«Prepared by Dyfed Archaeological Trust For: Cambrian Mines Trust DYFED ARCHAEOLOGICAL TRUST RHIF YR ADRODDIAD / REPORT NO. 2013/77 RHIF Y DIGWYLLIAD ...»
The steeper hill slopes and drier hilltops often support areas of dry heathland. These are particularly extensive in Cwm Ystwyth and to the east of the Elan valley reservoirs, covering around 5% of the site in total.
This heathland is generally dominated by heather and bilberry, with crowberry, cowberry and lichens all prominent in places. Grasses, such as sheep’s fescue, mat grass and wavy hair-grass, can be frequent and there is generally a well-developed moss layer. Sunny south-facing slopes at lower altitudes support heathland that is more open in character and is dominated by mixtures of heather and bell heather, with lichens, or by dense patches of western gorse. This vegetation is often associated with rock screes. The locally rare lesser twayblade can be found beneath the tall heather canopy on the hilltops to the north of Cwm Ystwyth.
There are several old metal mine sites within Elenydd. The main mining areas were in Cwmystwyth and at Nant Methan, Nant y Car and Rhiwnant valley in the east. All of these areas contain outcrops of metal rich rocks and large areas of partially vegetated mine spoil, extending to over 40 ha in total. Typically, these areas support a sparse sward of sheep’s fescue, mosses, including the rare lead moss, and a rich variety of specialised lichens, including many rare and scarce species. Rock outcrops at Cwmystwyth mine support several thriving populations of the scarce fern
forked spleenwort. Old mine shafts also provide roosting sites for several types of bat.
Cwmystwyth mine is of national importance for the study of mineralization in the Central Wales Orefield. The spoil tips at the mine contain abundant ore material, including galena, chalcopyrite and sphalerite, which enable the recognition of two main phases of mineralization. Additional interest is provided by the structural relationships and mineralogical variations displayed by the three main mineral veins, namely the Comet, Kingside and Mitchell’s lodes. These veins are exposed both at surface and in the underground workings and indicate at least two separate phases of vein emplacement.
The old mine tips and buildings remain generally undisturbed and the shafts and underground workings are left open to allow access for scientific study and bats but fenced off to maintain public safety and deter unauthorised access.
The landforms in Cwmystwyth known as Cwm Ddu and Cwm Tinwen are unique in upland Wales. Although these landforms resemble cirques that have been generated through glacial erosion, several studies have revealed that, whilst differing somewhat in overall structure, essentially they were formed by frost-shattered debris sliding down slope on the surface of perennial snow patches. Evidence collected from these landforms suggests that much of mid-Wales was ice-free during the last Ice Age. These areas are preserved as open landscape that is largely free of trees and scrub and man-made features.
7.2.5 For the SSSI the following aspects are directly relevant to the Cwmystwyth
Blanket bogs (on the upland area) Dry heathlands Calaminarian grasslands (metal tolerant / lichen rich grasses) Floating water plantain (in reservoirs on upland areas) Rare lead moss Lichens Geological formations Bats Vascular plant assemblage Forked spleenwort Asplenium septentrionale Breeding bird assemblage of upland moorland 7.3 Mwyngloddfa Cwmystwyth SSSI 7.3.1 The Mwyngloddfa Cwmystwyth SSSI covers an area of 0.14 square kilometres (CCW undated(c)). The SSSI lies within the wider Elenydd SAC but is not included within the Elenydd–Mallaen SPA. The SSSI lies entirely within the area of land owned by the CMT (Figure 6).
7.3.2 The SSSI citation includes both geological and biological features (Appendix 3). The mineralogy of the site includes the mineral lodes running through the area and their formation.
7.3.3 Within the Core Management Plan for the Elenydd SAC document, the Mwyngloddfa Cwmystwyth SSSI conservation objectives are described as follows (CCW 2008, revision 2013; Annex 1).
The numerous abandoned mine workings, rock outcrops and spoil tips at Mwyngloddfa Cwmystwyth are of national importance because they provide important information relating to the development of mineralization in the Central Wales Orefield. These rock outcrops, both at the surface and in the underground workings, and mineralized material within the spoil tips clearly show that the lead-, zinc- and copper-bearing veins were formed during two main phases. A long-term vision for this site will be focussed on maintaining access to the underground workings, preserving current levels of rock exposure at the surface, and maintaining the spoil tips in their present state. This will ensure that Mwyngloddfa Cwmystwyth will continue to provide one of the best localities for the study of mineralization in the Central Wales Orefield.
