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Glyn Rhonwy Pumped Storage Development Consent Order
Appendix 7.3 Gritten Ecology (2012a) Glyn Rhonwy Addendum to Botanical Surveys August 2012
Glyn Rhonwy Pumped Storage Development Consent Order
Final Environmental Statement Volume 3
September 2015
Glyn Rhonwy Pumped Storage Development Consent Order
Final Environmental Statement Volume 3
September 2015
This Appendix was previously submitted as part of the 2012 Environmental
Statement. Where there are references to Quarry Battery Company (QBC), this now
relates to Snowdonia Pumped Hydro (SPH) as this Appendix is submitted in support
of the Development Consent Order (DCO) application.
Glyn Rhonwy Pumped Storage Development Consent Order
Final Environmental Statement Volume 3
September 2015
1
GLYN RHONWY
ADDENDUM TO
BOTANICAL SURVEYS
Dr Rod Gritten PhD PGCE CBiol MSB
GRITTEN ECOLOGY
August 2012
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1.0 INTRODUCTION
The Quarry Battery Company require additional Phase 1 and Phase 2
botanical surveys of various options for temporary construction compounds , the
pipeline route from Quarry Void 6 (QV6) down to Llyn Padarn and for the proposed
pump house on the shores of the Lake. Surveys of all these sites were conducted on
17th
August 2012. During the botanical surveys, any signs of the presence of
Protected Species was also noted (Badgers (Meles meles), Otters (Lutra lutra), Water
Voles (Arvicola terrestris), bats and birds). The three temporary construction site
options at the far western (upper) end of the site will be dealt with first.
2.0 TEMPORARY CONSTRUCTION COMPOUNDS: UPPER SITES
2.1 Option 1
Descriptions of all the additional sites surveyed relate to Map 1 below.
Map 1: Site of proposed temporary construction compounds, pipeline route from
Quarry Void 6 (QV6) and pump house on the shores of Llyn Padarn.
Option 1 is located in a small parcel of mature coniferous forestry dominated
by Sitka Spruce (Picea sitchensis). Many of the trees have recently lodged due to
high wind exposure. Typically, the flora beneath the trees is highly impoverished due
to the acidic nature of the conifer needle ground cover and the lack of light
penetration. A few ferns were noted in one of the clearings created by lodging,
notably Dryopteris dilatata, Blechnum spicant and Polypodium vulgare. Other
species noted were the graminoids Molinia caerulea, Deschampsia flexuosa, Lolium
perenne and Agrostis vinealis with Vaccinium myrtillus, Carex binervis, Erica
cinerea, Digitalis purpurea and Juncus effusus. However, the main plant interest able
to survive beneath the trees were bryophytes, namely, Hypnum jutlandicum, H. andoi,
H. resupinatum, Lophocolea bidentata, Pseudotaxiphyllum elegans, Polytrichum
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commune, Rhytidiadelphus loreus, Hylocomium splendens, Thuidium tamariscinum,
Plagiothecium undulatum, Sphagnum fallax, Campylopus flexuosus and Dicranella
heteromalla.
This area of planted woodland corresponds to Phase 1 code: A1.2.2 (see Map
2 below).
Map 2: Revised Phase 1 map showing the additional survey areas.
2.2 Option 2
This temporary construction site option lies in an area of acid grassland which
is slowly reverting to heath. As such, it corresponds to NVC U5 Nardus stricta-
Galium saxatile grassland ( Phase I code B 1.1 Unimproved acid grassland) with a
trend towards NVC: H8 Calluna vulgaris-Ulex gallii heath. The area is sheep-
grazed and generally free-draining. Species noted here include Nardus stricta, Juncus
squarrosus, Empetrum nigrum, Potentilla erecta, Vaccinium myrtillus, Galium
saxatile, Agrostis capillaris, Festuca ovina, Erica cinerea, Carex binervis, C.
panicea, Polygala serpyllifolia, Ulex gallii, Calluna vulgaris, Erica tetralix and
Trichophorum germanicum with the common bryophytes Pleurozium schreberi,
Racomitrium lanuginosum, R. fasciculare, Polytrichum juniperinum, Polytrichastrum
formosum, Hypnum jutlandicum and Sphagnum squarrosum. The lichen Cladonia
impexa is common throughout.
