Weatherhill Quarry - Nature After Minerals

Weatherhill Quarry is a 116h silica sand quarry situated within the North Pennines SAC / SPA. Following the cessation of extraction works, the operator is obliged to submit a reclamation scheme for the site. Given the sensitive location of the site, Nature After Minerals was asked to provide advice for a restoration scheme that maximises biodiversity, while also extending the internationally-important habitats in the surrounding designated land.

Size

116 ha

Location

Weatherhill Quarry, Durham

Status

Post-extraction

Mineral Type

Silica sand

Proposed restoration

To be confirmed

Potential best practice

Upland moorland creation, buffering Natura2000 sites, natural regeneration, retention of rough landform

Introduction

Weatherhill Quarry is a disused silica sand quarry located near the village of Stanhope, due west of Durham in north-east England, which has been worked since the 1940s. Nature After Minerals worked with the landowners, Natural England and Durham County Council, to identify the best way to manage the quarry’s post-extraction activities.

Weatherhill Quarry map

Opportunities identified by RESTORE

Weatherhill Quarry is within the internationally-designated Pennine Moors Special Protected Area (SPA) for birds, and Special Area of Conservation (SAC) for its upland heaths and mires (Annex 1 priority habitats). The site offers a significant opportunity to create habitats that complement and enhance the adjacent nationally and internationally-important habitats on Stanhope Moor. The site also has the potential to support some red list priority species, including ring ouzel, black grouse, snipe and the globally near threatened curlew (qualifying feature of SPA).

This potential is also highlighted within the National Character Area profile – no.10 North Pennines - within which the site is located. The Statement of Environmental Opportunity (SEO1) states that the NCA should continue to:

“Protect, manage and enhance the moorlands and moorland fringes of the North Pennines, with their internationally important habitats and wildlife, their sense of wildness and remoteness, and the contribution they make to climate mitigation, water quality and availability and water flow”

Why Weatherhill Quarry fitted RESTORE objectives:

Weatherhil quarry is of a significant size (>100ha) and has the potential to buffer and extend the priority habitat types in the surrounding North Pennines SPA/SAC. It also has potential to support a several birds (ring ouzel, black grouse, snipe and curlew) and rare and notable invertebrate species which have undergone significant population declines.

Timetable

October 2012

Site visit with Natural England, Durham County Council and the Croglin Estate, followed up with communications around potential restoration options.

June 2014

Durham County Council planning officer attended a RESTORE demonstration event on Natural Regeneration. From this, NAM was asked to input to the Weatherhill site.

February 2015

NAM submitted restoration advice to Durham County Council.

March 2015

NAM drew up a Restoration and Aftercare Scheme Statement for the Landowner.

Proposed restoration

As part of the conditions of the 2003 Review of Old Mineral Permissions (ROMP), the applicant is required to submit a full reclamation scheme

to the mineral planning authority within 30 months of extraction work discontinuing. No scheme has yet to be confirmed.

Our response and suggestions

The restoration of Weatherhill quarry has the potential to deliver high quality upland moorland, featuring a mosaic of habitat and habitat features, including heathland, acid grassland, scrub, shrub, damp flushes, rocky outcrops and exposures.

NAM is confident that a ‘light touch’ restoration is appropriate at Weatherhill. Leaving the existing landform largely intact and allowing areas of the site to naturally regenerate (supplemented by other heathland establishment techniques where appropriate) will enable the site to develop into high quality habitat, increasing its value to wildlife and potentially providing cost savings.

Our response to the operator and mineral planning authority included a number of recommendations that we felt would enhance the restoration and aftercare, as detailed below:

Landform and Landscape

NAM sees little need for further material re-profiling at Weatherill, with the existing landform featuring excellent topographic variation through the presence of hummocks, hollows, rocky outcrops and cliff faces. Many former mineral sites (such as Threshfield) are left with a variable, undulating landform and as the site is on private land without public access, it represents a low risk in terms of health and safety. Therefore we recommend moving as little material as possible and only where necessary, for safety.

