CEMEX UK Operations Ltd
Doveholes Quarry: RoMP Application
DBLC Ltd. Job No. 002.018
November 2012
Explanation of Restoration Techniques
Introduction
Progressive restoration of various areas within the quarry will involve the application of a
number of different techniques, either on their own or in combination to achieve the
successful restoration of Doveholes Quarry.
Some areas have already been worked and partly restored, (such as Tip 4), others have
been fully worked and not restored in any way (such as the western faces and benches in
the Shaw land) and other as yet untouched areas would be worked and restored during the
15 year RoMP period.
It should be noted that Drawing No. DH018: ‘Restoration Types and Associated Areas of
Application’ indicates those areas that will be restored during the RoMP period and the
restoration technique/s that would be applied to each. This document should be read in
conjunction with that drawing in order to gain a better understanding of what is being
proposed.
Published Guidance on Restoration of Hard Rock Quarries
There are two main publications that specifically outline restoration techniques that can be
undertaken within hard rock quarries, as follows:
•
•
‘Secure and Sustainable Final Slopes for SME Aggregate Quarries’ (Ref. 1). (Hereafter referred
to as the SSFS document).
‘Reclamation of Limestone Quarries by Landform Simulation’ (Ref. 2). (Hereafter referred to as
the RLQLS document).
The first of these publications concentrates on the technical aspects of creating final slopes
and restoration landforms within hard rock quarries while the second one, in addition to
consideration of techniques, also includes a number of case studies to assess previous
attempts at restoration by mineral operators over a number of years. Both publications
summarise a series of recommendations that should be applied by operators when planning
new areas of mineral extraction and undertaking restoration operations.
The restoration techniques summarised below are site specific elaborations of the
recommendations contained within the guidance documents and where applicable
references have been included to highlight the aims or value of the technique. This has
occasionally been supplemented by relevant graphics or photographs for the purposes of
emphasis.
In addition to consideration of the published guidance documents above, extensive
discussion with Gary Ellis (Landscape Architect, Derbyshire County Council) regarding
Ref.1: Commissioned by the Mineral Industry Research Organisation (MIRO) and written by The Geoffrey Walton Practice
(Now GWP Consultants LLP) and David Jarvis Associates Limited, published in March 2004
Ref.2: Written by the Environmental Consultancy of the University of Sheffield (ECUS), October 2004.
Ref.3: Twite Management Plan written by Kevin Honour of Argus Ecology. Included with RoMP submission documents.
CEMEX UK Operations Ltd
Doveholes Quarry: RoMP Application
DBLC Ltd. Job No. 002.018
November 2012
appropriate restoration of the site has been undertaken in order to inform the iterative design
process.
The techniques have been presented in roughly the order in which they would be applied to
various areas within the quarry and the timescales have been indicated where appropriate.
Restoration Technique A: Cut/Fill and Placement of Bulk Restoration Material Before
Grading of Soils to Final Levels, Cultivation and Seeding – Tip 4
As part of the initial works during Phase 1 (2013), the northern end of Tip 4 requires material
to be cut from the toe and placed further to the south and also placement of bulk restoration
material excavated and hauled from elsewhere on site to create formation contours at a
similar gradient to the southern slopes of Tip 4 (ie. approximately 1:3 to 1:5). Once the
formation levels are created, soil temporarily bunded on top of Tip 4 would be placed and/or
regraded to final restoration levels and would be seeded to grassland using an appropriate
mix such as the following which has been suggested by Derbyshire Wildlife Trust for the
adjoining Peak Fringe Natural Area. While not specifically designed for the White Peak
area, it includes many of the species growing in the vicinity of Bee Low Quarry, and is
appropriate for all areas to be restored and grassed as part of this RoMP scheme. The mix
includes the following species:
(L=late flowering species)
Grasses 70%
Avenula pratensis Meadow oat grass
Brachypodium pinnatum Tor grass (not a good grazing grass)
Briza media Quaking grass L
Bromus erectus Upright brome
Bromus hordeaceus Soft brome L
Cynosurus cristatus Crested dog’s tail
Festuca ovina Sheep’s fescue
Koeleria macrantha Crested hair grass
Major Herbs 20%
Achillea millefolium Yarrow L
Centaurea nigra Black knapweed L
Lathyrus pratensis Meadow vetchling L
Leontodon hispidus Autumn hawkbit L
Leucanthemum vulgare Ox eye daisy
Lotus corniculatus Common bird’s-foot-trefoil
Plantago lanceolata Ribwort plantain
Ranunculus acris Meadow buttercup
Trifolium pratense Red clover
Vicia sepium Bush vetch
Minor Herbs 10%
Ajuga reptans Bugle
Campanula rotundifolia Harebell L
Carduus nutans Musk thistle
Ref.1: Commissioned by the Mineral Industry Research Organisation (MIRO) and written by The Geoffrey Walton Practice
(Now GWP Consultants LLP) and David Jarvis Associates Limited, published in March 2004
Ref.2: Written by the Environmental Consultancy of the University of Sheffield (ECUS), October 2004.
