Lake Macquarie council will use 35,000 trees and plants to transform an old quarry at Redhead into a haven for native flora and fauna.
Early work on the multi-year rehabilitation project started at the three-hectare Oakdale Road site this week.
More than 4000 trees, 10,000 shrubs and 20,000 vines, ferns and other ground cover species will soon be planted in the area, including spotted gums, blackbutts, scribbly gums and smooth-barked apple trees.
More than 90,000 tonnes of clean earth will also be trucked in from construction sites across the city to help fill the quarry void and reshape the site to aid drainage and minimise erosion.
"The Oakdale Road quarry has been a dumping ground and hooning hot-spot for unauthorised dirt bikes for many years," project manager Tim Browne said.
Public access to the site, which is earmarked for community use rather than natural bushland, will be restored once the project concludes, likely in 2023. Lake Macquarie Landcare will provide the bulk of the plants.
"The existing cliff will still be a feature of the site, but earth will be built up against it to create a more natural final landform that slopes down into the middle of the quarry," natural assets officer Brooke Laforest said.
Lake Macquarie council originally leased the site from NSW Crown Lands to quarry gravel for local construction projects, but it has not been used for that purpose since the 1980s.
Mr Browne said similar works were nearing completion at West McDonalds quarry at Glendale.