The company building the controversial HS2 railway line has underestimated its impact on habitats and wildlife, according to a coalition of wildlife charities.
A report from the Wildlife Trusts found that HS2 Ltd had lost trees, ponds and hedges from the maps.
He said the methodology used to calculate the project’s biodiversity impact was “fundamentally flawed”.
HS2 Ltd said the relationship of trusts was “not reliable”.
The trusts are calling for construction to be halted and for the government to request HS2 Ltd to reassess the impact the construction is having on nature.
The Wildlife Trusts said their investigation took a year to complete.
“As well as the catalog of errors when assessing pre-existing nature, this audit found that HS2 Ltd’s metrics (its ‘accounting tool’ for assessing impacts on nature) are untested, outdated and fundamentally flawed,” they said.
To enable developers to calculate the impact of construction projects on the natural world, features such as streams, hedgerows and woodlands are given values that can be entered into a spreadsheet and accounted for.
The trusts report stated that mature hedges which “provide berries, shelter and nesting places for wildlife” had been given “lower natural value than new hedges” which HS2 Ltd allegedly planted. He said some streams, ponds and trees were “missed from the data.”
Using HS2 Ltd data where possible, the report found that Phase One, which covers 140 miles of track between London and the West Midlands, would cause nearly eight times as much ‘nature loss’ as represented by HS2 Ltd’s calculations .
Phase 2a between the West Midlands and Crewe would result in a 42% nature loss, compared to HS2 Ltd’s forecast of 17%, according to the document.
Dr Rachel Giles of the Cheshire Wildlife Trust and author of the report, said she was shocked by the errors and discrepancies their review revealed.
“HS2 Ltd needs to stop using a deeply flawed method to calculate the value of nature affected by the construction of the path,” he said. “It is surprising that a flagship infrastructure project is able to use a metric that is untested and not fit for purpose.
“HS2 Ltd should urgently recalculate the total loss to nature, reassessing existing biodiversity along the entire route while there is still time to change the scheme design and delivery.”
Tom Oliver, professor of applied ecology at the University of Reading, told the BBC the report was “extremely worrying”.
He said the methodology used by HS2 Ltd was “ten years out of date” and that the organization was “scoring its homework”.
“You can’t go back in time and undo the phase one work that happened, but for phase two the importance of these natural habitats is so great, the extra work in terms of recalculating…it seems like a no-brainer. “
In response to the trusts’ report, a spokesman for HS2 Ltd said the organization “did not acknowledge the figures” or “deem them reliable”.
“The Wildlife Trusts undertook limited desk research and did not have access to large areas of land to undertake ecological surveys, unlike the ecologists who compiled the HS2 data,” the spokesperson said.
They added that it was reviewing its assessment methodology and intended to “align more closely with the government’s biodiversity metric once it is released in the coming months”.
The Trusts said HS2 Ltd should suspend all building and enabling work immediately and the bill authorizing the Crewe to Manchester section of the line should be discontinued. He called on the company to remap existing habitats and recalculate the impact on nature.
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