Ref.3: Twite Management Plan written by Kevin Honour of Argus Ecology. Included with RoMP submission documents.
CEMEX UK Operations Ltd
Doveholes Quarry: RoMP Application
DBLC Ltd. Job No. 002.018
November 2012
Cruciata laevipes Crosswort
Fragaria vesca Wild strawberry
Galium verum Lady’s bedstraw
Linum catharticum Purging / Fairy flax
Medicago lupulina Black medick
Origanum vulgare Marjoram L
Plantago media Hoary plantain
Primula veris Cowslip
Ranunculus bulbosus Bulbous buttercup
Sanguisorba minor Salad burnet
Thymus praecox Wild thyme
Trifolium medium Zig zag clover
Vicia sativa Common vetch
This mix is also considered beneficial for Twite, although the Twite Management Plan (Ref.3)
suggests a number of other seed bearing species that are important, as outlined in the
following passage from the Plan:
‘Twite feed exclusively on seeds. Unlike other seed eating birds which feed their young on
invertebrates, twite regurgitate a seedy soup for their young (Young, 2009). This means a constant
supply of seeds is required throughout the breeding period. Dandelions (Taraxacum sp.) are
important at the beginning of the breeding season, although twite have been seen to feed on coltsfoot
(Tussilago farfara) on the floor of Bee Low (Melling, pers. com). Common sorrel (Rumex acetosa) and
annual meadow grass (Poa annua) have been shown to be very important to twite mid-summer
(McGhie et al, 1994), followed by autumn hawkbit (Leontodon autumnalis) and thistles (Cirsium sp.),
which are the main sources of seeds for twite at the end of the season.’
It is envisaged that the exact mix chosen will be selected at the time of cultivation and
spreading based on the above information.
The Tip 4 area to be restored is shown on Drawing No. DH008: ‘Detailed Restoration
Proposals for Tip 4 Restoration Details: End 2013’.
Restoration Technique B: Hydro-Seeding of Northern Middle Slopes on Tip 4
The Landscape and Visual Impact Assessment has identified that the unrestored northeast
flank of Tip 4 represents a negative amenity impact in its current condition. As a result it is
proposed to restore the upper part of the visible face of the landform very early in the
quarry’s continued development. The lower portion of this visible face does not lend itself to
early restoration employing traditional techniques however due to limited access and
steepness of gradient.
The lower level of Tip 4 is proposed to be restored over a longer timeframe utilising dried silt
from the quarry floor (described in more detail below). There is, however, insufficient
material to create a restored landform contiguous with the early stage restoration. Given this
and the above it is proposed to restore the visible mid-flank in parallel with the upper flank
employing a hydro-seeding technique.
Ref.1: Commissioned by the Mineral Industry Research Organisation (MIRO) and written by The Geoffrey Walton Practice
(Now GWP Consultants LLP) and David Jarvis Associates Limited, published in March 2004
Ref.2: Written by the Environmental Consultancy of the University of Sheffield (ECUS), October 2004.
Ref.3: Twite Management Plan written by Kevin Honour of Argus Ecology. Included with RoMP submission documents.
CEMEX UK Operations Ltd
Doveholes Quarry: RoMP Application
DBLC Ltd. Job No. 002.018
November 2012
Hydro-seeding is the process by which a slurry consisting of grass seed, fibre mulch,
fertiliser, and a sticking agent is transported to the area to be seeded in a tank mounted on a
truck and sprayed onto the land surface through a hose by a high powered pump. The
advantages of such a seeding method include its speed of application over a large area, its
effectiveness in seeding areas otherwise not easily accessible, (as at Doveholes), and its
generally quick germination rates due to the fact that the fibre mulch maintains moisture
around the seeds along with the fertiliser adding nutrients. The grass seed to be used in the
mulch would be as specified above under Technique A.
