The company building the controversial HS2 rail 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 missed trees, ponds and hedges from maps.
It said the method used to calculate the project’s biodiversity impact was “fundamentally flawed”.
HS2 Ltd said the trusts’ report was “not reliable”.
The trusts are calling for construction to cease and for the government to require HS2 Ltd to re-evaluate the impact of construction on the natural environment.
The Wildlife Trusts said their investigation took a year to complete.
“In addition to the catalog of errors in assessing pre-existing nature, this audit found that HS2 Ltd’s measure (its ‘accounting tool’ for assessing impacts on wildlife) is untested, outdated and fundamentally flawed,” they said.
For developers to calculate the impact of construction projects on the natural world, features such as streams, hedges and forests are given values that fit into a spreadsheet and can be taken into account.
The trusts’ report said mature hedges that “provide berries, shelter and nesting sites for wildlife” had been given “a lower conservation value than the new hedges” that HS2 Ltd would plant. It said some watercourses, ponds and trees were “missed from the data”.
Using HS2 Ltd’s data where possible, the report found that phase one, covering 140 miles of track between London and the West Midlands, would cause “nearly eight times more wildlife loss” than HS2 Ltd’s calculations.
Phase 2a between the West Midlands and Crewe would result in a wildlife loss of 42%, compared to HS2 Ltd’s forecast of 17%, according to the document.
Dr. Rachel Giles of Cheshire Wildlife Trust and author of the report said she was shocked by the errors and discrepancies their audit revealed.
“HS2 Ltd must stop using a deeply flawed methodology to calculate the value of wildlife that has been affected by the construction of the route,” she said. “It is astonishing that a flagship infrastructure project can use a benchmark that has not been tested and is not fit for purpose.
“HS2 Ltd urgently needs to recalculate the total loss to wildlife by re-evaluating existing biodiversity along the entire route while there is still time to change the design and implementation of the scheme.”
Tom Oliver, professor of applied ecology at the University of Reading, told the BBC the report was “hugely concerning”.
He said the methodology used by HS2 Ltd was “ten years out of date” and the organization was “marking its own homework”.
“You can’t go back in time and undo the work of phase one, but for phase two the importance of these natural habitats is so great that the extra work in terms of recalculation … seems like a good idea.”
Responding to the trusts’ report, a spokesperson for HS2 Ltd said the organization “did not recognize the figures” nor “believed them to be reliable”.
“The Wildlife Trusts have done limited desk research and have been denied access to large areas of land for ecological research, unlike the ecologists who collected the data from HS2,” the spokesperson said.
They added that it was reviewing its assessment methodology and planned to “align more closely with the government’s biodiversity measure once it is published in the coming months.”
The Trusts said HS2 Ltd should immediately halt all construction and facility work, and the bill authorizing the Crewe to Manchester section should be halted. It called on the company to remap existing habitats and recalculate the impact on wildlife.
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