Advising on carbon-rich soils, deep peat and priority peatland habitat in development management

Purpose

The purpose of this guidance is to help NatureScot staff provide developers, planning authorities and Scottish Government with consistent advice on the effect of wind farms and other renewable energy proposals on peatland habitat. The guidance also sets out the framework within which NatureScot will decide when wind farms and other renewable energy proposals sited on peat raise natural heritage issues of national interest.

Introduction

The guidance describes how we will support the implementation of Scottish Planning Policy (2014) in relation to carbon-rich soils, deep peat and priority peatland habitat and onshore wind development.  We will apply the same approach to all other forms of development.

Our approach aims to:

• encourage development to avoid carbon-rich soils, deep peat and priority peatland habitat and to minimise losses of the highest quality peatland habitat;
• help to mitigate any effects of development on carbon-rich soils, deep peat and priority peatland habitat; and
• ensure no net loss of public benefit through effective restoration and management of damaged bog to compensate for any losses.

Further guidance relevant to developments on peatland is contained in Annex 1.

Policy context

Scottish Planning Policy (SPP) establishes carbon-rich soils, deep peat and priority peatland habitat as nationally important environmental interests:

“Recognising the need for significant protection, in these areas wind farms may be appropriate in some circumstances. Further consideration will be required to demonstrate that any significant effects on the qualities of these areas can be substantially overcome by siting, design or other mitigation” (SPP, Table 1, page 39).

SPP (paragraph 161) requires planning authorities to embody this in spatial frameworks that identify those areas that are likely to be most appropriate for onshore wind farms. We have provided guidance for planning authorities on how to do this in Spatial Planning for Onshore Wind Turbines.

A more detailed and exacting development management process complements the spatial framework (paragraph 163) and paragraph 169 states:

“Proposals for energy infrastructure developments should always take account of spatial frameworks for wind farms and heat maps where these are relevant. Considerations will vary relative to the scale of the proposal and area characteristics but are likely to include (amongst others):

• effect on greenhouse gas emissions;
• impacts on carbon-rich soils, using the carbon calculator; and
• effects on the natural heritage”.

The National Peatland Plan, the 2020 Challenge for Scotland's Biodiversity and its associated  Route Map, the Scottish Land Use Strategy and the Scottish Soil Framework all complement and support the intention of SPP with regard to carbon-rich soils, deep peat and priority peatland habitat and highlight the importance of these resources.

What are carbon-rich soils, deep peat and priority peatland habitats?

Carbon-rich soils are those with any surface organic (peaty or peat) layer.  Peat in the Scottish soil classification is soil with more than 60% organic carbon and exceeding 50cm in thickness. The four peat forming priority peatland habitats defined in the UKBAP are: Blanket Bog, Lowland Raised Bog, Lowland Fens and part of Upland Flushes, Fens and Swamps.

Our Carbon and Peatland Map, published in June 2016, is available on Geo View (Carbon and Peatland 2016 layer) and on Scotland’s soils website which provides detail on how to interpret the map. It identifies the nationally important resource and enables planning authorities to map carbon-rich soils, deep peat and priority peatland habitat in a consistent manner in wind farm spatial frameworks.

The map is a strategic planning tool. It is not a definitive account of where important carbon rich soils, deep peat and priority peatland habitat exist. Development proposals on peat, whether in the mapped area or not, will always require a site-specific and detailed peat and vegetation survey to confirm the quality and distribution of peatland across the site. This information will confirm the extent to which nationally-important peatland will actually be affected by the development, and inform design, micro-siting and mitigation.

When responding to scoping requests we may note whether the proposal is within the mapped area, but we should focus our advice on the actual effects on peatland habitat.

Assessing the impacts of development on carbon-rich soils, deep peat and peatland

SPP affords ‘significant protection’ to carbon-rich soils, deep peat and priority peatland habitat and further consideration will be required to demonstrate that any significant effects on the qualities of these areas can be substantially overcome by siting, design or other mitigation (SPP, Table 1, page 39).

Assessing effects

Wind farms and other developments may have ‘direct’ or ‘indirect’ effects on peat.