Restoration Technique C: Tipping of Fine Restoration Material Mixed With Suitable
Grass Seed Onto Previously Worked Benches
Some previously worked areas such as the western benches and faces above Shaws Land
cannot be accessed because the benches are too narrow to allow vehicles onto them and/or
access to those benches has been severed. In order to restore these benches, fine
restoration material would be tipped from the top edge of the quarry in order to accumulate
within the unevenness of the faces and also on the benches themselves. To assist the
restoration process, a grass seed mix (as specified under Technique A) would be mixed with
the fines material prior to placement.
Restoration Technique D: Creation of Rollover Slope at Crest of Quarry
The first ‘new’ area to be worked as part of the RoMP development would be the ‘triangle
area’ along the eastern edge of the quarry. It therefore provides the opportunity to carefully
plan how the area would be worked and restored, rather than applying techniques once the
majority of extraction and/or previous restoration operations has already taken place (ie.
techniques A to C above).
Through progressive working and restoration operations, a rollover slope would be created
that would, once in place, generally completely hide the upper two faces and in the process
help to visually bring the surrounding landscape down into the quarry. The rollover slope
would be created in the following manner, explained in simple diagrammatic form:
Ref.1: Commissioned by the Mineral Industry Research Organisation (MIRO) and written by The Geoffrey Walton Practice
(Now GWP Consultants LLP) and David Jarvis Associates Limited, published in March 2004
Ref.2: Written by the Environmental Consultancy of the University of Sheffield (ECUS), October 2004.
Ref.3: Twite Management Plan written by Kevin Honour of Argus Ecology. Included with RoMP submission documents.
CEMEX UK Operations Ltd
Doveholes Quarry: RoMP Application
DBLC Ltd. Job No. 002.018
November 2012
The above diagram along with a plan view of the rollover slope design and a 3D computer
generated image of how the rollover slope would look is shown on Drawing No. DH009:
‘Triangle Area – Proposed Rollover Slope Restoration (at end of 2014 - Phase 2)’. The
rollover slope would continue above the upper crest of the quarry and merge with the
existing edge bund (or into a new edge bund that would be created, if needed) which would
separate the slope from the adjacent access track.
The slope would be formed by a series of restoration blasts – firstly along the upper edge of
the quarry (to bury the first face) and then along the first bench (to bury the second face).
The slope would settle at its safe angle of repose which is approximately at a gradient of 1:2.
Following this, a depth of approximately 300 - 500mm of suitable OB material and/or soil
would be placed onto the blasted rollover slope either by excavator placement from below or
tipping from above. An appropriate grass seed mix (as specified under Technique A) would
be applied at the recommended rate after soil placement, either by conventional means or
possibly by hydro-seeding, if considered necessary.
The intention is to apply this rollover slope restoration technique for all permanent faces
formed during the fifteen year development period where these are visible external to the
quarry which would allow enough space at the upper crest to blast the edge back to create
the first part of the rollover slope and hide the first face. Subsequent working in line with the
diagram above would then create the second part of the rollover slope. All future working
areas that are suitable for this type of restoration technique have been identified on Drawing
No. DH018: ‘Restoration Types and Associated Areas of Application’
The effectiveness of introducing rollover slopes along upper quarry faces is discussed on
page 182, (RLQLS document, Ref.2) as follows:
Ref.1: Commissioned by the Mineral Industry Research Organisation (MIRO) and written by The Geoffrey Walton Practice
(Now GWP Consultants LLP) and David Jarvis Associates Limited, published in March 2004
Ref.2: Written by the Environmental Consultancy of the University of Sheffield (ECUS), October 2004.
Ref.3: Twite Management Plan written by Kevin Honour of Argus Ecology. Included with RoMP submission documents.
CEMEX UK Operations Ltd
Doveholes Quarry: RoMP Application
DBLC Ltd. Job No. 002.018
November 2012
‘A combination of landforms and restoration techniques is likely to be the most acceptable
solution for a whole quarry. .... the application of ‘roll over’ along the highest bench and the
introduction of grass or tree covered slopes above buttress/headwall formations is likely to have the
greatest effect in creating a more appropriate and less visually obtrusive restored quarry’.
