Government must require HS2 Ltd re-evaluate nature loss and compensate fairly, says Herts and Middlesex Wildlife Trust.

A new evidence report, ‘HS2 double jeopardy: how the UK’s largest infrastructure project undervalued nature and overvalued its compensation measures’ reveals fundamental flaws in the way HS2 Ltd has assessed the value of nature along the construction path of HS2.

It finds that HS2 Ltd has hugely undervalued natural habitats and the wildlife that is being destroyed by the construction along the route – while simultaneously overvaluing the impact of its nature compensation measures.

For example, Phase 1 which covers 140 miles of track between London and the West Midlands, will cause at least 7.9 times more nature loss than accounted for by HS2 Ltd. The new analysis finds that HS2 Ltd has hugely undervalued wild places being destroyed along the route – while simultaneously overvaluing the impact of its nature compensation measures.

The route of HS2 will cut a swathe through Hertfordshire and Middlesex, and the Trust’s Broadwater Lake Nature Reserve is being carved in two through construction of the Colne Valley Viaduct, which will be the UK’s longest railway viaduct at 3.4km. Broadwater Lake is an important wildlife haven, and forms part of the Mid-Colne Site of Special Scientific Interest, providing a particularly important refuge for wildfowl which move from other water bodies in the Valley when they are used for recreational purposes. It’s known to support huge numbers of waterbirds and is particularly important for its breeding population of Pochard, a species which is on the national Red List for species of conservation concern. The reserve is a key stepping stone for wildlife moving across the landscape, such as the Daubenton’s Bat. People too are missing out on an opportunity to visit this once peaceful wildlife haven as the site has been occupied by HS2.

The evidence report is a review of the No Net Loss* data for HS2 Phases 1 and 2a and was commissioned by The Wildlife Trusts. It finds:

• Across Phase 1 of HS2 (2021 scheme): at least 7.9 times more biodiversity loss than that calculated by HS2 Ltd
• Across Phase 2a of HS2: at least 3.6 times more biodiversity loss than that calculated by HS2 Ltd

HS2 Ltd promised that nature would not lose out when much-loved natural areas and important habitats were destroyed to make way for construction of the high-speed rail line. It made a commitment to No Net Loss of biodiversity for replaceable habitats along Phase 1 and 2a of the route, and a net gain for biodiversity along Phase 2b.

Compensating for nature losses relies on accurate baseline assessments of the value of wildlife habitats along the route – for example, by looking to see how species-rich the grasslands are or how diverse woodlands are in terms of the mix of native tree species and complexity of woodland structure, the quality of the understorey and woodland floor plants.

The report found watercourses, ponds and trees which have been missed out of the data, and problems with the way nature is being valued. For example, many tree-lined, well established 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.

The new report which is published today finds that HS2 Ltd's No Net Loss metric – their 'accounting tool' for assessing impacts on nature – is untested, out of date and fundamentally flawed. Taking a conservative approach to the data, the report highlights alarming errors in HS2 Ltd’s calculations and mapping, indicative of a large-scale problem, which calls into question the adequacy of all HS2 Ltd’s nature restoration and compensation plans.

• Our Phase 1 calculations show that there will be at least 17% less nature present after construction than there was before building started. HS2 Ltd’s figures say there will only be a 2.6 % nature loss. 

• For Phase 2a, we found that there will be at least 42% less nature present after construction than there was before building started. HS2 Ltd’s figures say there will only be a 17.01% nature loss. 

In summary, a comparison of No Net Loss calculations is as follows:

• For Phase 1 (2021 scheme), Cheshire Wildlife Trust’s assessment indicates a minimum net loss of 4,367 NNL units (17.36% loss of the pre-construction biodiversity value in NNL Units). This compares to a net loss of 555 NNL units (2.60% loss of the pre-construction biodiversity value in NNL units), as calculated by HS2 Ltd.
• For Phase 2a, Cheshire Wildlife Trust’s assessment indicates a minimum net loss of 4,891 NNL units (42.80% loss of the pre-construction biodiversity value in NNL Units). This compares to a net loss of 1,342 NNL units (17.01% loss of the pre-construction biodiversity value in NNL units), as calculated by HS2 Ltd.

As things stand, HS2 Ltd will not compensate sufficiently for the damage likely to be caused by Phases 1 and 2a of the scheme. If HS2 Ltd continues to use the same metric, it will not come close to delivering a Net Gain for Biodiversity for Phase 2b.

Dr Rachel Giles, evidence and planning manager at Cheshire Wildlife Trust and author of the report, says:

Chloë Edwards, Director of Nature Recovery at Herts and Middlesex Wildlife Trust, says:

The Wildlife Trusts’ recommendations:

1. HS2 Ltd should re-map existing habitats along Phases 1 and 2a, correcting mapping errors, applying the correct nature values to habitats, and ensuring no habitats are excluded.
2. HS2 Ltd should recalculate the total impacts to nature, by using an up to date and proven methodology, such as one directly comparable to the government’s current Biodiversity Metric 3.1. If changes to the methodology are made these should be transparent and evidence-based. It is critical that HS2 Ltd ensures all data is made publicly available at the point the figures are released to facilitate transparency and enable independent scrutiny.
3. The Government should respond swiftly to our findings, while there is still time to change the scheme’s design and delivery to limit the adverse impacts and enhance biodiversity in a way that is commensurate with the scale of the damage – by achieving a minimum 10% biodiversity net gain for replaceable habitats for each phase of the scheme.
4. HS2 Ltd should immediately pause all construction and enabling works and halt the passage of the Phase 2b Hybrid Bill whilst these new findings are assessed by the Government.

Read , ‘HS2 double jeopardy: how the UK’s largest infrastructure project undervalued nature and overvalued its compensation measures’ here. The report is based on an investigation by the Evidence and Planning team at Cheshire Wildlife Trust.

Today The Wildlife Trusts have published an open letter to Secretary of State for Transport, Rt Hon Mark Harper, and Secretary of State for the Environment, Rt Hon Thérèse Coffey MP, urging them to work together to address the new evidence about biodiversity loss calculation errors by HS2 Ltd and asking for an immediate pause on construction.