Monday 13 February 2023

HS2 got its nature figures wrong, new report reveals

HS2 – already plagued with issues – has, according to The Wildlife Trusts, underestimated its impact on habitats and wildlife. 


The charity is urging wildlife lovers to sign this open letter. They claim:
many well established tree-lined and species-rich hedgerows, which provide berries, shelter and nesting places for wildlife, have been given a lower nature value than the new hedgerows that HS2 Ltd is going to plant.
We shouldn’t be surprised. It was the same for Aggregate Industries’ plans for Straitgate Farm, where centuries-old 4m-wide biodiversity-rich hedgerows were valued at 39.92 units, less than their young sapling replacements at 43.19 units

Why did this matter at Straitgate? These units formed part of the Planning Inspectors’ decision:  
85. …there would be a 15% net gain in biodiversity… which would further weigh significantly in favour. 
Devon County Council’s ecology witness said it wasn't clear how these figures had been derived:  
5.7 Subsequent to biodiversity metric offsetting calculations provided in the July 2017 Regulation 22 Ecology Response, SLR submitted a recalculation of Biodiversity Net Gain using the Defra Metric 2.0 tool in January 2021 [CD4.51A] and returned an overall 18.07% increase in habitat units and 8.18% increase in hedgerow units. The report states that the scheme provides an overall net gain in biodiversity units of 15% but it is not clear how this figure has been arrived at based on the headline summary figures from the Metric 2.0 (habitats, hedgerows and riverine habitats are calculated separately). 
Maybe it was smoke and mirrors, maybe it was magic. Whatever it was, the approach of biodiversity net gain clearly trades wildlife losses today for uncertain future gains – with a huge number of mitigation commitments from developers failing to be delivered.