Protection of Great Crested Newts on HS2 when using trackway

Background and industry context

Trackway, bog mats and ground protection matting (hereafter collectively referred to as trackway) are used on development schemes at locations with accessibility challenges, such as places where the habitat is not suitable for plant and vehicles (e.g. water-logged grassland or bare earth) or to provide a level of temporary habitat protection, reducing the overall time to reinstatement (e.g. temporary access across agricultural land). Trackway is only intended to be a temporary measure, in use for a maximum of 12 months. Figures 1, 2 and 3 show an example of damage caused when no trackway is used, sample trackway and bog mats.

Whilst trackway is an important tool, it does have its challenges. Notably, it can provide a refuge for Great Crested Newts and other fauna, which are then at risk of harm when the trackway moves, as vehicles pass over it or as its adjusted or removed. There is also a risk of entombment if Great Crested Newts are underneath the trackway and the edges of the trackway are subsequently sealed causing the Great Crested Newts to be trapped.

Great Crested Newts often take daily refuge under rocks, logs and discarded debris, where invertebrates collect, and so sheltering in these locations provides food as well as protection from predators and extremes of weather. Trackway can offer similar foraging and sheltering opportunities as these naturally occurring sources of refuge, and so can be attractive to Great Crested Newts (as shown in Figure 4) and other fauna.

Approach

Trackway has been used on HS2, particularly during the Phase One Enabling Works and Phase 2a Ground Investigation and Early Environmental Works, at locations with accessibility challenges or to provide a level of temporary habitat protection, and several good practices and lessons learnt have been identified and captured in the process, which are outlined below. They will be applied to future HS2 works to minimise the risk of Great Crested Newts being harmed by trackway and will also be of use to future projects.

The good practice and lessons learnt whilst using trackway on HS2 are broken down by the following key areas: risk assessment, and methods, including minimising the use and duration of trackway, habitat manipulation, provision of alternative optimum refugia, sealing of trackway edges, regular monitoring of trackway, and trackway removal techniques.

Risk assessment

Great Crested Newts (GCN) are legally protected from killing, disturbance, injury, and capture without a licence^[1]. Where trackway is to be employed a suitably experienced ecologist should provide a clear risk assessment to the Contractor which evaluates the probability of the work resulting in an offence with respect to GCN. The risk assessment should include an evaluation of:

• The quality of the ponds with respect to GCN and their proximity to the proposed trackway e.g. good aquatic habitat and connective terrestrial habitat within 250m of the trackway location.
• The habitat that the trackway will cross with respect to GCN e.g. does the trackway cross probable migration habitat between aquatic and terrestrial habitat. Will the installation of trackway provide a good refuge for GCN.
• The extent of trackway, how long the trackway will be in place, and at what time of year. The longer the trackway is in situ the more likely it will provide a refuge for GCN, if trackway is laid immediately prior to hibernation period there is a higher risk of GCN using trackway as hibernacula (i.e. locations that afford them protection from winter conditions).

If on the basis of this risk assessment, GCN are considered likely to be killed, injured, disturbed, or there is a need to capture them to move them out of harm’s way then a Method Statement under the HS2 Organisational Great Crested Newt Licence should be sought and approved.

Method Statements need to be approved by Ecology Managers at HS2 prior to works commencing. If there are significant changes on site or to programme (such as the proximity of the trackway to ponds, the habitat that the trackway will cross, the extent of the trackway, the duration of the trackway, the time of year that the trackway will be in place etc), then the risk assessment needs to be reviewed and an amendment to the Method Statement may be required (to capture the changes, and the amended Method Statement would need to be approved by Ecology Managers at HS2).