2.3 Option 3
This proposed temporary construction compound site is located between the
coniferous forestry block described above and a large slate waste tip (Phase 1 code I
2.2) (see Map 2 above). The habitat details have been amalgamated into the slate
waste tip marked on Map 2. However, this option lies within a small area of wetland
dominated by Soft Rush (Juncus effusus) which corresponds to NVC: M23b Juncus
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effusus/acutiflorus – Galium palustre rush pasture. This stand of rushes has few
other species associated with it, namely Holcus lanatus, Juncus bulbosus, J.
acutiflorus, Epilobium palustre, Rumex acetosa, Agrostis stolonifera, Potentilla
erecta, Galium saxatile, G. palustre, Cirsium palustre, Nardus stricta, Luzula
multiflora, Scutellaria minor, Cardamine pratensis, Ranunculus acris, Digitalis
purpurea, Dryopteris carthusiana, Urtica dioica, Stellaria alsine and the bryophytes
Polytrichum commune, Sphagnum fallax, S. palustre, Kindbergia praelonga,
Pleurozium schreberi, Hylocomium splendens, Rhytidiadelphus squarrosus,
Pseudoscleropodium purum , Calliergonella cuspidata and Thuidium tamariscinum.
Although this is the species-poor sub-community of the NVC: M23 rush
pasture, it is unusual in the amount of the plant Chrysosplenium oppositifolium
present. This often forms an extensive carpet at the base of the rushes and its
presence suggests that a spring lies beneath this stand of rushes. As such it has close
affinities with the NVC: M32 Philonoto-Saxifragetum stellaris spring, although
neither of the usual constants appeared to be present.
Much of this Juncus effusus dominated rush pasture is surrounded by acid
grassland which is contiguous with the adjoining tip. Additional species noted here
include Juncus squarrosus, Festuca ovina, Agrostis capillaris, Carex panicea and C.
binervis. Both Empetrum nigrum and Vaccinium myrtillus are found here in very
small quantities.
2.4 DISCUSSION
Of the three Options for temporary construction compounds, Option 1 is by far
the most suitable from an ecological perspective. This piece of coniferous plantation
has few species associated with it and the stand is likely to become further lodged
now the process has demonstrably started. Option 2 is the acid grassland which
clearly has the potential to revert to quite nice lowland heath. Option 3 is the least
suitable. It is a very wet site and it is likely there is much stored carbon lying beneath
the dense rushes. Welsh Government are currently putting a lot of emphasis on
preserving such carbon sinks and, quite apart from the difficulties associated with
placing a construction compound on such a wet site, such habitats should be
conserved as far as is possible. The presence of Chrysosplenium oppositifolium
indicates how wet this site is.
2.5 PROTECTED SPECIES
No signs of Protected Species were noted on or close to any of the three site
options. However, should Option 1 be selected as a temporary construction
compound, it is recommended that a breeding bird survey is carried out before it is
used. It is not unlikely some bird species might use the forestry for nesting.
3.0 TEMPORARY CONSTRUCTION COMPOUNDS: LOWER SITES
Two Brownfield sites have been suggested lower down the mountain both of
which lie close to QV6 (see Map 1).
3.1 Site 1
This site lies to the immediate south of QV6 and is a recently created site
levelled and covered in compacted crushed slate waste (see Photo 1). Much of the
site is surrounded by artificial bunds now planted with trees in tubes. This site was
5
not surveyed since very little vegetation had colonised the slate waste floor at the time
of the survey. The site is designated as Bare Ground (Phase 1 code J4, see Map 2).