Finally, the photographs below help to illustrate how this restoration technique can be
applied in practice. Plate 1 shows how an upper face at Dene Quarry has been fully covered
by a rollover slope similar to the type that would be introduced at Doveholes. Plate2 shows
an old restored quarry face very close to Doveholes quarry and how rollover slope creation
in combination with breaking up the angular shape of crests of faces (refer to technique F,
below) can be visually quite effective.
Plate 1: Rollover Slope at Dene Quarry
Ref.1: Commissioned by the Mineral Industry Research Organisation (MIRO) and written by The Geoffrey Walton Practice
(Now GWP Consultants LLP) and David Jarvis Associates Limited, published in March 2004
Ref.2: Written by the Environmental Consultancy of the University of Sheffield (ECUS), October 2004.
Ref.3: Twite Management Plan written by Kevin Honour of Argus Ecology. Included with RoMP submission documents.
CEMEX UK Operations Ltd
Doveholes Quarry: RoMP Application
DBLC Ltd. Job No. 002.018
November 2012
Plate 2: Old Restored Face Close to Doveholes Quarry
Restoration Technique E: Restoration Blasting (Plus OB/Soil Placement) to Create
Restoration Slopes part Way up the Face or to Extend Across Two Benches
Restoration blasting is a technique which has come in for some criticism in the publications
referred to above due in part to its unpredictable nature regarding resultant slope angle
(often too shallow), large size of scree blocks and unstable adjacent faces. It has also been
observed that the landscape context of very large quarries such as Doveholes is very
different from the far narrower, often ‘V’ shaped dale-side landforms that have developed
naturally over many centuries.
Therefore, the scale of some of the restoration techniques applied should be related to the
scale of the quarry itself, and not based on attempts to exactly replicate those features seen
on natural dale-sides. With regard to restoration blasting, whilst not a precise method to
reduce the engineered appearance of quarry benches and faces, it can nonetheless help to
reduce adverse impacts as stated on page 183 (RLQLS document, Ref.2), as follows:
‘It will not be possible to create landforms that appear to be completely natural but it will be possible to
improve the application of restoration blasting to create landforms that appear more natural and
acceptable within the landscape setting’.
As stated above under technique D, there are areas which are yet to be worked that will be
restored by creating a rollover slope to completely hide the upper two faces. However, in
addition to this technique, it is proposed to restore the third and fourth faces by similar
Ref.1: Commissioned by the Mineral Industry Research Organisation (MIRO) and written by The Geoffrey Walton Practice
(Now GWP Consultants LLP) and David Jarvis Associates Limited, published in March 2004
Ref.2: Written by the Environmental Consultancy of the University of Sheffield (ECUS), October 2004.
Ref.3: Twite Management Plan written by Kevin Honour of Argus Ecology. Included with RoMP submission documents.
CEMEX UK Operations Ltd
Doveholes Quarry: RoMP Application
DBLC Ltd. Job No. 002.018
November 2012
blasting operations that would create a c. 1:2 gradient restoration slope that would come part
way up the face, but the upper part of the face would remain visible.
Blasting depths and locations would be designed to create slopes that are interspersed with
remnant buttresses that introduce irregularity and sinuousness into the generally angular
post-extraction face/bench landform.
In addition, in order take account of the large scale of the wider quarry itself, blasting (and
possibly supplementary placement of bulk restoration material) in some areas would attempt
to create slopes that extend across two benches so that some intermediate benches
disappear altogether (subject to safety constraints). The intended effect of this type of
restoration is shown in Figure 5.6 on page 192, (RLQLS document, Ref.2) and as reproduced
below:
Points 7, 9, 10 and 11 of the Executive Summary (RLQLS document, Ref.2) recommend the
following, which would be applied at Doveholes as far as possible:
‘7. Slopes should be continuous and rectilinear, and run along significant lengths of landform. This will
require large volumes of limestone to be blasted along continuous lengths of rock face. Isolated blasts
between buttresses that create isolated slopes should, in most situations, be avoided.
9. Potential modifications to the blasting technique by using lower velocity explosives to produce
headwalls and buttresses that appear less shattered should be considered.
10. Where possible rock faces should be scaled after blasting to remove shattered rock. It should be
observed whether this makes the rock appear more stable and naturally weathered.