Methods

The following methods should be considered good practice to minimise the risk of GCN being harmed by trackway. These do not necessarily exclude the requirement for a licence for the activity:

• Minimising the use and duration of trackway – in GCN high risk zones, particularly during the spring/autumn migratory period.
• Habitat manipulation – where the trackway will be laid to discourage colonisation of the trackway. This can include strimming habitat down to ground level 2m either side of where the trackway is to be installed.
• Provision of alternative optimum refugia – adjacent to the site to encourage occupancy elsewhere.
• Sealing of trackway edges – in order that GCN and other fauna cannot get under the trackway.
  • Topsoil (compacted) and sandbags have been used to seal trackway (see Figures 5 and 6). However, this should be considered on a case-by-case basis as this could encourage GCN to take refuge or could lead to entombment of GCN under the trackway. For example, where sandbags were used on Phase 2a it was found that they were easily damaged by wildlife and vehicles, and they were subject to shifting due to settlement/vehicle movement on trackway creating gaps for wildlife access.
  • The best sealing material has been heavy duty rubber mats on flat ground along edges which weigh trackway down (more expensive than sandbags/topsoil).
  • Trackway to be sealed immediately following installation. If left overnight there is a risk that GCN may be underneath and may become entombed.
  • If sealed and trackway becomes damaged and/or gaps appear, sealing the trackway again may risk entombing GCN underneath.
  • Ensure trackway is maintained and regularly monitored (monitoring periods to be defined by the Accredited Agent (who is a HS2 Contractor ecologist approved to work under the HS2 Organisational Great Crested Newt Licence) so no gaps appear. Especially important during periods of warm weather when soil bunds can crack, or heavy rain which can wash topsoil away.
• Optimum trackway – to reduce impact on amphibians this is a rubber track with flush edges. Larger panels are considered better on flat ground than smaller panels as they do not flex as much when vehicles pass over them, which could lead to harm to GCN. Smaller panels may be more appropriate for undulating ground. Sub-optimal trackway (from an amphibian perspective) such as bog matting and aluminium panels provide a larger number of gaps/cracks suitable for amphibian refugia/hibernacula and ideally should not be used in high risk areas.
• Use a competent trackway provider – to reduce risk of GCN and other fauna getting under trackway ensure the site is level prior to putting the trackway down and use a competent trackway provider to ensure panels are fixed and adjoined correctly and gaps that GCN can exploit are minimised.
• Removing trackway – remove trackway in one single vertical lift rather than dragging the panel. A grab claw may be required for this. This should be undertaken during the GCN active season, in appropriate weather conditions where night time temperatures are consistently above 5 degrees.
• Removing bog mats – remove bog mats with lifting chains rather than lifting forks. Lifting forks potentially create a downward force and/or shunt. Lifting chains provide a greater level of control.
• Monitoring – an Accredited Agent to monitor installation, maintenance works, and removal works under the Method Statement. If GCN are encountered, then they can be moved by the Accredited Agent to suitable safe location away from the working area, to be agreed upon prior to the works.

Learnings and recommendations

Due to the scale and opportunities offered by HS2, a number of the lessons learnt came about through trialling different approaches and methodologies and identifying the optimum solution. An example is the sealing of trackway edges, where we tried compacted topsoil, sandbags and heavy duty rubber mats on flat ground along edges, and found that the latter was best.

Involving suitably experienced staff and competent providers throughout the process – including the design, planning, installation, maintenance, and removal stages – is key.

Raising awareness amongst the wider workforce of the risk of harm to GCN and other fauna by trackway is also recommended, including through standard methods such as toolbox talks (see Supporting Materials), and more innovative methods like hands-on ecology training for operatives. For example, operatives were given a range of simulated ecological and environmental issues to respond to and scored on their actions/ability to correctly follow procedure. This included a simulated visit to site by regulatory officers and incidents involving the discovery of GCN.

Conclusion

This document outlines good practice and lessons learnt during the Phase One Enabling Works and Phase 2a Ground Investigation and Early Environmental Works on the use of trackway and GCN. By trialling different approaches/methodologies, the key outcomes and recommendations are:

• Carry out a clear risk assessment;
• Implement the good practice methods identified;
• Involve suitably experienced staff and competent providers throughout; and
• Educate the wider workforce.

These lessons will help future HS2 work and other development schemes to minimise the risk of GCN being harmed by trackway.

Acknowledgements

Contributors: former HS2 Ecology Manager Jo Rathbone, HS2 Contractors LMJV, Fusion and Balfour Beatty and their supply chains, and Wood working on behalf of National Grid.

References

[1] Great created newts: protection and licences. Natural England (October 2014). Accessed 23 July 2024.

Supporting materials

Example of a Great Crested Newt Toolbox Talk from Balfour Beatty and their supply chain.