jo did rather set the bar high - her professional planters can work at the machine-like rate of 5000 a day, our pace was a little more modest.
Our enemy are the weka - the cunning birds can dig out a day's planting in an hour if the plants are not thoroughly tamped in. We didn't need to be told twice.
The island would originally have been part of the fabled "ring of fire" spoken of by Maori - ablaze with the red of pohutukawa. Replanting the island with these beauties is a long-term project, with abseilers still working on some of the more extreme cliff edges.
Job done, there was plenty of time to walk the island, admiring the Chris Booth sculpture at the southern tip (tonnes of steel and stone installed in a howling gale), planning summer beach trips on the pretty Ladies' and Men's Bay and exploring the smartly presented museum.
A slide show of before and afters gave us an idea of how much work had been done on restoration - and a chance to feel like we'd been part of something special.
Much more satisfying tooling in Auckland's "front garden" than an unappreciated slog in our private back yard.
FURTHER INFORMATION
Arbor Day tree plantings: Auckland Council is leading volunteer planting days for Arbor Day. This weekend at Tauwharanui (Saturday and Sunday, 9.30am) and Oakley Creek (Phyllis Reserve, Sun 10am); next Saturday at Shepherds Park, Beachhaven (9am), Soldier Bay, Birkenhead (10am) and Sunday at Shakespear Regional Park (also Sunday, June 17), Duder Regional Park, Tuff Crater Northcote, Puhoi and Muriwai (all start at 10am). See aucklandcouncil.govt.nz for more details.
Rotoroa Island: For updated news, events and accommodation booking, see rotoroa.org.nz or call 0800 76 86 76. Camping is not permitted, but bach rental starts from winter rates of $250 per night for a six-person cottage, to $500 for a summer 13-person house. Check out the Facebook page here.
Getting there: The 360 Discovery ferry leaves for Rotoroa from downtown Auckland (with a stop-off at Orapiu, Waiheke). Winter Saturday and Sunday departures from Auckland are at 8.45am, returning at 5.15pm (there are more frequent sailings in summer). Adult $49, child $29 return. Discounts available for volunteer days.