Photo 1: The proposed temporary construction compound to the south of QV6.
3.2 Site 2
This is essentially similar to the site described above, being man-made. It lies
somewhat to the north-east of QV6 and is designated as Phase I code J4 in Map 2.
However, despite the fact that this area has recently been used for the storage of
materials and plant used in the construction of the new Glyn Rhonwy Business Park,
(it too is surfaced with compacted crushed slate waste), it has nevertheless developed
quite a varied flora of ruderal species. These include Buddleja davidii, Geranium
robertianum, Anagallis arvensis, Poa annua, Betula pubescens, Prunella vulgaris,
Erodium cicutarium, Epilobium montanum, E. brunnescens, Ranunculus repens,
Sagina procumbens, S. apetala, Veronica serpyllifolia, V. officinalis, Ulex europaeus,
Sonchus asper, Verbascum thapsus, Plantago major, P. lanceolata, Cerastium
fontanum, C. glomeratum, Senecio vulgaris, S. jacobaea, Sedum anglicum, Teucrium
scorodonia, Trifolium dubium, Centaurium erythraea, Solanum dulcamara, Cirsium
vulgare, Aira praecox, Pilosella officinarum, Saxifraga x urbium, Linaria purpurea,
Reseda luteola, Tripleurospermum inodorum and the bryophytes Racomitrium
canescens and R. fasciculare.
3.3.DISCUSSION
Being Brownfield sites, both these proposed temporary construction
compounds would have negligible ecological impacts on the colonising flora which is
of little interest.
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3.4 PROTECTED SPECIES
No signs of Protected Species were found on either site.
4.0 THE PIPELINE ROUTE BETWEEN QV6 AND LLYN PADARN
This follows the line shown to the far right hand side of Map 1 above and
goes through an area of secondary broadleaved woodland which has largely colonised
the slate tips associated with earlier quarrying. While there are the occasional semi
mature oaks (Quercus petraea) within this woodland, most of the tree species are
considerably younger. Species noted include Betula pubescens, Salix cinerea,
Fraxinus excelsior and the occasional invasive Rhododendron ponticum. Much of the
understorey is dominated by dense Bramble (Rubus fruticosus) suggesting this piece
of woodland is seldom grazed. Other species noted in the ground layer were Holcus
lanatus, H. mollis, Rosa canina, Geum urbanum, Circaea lutetiana, Viola riviniana,
Hedera helix, Dryopteris affinis, D. dilatata, Geranium robertianum, Carex remota
and the mosses Thuidium tamariscinum and Dicranum scoparium. However, much of
the ground layer is more typical of ruderal species colonising the ubiquitous slate
waste that covers the secondary woodland floor. Some species noted in this category
were Vicia sativa, Aira caryophyllea, Ranunculus repens, Senecio jacobaea,
Geranium molle, Sonchus asper, Potentilla reptans, Epilobium montanum, E.
brunnescens, Lotus pedunculatus, Veronica chamaedrys, Galium aparine, Filipendula
ulmaria, Stachys sylvatica, Calystegia sepium, Scrophularia nodosa, Fragaria vesca,
Cardamine flexuosus, Anthoxanthum odoratum, Crepis capillaris, Euphrasia sp.,
Aphanes australis, Glechoma hederacea, Erica cinerea and Juncus effusus. This
woodland conforms to the A 1.1.1 Phase 1 category (see Map 2).
After leaving the woodland, the pipeline will cross the A4086 and enter the
secondary woodland of the Padarn Country Park and thence to the pump house on the
shores of the Lake. Similar species were noted in the Country Park which is best also
described as secondary broadleaved woodland established on slate waste arising from
the quarrying activities on the slopes above.
