Supplementary written evidence submitted by Natural England (HSU0002)

It was a pleasure to provide evidence to the House of Commons Transport Select Committee at the session earlier this month to discuss the environmental aspects of the HS2 Project. I agreed to provide some detail in relation to some of the points we discussed and please find that outlined below.

Figures for impacts on Ancient Woodland from temporary works for phase 2b:

We believe that this would be 0.555ha, derived from figures set out in Table 2 of the Woodland Trust’s petition on Phase 2b. (copy of petition enclosed)
Temporary works are listed below, however as you will see, the petition also sets out other areas where design changes could further reduce Ancient Woodland impacts.

Arden House Wood AWI site	Construction of the temporary Ashley railhead and associated road realignment will result in the permanent loss of up to 0.2ha PAWS from Arden House Wood AWI site. A more sensitively-thought out approach to the design of the access road upgrades would avoid these impacts.
Construction of the temporary Ashley railhead, and realigned Mobberley Road and Mobberley Road offline overbridge	will result in the loss of 0.1ha ASNW from East Arden House Wood ancient woodland. HS2 Limited should develop an alternative design based on upgrade of the existing road instead, to avoid the loss of ASNW.
Sugar Brook Wood AW	Construction of the temporary Ashley railhead will result in the loss of up to 0.12ha of Sugar Brook ancient woodland and LWS. Given that the proposed works appear to be temporary, the construction boundary should be amended to exclude the ancient woodland.
Hennersley Bank AWI	Temporary realignment of a section of the M56, and minor utilities work (removal of electricity cables) will result in the permanent loss of up to 0.1ha ASNW from Hennersley Bank AWI site.
Bongs Wood AWI site	Utilities work involving modification of an overhead power line, could lead to loss of up to 0.035ha ASNW.

Natural England’s estimated figures for the costs of Biodiversity Net Gain (BNG) for each phase of the route are as follows:

Biodiversity units (Bu) needed to achieve 10% gain, with costs
Phase	Bu	Costs (£)*
1	2206	55,147,500
2a	788	19,690,000
2b	583	14,575,000
TOTAL		89,412,500

Notes:

Bu requirement is 10% over baseline calculation
Costs are based on average of £25,000 per Bu

Examples of successful mitigation responses to major infrastructure and costs:

Environmental mitigation measures as an element of overall scheme cost are difficult to quantify as the type and level of impact to be mitigated and the geographical location of the scheme will mean each example is site specific. Natural England’s literature review of green bridges [1] includes a section on costs for this mitigation measure which range from £1m - £10m. National Highways indicates that construction of the recently completed A556 green bridge cost in the region of £890,000 with a further £273,000 on ‘greening work’ on the deck.[2]

Large scale bespoke measures such as green bridges and HS2’s bat protection structure at Calvert can come with significant cost but are a) designed to address severe ecological impacts that would otherwise prevent the scheme from proceeding and b) typically a small percentage of overall scheme cost. The costs of ecological habitat planting and long term maintenance will depend on the costs of land purchase and/or on the type of management agreement that secures the land for the required purpose. The BNG costs set out above provide some indication of securing land for ecological habitat purposes for a 30-year period.

Smaller scale mitigation measures such as underpasses, culverts, amphibian or badger tunnels, fencing, come at much lower costs; HS2 Ltd, Network Rail, National Highways may hold useful data on costs for this type of measure. I trust that these additional points prove useful and should you have any queries or require any further information please don’t hesitate to contact me.

November 2022