Heathland Establishment

A combination of two or three techniques will likely be appropriate in helping heathland establish at Weatherhill. The use of locally-sourced material will be key to ensuring that target species such as purple moor grass, bilberry, crowberry and cotton grass are present, in addition to heather. Commercial seed should be avoided – it is unlikely to be of local provenance and will create a monoculture of heather, of little conservation value.

We recommended that natural regeneration be a key component of the restoration scheme at the site, retaining patches of bare ground, for the benefit of key species for Durham including: Grayling butterfly, Dingy skipper, Northern brown argus and Chalk carpet moth. Should additional seeding be required, we recommended harvesting heather litter/brash from a nearby mature donor site: potential in collaboration with Natural England utilising the next door SSSI. We discouraged the use of a nurse grass, which should only be used to assist with slope stability and only trialled in small, select areas.

Should a nurse grass be necessary, we recommended that species must have a low nutrient demand (so fertiliser is not required); have short viability (i.e. should die out after three or four years without the need for control) and form a sparse sward to provide space for heathland species to grow.

Cliff Faces, Rocky Outcrops and Exposures

Variations in landform and topography create microhabitats and ecological niches, in which a range of wildlife will thrive. In the wider Pennines landscape, there are limited opportunities to create these upland moorland features and niches which is why Weatherhill is an important site. As such, we recommended retaining faces across various aspects and only battering the quarry faces deemed to be a risk to safety (bearing in mind that this site will not be publically accessible). Should battering be necessary, then we advised leaving any rocky outcrops at the base or the top of the batter exposed. Retaining such features have the potential to be highly beneficial for a number of species including ring ouzel (Turdus torquatus), a priority species that has undergone significant population declines in recent years. This species is found in upland heathland habitat and typically nests in rocky outcrops. More information can be found here.

Wet Flushes and Ponds

NAM recommended retaining the areas where water is collecting naturally and protecting any shallow gulleys that are already present. With time, these could develop into flush systems and, if regularly damp, should benefit curlew and/or snipe and black grouse, if present in the area.

Stored Soils

Any remaining soils stored on site can be re-spread thinly. Depending on the method of storage and length of time stored, they may contain viable heather propagules. Where it is necessary to cultivate land-formed areas, it is recommended to use low ground-pressure equipment to retain the microtopography.

Scrub

Native scrub is an important but under represented component of the wider upland landscape, creating structural diversity and providing shelter and feeding opportunities. There are opportunities to incorporate areas of scrub in the developing habitat mosaic through natural regeneration. The proportion of scrub at 10-20% is significant without dominating the site. Fencing may be required to protect it from browsing early on, and it will need to be maintained by periodic coppicing.

Aftercare and Long-term Management

The site will continue to be managed in the long term by its owner, so its aftercare is secured this way. With management, Weatherhill will develop into an important site, supporting a species-rich upland habitat mosaic appropriate to the wider landscape. Aftercare management should look to develop and maintain vegetation of different ages and structures. Initially, only light intervention is necessary as the habitat establishes. In the longer term, rotational management - through grazing, cutting and/or burning - should ensure there is always bare ground, exposures and pioneer, establishing and mature heathland, grassland and scrub.

How this best practice is transferable

This is an example of how mineral sites can buffer and extend Natura2000 habitats to benefit endangered or notable species of varying taxa. This is a similar approach to that at Schuddebeurze – another RESTORE project site where abandoned quarries are being restored by VLM a Belgian agency.

In the UK a number of quarries have planning permission for extraction which pre-dates designation as a Natura2000 site, a situation likely to also occur across north-west Europe. Natura2000 is considered by some developers as a constraint; restoration here demonstrates how important restored quarry sites can be in extending the priority habitat of these designated sites but that the restoration needs careful consideration in consultation with the appropriate statutory agency and environmental specialists.

Lessons learned

Through our engagement with this site, we have had the opportunity to demonstrate how important mineral restoration sites are in buffering existing Natura2000 sites and extending the habitats for which they are designated. The extraction activities at the site have resulted in some interesting landforms which create a variety of different microhabitat for the benefit of a large suite of species. Such landforms often get ‘smoothed’ out during restoration works, with the false impression that neat is best. This site demonstrates that, should health and safety allow, these more undulating features provide far more valuable features for wildlife.