4.1 DISCUSSION
It is not clear where the exact route through this secondary woodland the
pipeline will follow and it is, therefore, recommended that a much more detailed
botanical survey will be required in order to avoid untoward felling of trees. This will
only be possible if the route is marked out in detail by an engineer beforehand. There
are also some concerns as to how the pipeline will bypass a number of buildings on
the eastern side of the A4086 before it enters the Padarn Country Park. Also, to avoid
felling of trees within the Country Park itself, a more detailed pipeline route needs to
be precisely positioned and a detailed botanical (and Protected Species) survey
undertaken in order to ascertain the full impact of the proposed pipeline route.
4.2 PROTECTED SPECIES
As has already been mentioned, the exact route of the pipeline through the
woodland and down to the shores of Llyn Padarn needs to be finalised before
definitive and meaningful surveys can be conducted. There is some concern, for
example, as to how exactly the old Bomb Store will be negotiated since it appears to
be directly in line with the proposed pipeline route. It is known that bats use the
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Bomb Store for roosting and possibly as a breeding maternity roost. Full summer and
winter bat emergence surveys would be required.
5.0 PUMP HOUSE AND OUTFLOW BY LAKE
As has already been mentioned, the whole area of the Padarn Country Park,
where the pump house and outflow is proposed to be located, is made up of secondary
broadleaved woodland lying on slate waste. The woodland is essentially confined to
smallish groups of trees interspersed with rough tracks and parking places. As such,
there is little soil at the base of the trees and the flora is somewhat impoverished as a
result. Much of the woodland is also prone to periodic flooding from the rising levels
of the Lake.
The pump house will be located a few metres from the Lake shore within the
woodland itself. The woodland is made up principally of mature Betula pubescens
with developing saplings of Ilex aquifolium, Quercus petraea, Salix cinerea, Acer
pseudoplatanus and Fraxinus excelsior. Other species noted in the ground layer
include Rubus fruticosus, Solidago virgaurea, Polypodium vulgare, Hedera helix,
Holcus lanatus, Festuca ovina, Anthoxanthum odoratum, Geranium robertianum,
Chamerion angustifolium, Veronica officinalis, Circaea lutetiana, Ranunculus repens,
Juncus tenuis, Hypochoeris radicata, Rumex sanguineus, Mycelis muralis and the
bryophytes Thuidium tamariscinum, Rhytidiadelphus loreus, Calliergonella
cuspidata, Hypnum andoi, Isothecium myosuroides, Dicranum scoparium and Ulota
crispa. As with much of the slate tips in the whole of the Glyn Rhonwy quarry
complex, the invasive Buddleja davidii is found throughout the Country Park. The
only plant of interest, though only found in small quantity, is Melampyrum pratense, a
native of broadleaved woodland in North Wales.
The outflow by the Lake is typified by similar woody species, principally
Betula pubescens and Salix cinerea with saplings of Quercus petraea. A number of
forbs were also noted, namely Senecio jacobaea, Geum urbanum, Teucrium
scorodonia, Plantago lanceolata, Fragaria vesca, Prunella vulgaris, Sedum
anglicum, Sagina procumbens, Angelica sylvestris, the grasses Holcus lanatus and
Agrostis capillaris and the bryophytes Hypnum cupressiforme, Racomitrium affine, R.
fasciculare, Calliergonella cuspidata, Pseudoscleropodium purum and Climacium
dendroides in some abundance covering boulders on the shore itself.
5.1 DISCUSSION
There is little of ecological significance that is likely to be affected by the
proposed development within the Padarn Country Park itself.
5.2 PROTECTED SPECIES No signs of Protected Species were noted during the survey. The Country
Park is very busy during daylight hours throughout the year being used extensively by
groups launching canoes and boats. It is unlikely, therefore, that such regular
disturbance would favour the presence of Water Voles or nesting birds. Despite
careful search, there were no signs of Otter lie up sites in the vicinity of the outflow to
the Lake but it is quite likely this species uses the Lake for feeding during the night
when there is less disturbance. It is unlikely other surveys will be required of this
area.