• Direct impacts comprise a loss of peatland habitat from the development ‘footprint’ and habitat lost or damaged during construction and operation e.g. due to storage of topsoil/peat on habitat.
• Indirect impacts comprise impacts from either temporary or permanent changes in drainage patterns and the quality or quantity of surface and ground water. Peatland habitats are complex hydrological systems, vulnerable to activities occurring beyond the boundaries of individual habitat patches. Examples of indirect impacts include:
  • down-slope droughting or up-slope flooding of peat-based habitat;
  • the pollution of wetland habitat through accidental spillage of vehicular fuels and oils, and from the deterioration of track surfaces during their usage;
  • reduced stability of peat-based habitat on steep slopes, which in turn may have further impacts on habitat and species should a peat slide event occur.

Determining when effects are significant

Carbon-rich soils, deep peat and priority peatland habitat are in Group 2 of Table 1 in SPP and afforded the same protection (with regard to wind farms) as Natura sites, SSSI and other international and national designations.

A ‘significant effect’ on the qualities of the carbon-rich soils, deep peat and priority peatland habitat is likely to result from:

• The complete loss of the resource (for example by excavation, or by covering the area in concrete)
• The loss of function of the habitat, whereby the peat, or peatland habitat, is likely to be lost or significantly degraded as a result of the development.

When a proposal will have significant effects we should advise of this in our response to the application.  We should also recommend whether further mitigation is required.  However, we will only use an objection when these effects are on peatland habitat which is deemed to be of national interest (see below).

How to respond

Avoidance

The benefits from avoiding areas of good peatland habitat include:

• reduced technical challenges and costs of constructing on deeper peat;
• reduced impact of peat excavation on carbon payback;
• less difficulty of managing excavated peat on construction sites;
• less need for identifying suitable uses for excavated peat.

Our role is to help developers avoid sensitive peatland habitat by designing an appropriate wind farm of the right scale for the site.

Mitigation

Impacts on peatland can be reduced by:

• conducting detailed habitat surveys and peat depth surveys;
• avoiding deeper peat and sensitive habitat;
• adopting alternative construction techniques such as floating roads and piled turbine foundations; and
• carefully planning drainage on the site and ensuring good maintenance of mitigation measures on site.

Compensation: habitat management and enhancement

When potential impacts cannot be avoided or mitigated (for example, through alterations to the site layout or construction techniques), it is good practice to identify opportunities for habitat enhancement. This seeks to improve the condition of existing peatland habitat and to restore damaged habitat.

We should encourage developers to undertake habitat management and enhancement when peatland habitat is lost to development. In some circumstances, where we consider the likely loss of peatland habitat is of national interest, we should use a conditioned objection to ensure that any consent provides adequate compensation for any loss.

Typical compensation measures include:

• tree removal²
• blocking drains/installing dams;
• cessation of burning/peat cutting; and
• reducing grazing and trampling pressures.

Further guidance on habitat management plans is available. Guidance on peatland restoration is available. 

Identifying when impacts may be of national interest

To help determine when a proposal could have a significant effect that is of national interest, we have developed a new assessment framework (see Annex 2 and site visit template). This framework starts from the position that national interest will only arise when peatland of the highest quality is lost or damaged. We want to:

• avoid any further loss of raised and montane bogs;
• minimise the loss of peat-forming blanket bog; and
• ensure no net loss of public benefit through effective restoration and management of damaged bog to compensate for any losses.

Our focus is on peatland habitat. We will not raise national interest matters solely on the carbon implications of new developments, or the impacts on ‘deep peat’.

The framework adopts elements of the criteria used to select SSSIs and uses information collated from the Environmental Statement (mainly in the Ecology chapter and the Geology and Hydrogeology chapter, together with supporting Appendices) complemented by information on GeoView, aerial photography and other relevant data and additional field observations.

Having applied the tests in Annex 2 and concluding that there are significant effects that cannot be substantially overcome, you should consider an objection in line with our National Interest Guidance.  You should seek specialist advice from Habitats Group (Rural Resources Unit) and refer the case to the Area Manager if necessary.

Working with other agencies

When providing advice on the impacts of development on carbon rich soils, deep peat and priority peatland habitat, it is important that we work with other key agencies to align our advice.

• We should liaise with SEPA on issues relating to groundwater dependent terrestrial ecosystems (GWDTEs); hydrology; waste management (such as the treatment of peat excavated during construction) and carbon emissions. 
• We should liaise with FCS where proposals for development, or peatland restoration, may result in woodland removal or have an effect on woodland resources.

Annex 3 shows the topics on which we and SEPA currently lead.

Annex 1. Further guidance

 

Footnotes

1. See Control of woodland removal policy and refer to FCS 

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