Ref.1: Commissioned by the Mineral Industry Research Organisation (MIRO) and written by The Geoffrey Walton Practice
(Now GWP Consultants LLP) and David Jarvis Associates Limited, published in March 2004
Ref.2: Written by the Environmental Consultancy of the University of Sheffield (ECUS), October 2004.
Ref.3: Twite Management Plan written by Kevin Honour of Argus Ecology. Included with RoMP submission documents.
CEMEX UK Operations Ltd
Doveholes Quarry: RoMP Application
DBLC Ltd. Job No. 002.018
November 2012
11. Potential modifications to the blast design to create smaller scree block size should be
considered’.
An example of where restoration blasting and subsequent OB/soil placement and seeding
has achieved a fair amount of success is shown on Plate 5.2 (part of Chapter 5, RLQLS
document, Ref.2) which is reproduced below for information purposes:
In addition, Plate 3 below shows how this restoration technique has been successfully
applied at Dene Quarry, close to Doveholes Quarry:
Plate 3: Restoration Slopes part Way Up Faces at Dene Quarry
Ref.1: Commissioned by the Mineral Industry Research Organisation (MIRO) and written by The Geoffrey Walton Practice
(Now GWP Consultants LLP) and David Jarvis Associates Limited, published in March 2004
Ref.2: Written by the Environmental Consultancy of the University of Sheffield (ECUS), October 2004.
Ref.3: Twite Management Plan written by Kevin Honour of Argus Ecology. Included with RoMP submission documents.
CEMEX UK Operations Ltd
Doveholes Quarry: RoMP Application
DBLC Ltd. Job No. 002.018
November 2012
While acknowledged as not perfect, the buttress and slope/headwall effect created by
restoration blasting/material placement in this instance was agreed by contributors to the
study to be generally quite successful and better than just leaving the face and bench as
they were after stone extraction. However, the difficulties in creating effective restored
landforms through blasting are illustrated by the following two images (Figs 4.3 and 4.4) in
Chapter Four: ‘General Approaches to Slope Treatment’ in the SSFS document Ref.1:
Ref.1: Commissioned by the Mineral Industry Research Organisation (MIRO) and written by The Geoffrey Walton Practice
(Now GWP Consultants LLP) and David Jarvis Associates Limited, published in March 2004
Ref.2: Written by the Environmental Consultancy of the University of Sheffield (ECUS), October 2004.
Ref.3: Twite Management Plan written by Kevin Honour of Argus Ecology. Included with RoMP submission documents.
CEMEX UK Operations Ltd
Doveholes Quarry: RoMP Application
DBLC Ltd. Job No. 002.018
November 2012
If possible and in selected areas, restoration material/fines and possibly soil would be spread
along the edge of the bench prior to blasting, so that once the resultant blast slope is
created, the material would have mixed with the scree, lodged in cracks and crevices and
generally been spread about the slope. In this way, it would prevent the need to
subsequently place or tip this material onto the scree slope by mechanical means. Preseeding the restoration material could be an option as well, using the mix specified under
technique A.
It should be noted though that this type of ‘pre-spreading’ of restoration material onto
benches to be blasted would be initially trialled and assessed to see if it was successful
enough to warrant further application in other parts of the quarry.
Restoration Technique F: Crest Nibbling or Shallow Blasting to Introduce Irregularity
The crests of faces tend to be left very angular and uniform due to efficient modern
extraction techniques and it is the intention of restoration works to effectively try to reverse
this and introduce irregularity to help break up and soften the appearance of faces
themselves and in particular the top crest.
This can be achieved by removing the sharp crest by mechanically ‘nibbling’ it away so that
it then has more of a less rectilinear, more varied appearance. A similar effect can be
achieved by shallow blasting at variable depths (approx. 0.5 – 1.5m depth) along the crest
with the distance from the crest varied from approximately 0.5m to 1.5m.
The effectiveness of crest nibbling is outlined in illustrative form on Figure 5.8 on page 193,
(RLQLS document, Ref.2) and as reproduced below:
Ref.1: Commissioned by the Mineral Industry Research Organisation (MIRO) and written by The Geoffrey Walton Practice
(Now GWP Consultants LLP) and David Jarvis Associates Limited, published in March 2004
Ref.2: Written by the Environmental Consultancy of the University of Sheffield (ECUS), October 2004.
Ref.3: Twite Management Plan written by Kevin Honour of Argus Ecology. Included with RoMP submission documents.
