Some of this is rare, cool temperate rainforest, and home to the Mount Donna Buang wingless stonefly, which exists nowhere else in the world.

Jordan Crook, from the Victorian National Parks Association, says the stonefly needs clean, fresh water for its habitat and might be affected by path construction or rider pollutants.

“We’re not against bike tracks, they just need to be put in areas like state forest that are less pristine, and areas of less conservation value that are not critical habitat for endangered species,” Mr Crook said.

Bringing an additional 221,450 visitors a year into an extreme bushfire area poses a significant risk to public safety, according to the Yarra Valley Sustainable Development Alliance.

The alliance is also concerned the size and scope of the project is not proportional to the local area, and its success is based on commercial exploitation of the Yarra Ranges National Park. It would like the council to make more of the data and evidence publicly available.

Warburton is part of an extraordinary rise in government-funded mountain bike projects, including the Ride the Red Centre in Alice Springs and the Blue Derby trails in north-east Tasmania.

The recent environment assessment included the most detailed, extensive analysis of mountain bike trail potential impacts undertaken anywhere in Australia, and perhaps globally, said Matt Harrington, executive project manager for the proposal.

During the consultation, the council received about 2700 submissions and the vast majority, “around 10:1” were supportive, said Mr Harrington. There are already examples of mountain bike trails in national parks in the Dandenongs and Kinglake.

For the council, this is not about mountain bikes but economic buoyancy. It estimates the development will bring $48 million each year to the local region and 230 jobs when completed.

While the native vegetation clearing (which will not include hollow-bearing trees) can’t be avoided to make the bike tracks, their original two-metre footprint will shrink back to between 60 centimetres and 1.2 metres as vegetation regrows, the council estimates.

“There is not another trail project in the country that has gone to the lengths we have to protect the ecology of this region,” Mr Harrington said.

The trail has also been designed to avoid areas of flowing water where the wingless stonefly might live, and the council will monitor sedimentation in the creeks.

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Freshwater ecologist Edward Tsyrlin has been monitoring the stonefly population since 2002 and estimates it has dropped by about 90 per cent. He tried unsuccessfully to have it federally listed as a critically endangered species, which would have triggered additional protection.

The stonefly occurs in a one-kilometre square area, lives in the first 100 metres of ephemeral (non-permanent) streams and is the only Australian stonefly that hatches in the snow.

“I have seen many insects in many different habitats, and I’m still flabbergasted by this little guy,” says Mr Tsyrlin. “From an evolutionary point of view, as a relic, it’s a very special species.”

Mr Tsyrlin was commissioned by the mountain bike project to investigate where the insect occurs and used environmental DNA in stream water to trace two new populations. It’s not the bike trail that worries him, but the associated activities like maintenance, and the effect of car pollution running into streams, he said.

Local resident Andrew Howieson, president of the Yarra Ranges Mountain Bikers, says the group is advocating for the network to be built but not at the expense of the natural world. They support a government-led process because when people are left to build their own illegal trails, it’s a recipe for environmental disaster, he says.

Joel Warham, owner of Cog Bike Shop, in Warburton, also believes it will be good for the town but understands the concerns from locals worried about traffic and increased visitor numbers.

“My thought is it should have been done on a smaller scale initially to let the locals and community get used to the idea and then build it up. It’s a huge project to try and do in one hit.”

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