CEMEX UK Operations Ltd
Doveholes Quarry: RoMP Application
DBLC Ltd. Job No. 002.018
November 2012
Shallow blasting at variable depths is illustrated on Figure 6.24 in Chapter 6: Specific
Techniques within the first publication referred to above (Ref.1), and as reproduced below:
In addition, the RLQLS document, Ref.2 states at point 6 in the Executive Summary the
following, which summarises how a combination of crest nibbling/shallow blasting and
subsequent placement of OB/soil material on the rounded/nibbled crests can be effective
The tops of buttresses/headwalls should be mechanically broken up and rounded off after blasting,
and/or by drilling and blasting, to a shallow depth close to the crest after the main restoration blast.
This should be combined with spreading a suitable growing medium on the tops of the rounded
buttresses/headwalls and covering with grass or trees. This will soften the visually obtrusive crest of
the quarry terraces and simulate the rounded tops of buttresses/headwalls in natural dalesides. It
might also improve safety by providing a gradual transition to the vertical face, which will inform
people that they are approaching the edge.
Restoration Technique G: Scrubby Tree and Shrub Planting on Lower Benches
While it is not considered appropriate to introduce extensive woodland planting across
higher areas such as on the top or upper sides of Tip 4, scrubby planting on lower benches
Ref.1: Commissioned by the Mineral Industry Research Organisation (MIRO) and written by The Geoffrey Walton Practice
(Now GWP Consultants LLP) and David Jarvis Associates Limited, published in March 2004
Ref.2: Written by the Environmental Consultancy of the University of Sheffield (ECUS), October 2004.
Ref.3: Twite Management Plan written by Kevin Honour of Argus Ecology. Included with RoMP submission documents.
CEMEX UK Operations Ltd
Doveholes Quarry: RoMP Application
DBLC Ltd. Job No. 002.018
November 2012
and restoration slopes, close to the eventual base of quarry lake level would be
characteristic of other, lower, dale-sides in the surrounding area.
Extraction operations during the 15 year RoMP period would open up some areas which
would be suitable for this restoration approach, possibly in combination with restoration
technique E: slope creation by blasting and OB/soil placement. Material would be placed
either straight onto the bench or on the restoration slope to sufficient depth (min. 300mm) to
enable tree/shrub planting with suitable species to be agreed with the MPA.
The aim of the planting would be to create large enough areas of vegetation to help mitigate
against the visual effects of a large water body that will eventually form in the base of the
quarry. This lake would not form until well beyond the RoMP period, but establishing the first
planting blocks in suitable areas over the next 15 years would benefit the overall site
restoration scheme.
The planting would also help to screen some of the lower faces which would be at least
partly visible from higher locations on land surrounding the quarry. Plate 4 below illustrates
this type of restoration approach
Plate 4: Planting on Lower Areas Adjacent to Water Body – Old Quarry Area to the
Immediate South West of Doveholes Quarry
Ref.1: Commissioned by the Mineral Industry Research Organisation (MIRO) and written by The Geoffrey Walton Practice
(Now GWP Consultants LLP) and David Jarvis Associates Limited, published in March 2004
Ref.2: Written by the Environmental Consultancy of the University of Sheffield (ECUS), October 2004.
Ref.3: Twite Management Plan written by Kevin Honour of Argus Ecology. Included with RoMP submission documents.
CEMEX UK Operations Ltd
Doveholes Quarry: RoMP Application
DBLC Ltd. Job No. 002.018
November 2012
Summary
Progressive restoration of Doveholes quarry will require the application of a range of
techniques, both in the short term and longer term, in order to reduce impact on visual
amenity and help integrate the quarry with the surrounding landscape. The detailed
implementation of the restoration techniques described above will take account of local
landscape character and conditions, geotechnical restraints and safety considerations. How
such factors are accommodated in practical terms will be discussed and agreed with
representatives of the MPA at an annual restoration review meeting. Such a meeting is
proposed by the Company as part of its RoMP submission.
Ref.1: Commissioned by the Mineral Industry Research Organisation (MIRO) and written by The Geoffrey Walton Practice
(Now GWP Consultants LLP) and David Jarvis Associates Limited, published in March 2004
Ref.2: Written by the Environmental Consultancy of the University of Sheffield (ECUS), October 2004.
Ref.3: Twite Management Plan written by Kevin Honour of Argus Ecology. Included with RoMP submission documents.