The extent of the mine spoil tips at Mwyngloddfa Cwmystwyth are not decreasing in height or area except as a result of the natural process of weathering and erosion. All of the rare lichen species recorded at this site, that are characteristic of soils or rocks with a high metal content, are present with their populations either stable or increasing. The open sward of lichen-rich grassland includes characteristic grass species such as common bent, sheep’s fescue, silvery and early hair-grass. Yorkshire fog is only occasional within the sward and perennial rye-grass is absent.
Access for hibernating bats in the system of underground workings is maintained. All four species previously recorded from the site, namely Daubenton’s, Natterer’s, Brown longeared and Whiskered bats are present during the winter months.
7.3.4 For this SSSI the following is directly relevant to the Cwmystwyth mines
Calaminarian grasslands Rare lead moss Lichens Geological formations Bats 7.4 Legal Protection of a SSSI area 7.4.1 The ‘Conservation of Habitats and Species Regulations 2010’ is again applicable to the SSSI area. For the Mwyngloddfa Cwmystwyth SSSI bats are specifically mentioned in the citation, which are all protected species.
7.4.2 As noted above for both the SAC and SPA areas, a list of operations that may damage the features of interest is given for each of the SSSIs. Before any of the operations on the list (see below) are undertaken NRW must be consulted and consents applied for. Where consents are granted they are usually accompanied by conditions which need to be adhered to ensure the proposed works do not impact on the integrity of the SSSI.
7.4.3 Where planning permission is needed for works within a SSSI, the local authority will seek the advice of NRW in advance of any determination of an application. Appropriate assessments may be needed to demonstrate that the proposed works will not impact upon the integrity of the SSSI.
7.4.4 Any planning permission granted for activities within a SSSI (once consents have been obtained) will also have environmental planning conditions placed upon it.
7.4.5 The list of operations that may damage features are almost identical for both the Elenydd and Mwyngloddfa SSSI sites. These are given below, with the types of damaging operations described for both SSSI sites.
7.4.6 The list of operations that may damage features are almost identical for both the Elenydd and Mwyngloddfa SSSI sites, with a few changes in wording and an additional one for Elenydd SSSI (13c). The potentially damaging operations are laid out in the tables below for both SSSI sites, taken from the documentation available on-line from the CCW website for the two SSSI sites (CCW 1992 – Elenydd & CCW 2000 – Mwyngloddfa Cwmystwyth).
Ref Elenydd SSSI – Type of operation No
1. Cultivation, including ploughing, rotovating, harrowing and re-seeding.
2. Any alterations in the present pattern or frequency of grazing by farm stock.
3. Introduction of stock feeding. Changes in stock feeding practice.
4. Any alterations in the present pattern or frequency of mowing or cutting vegetation.
5. Application of manure, fertilisers and lime.
6. Application of pesticides including herbicides (weedkillers).
7. Dumping, spreading or discharging of any materials.
8. Burning of vegetation, including muirburn (heather burning).
9. The deliberate introduction of any wild or domestic animal, plant or seed.
10. Killing or removal of any wild animal, excluding pests.
11. Destruction, removal or pruning of any plant or plant remains, including tree, shrub, herb, hedge, dead or decaying wood, moss, lichen, fungus, leaf-mould or turf.
12. Tree planting including afforestation. Changes in woodland management, including clear and selective felling, thinning, coppicing, modification of the stand or underwood and changes in species composition.
13a. Modification of field drainage including moor-gripping and the use of mole, tile, tunnel or other artificial drains.
13b. Modification to rivers, streams, ditches or drains, including their banks and beds, as by re-alignment, regrading, dredging or cleaning.
13c. Management of aquatic and bank vegetation.
14. Changes in the present utilisation of water including storage, the raising of water levels, irrigation and abstraction from existing water bodies and through boreholes.
15. Infilling of ditches, drains, pools or marshes.
16a. Introduction of, or changes in freshwater fishery management, including use of fish cages.
20. Extraction of minerals including peat, shingle, sand and gravel, topsoil, and subsoil.
21. Construction, removal or destruction of roads, tracks, walls, fences, hardstands, banks, ditches or other earthworks.
22. Storage of materials on or against landforms or rock outcrops, or on bog surfaces
23. Erection of permanent or temporary structures or the undertaking of engineering works, including the laying, maintenance or removal of pipelines and cables.
24. Modification of landforms, rock outcrops or bog, clearance of boulders, large stones, loose rock or scree and battering, buttressing or grading rock faces and infilling of quarries.
26. Use of vehicles likely to damage bog and moorland vegetation or bog and landform surfaces.
27. Recreational or other activities (such as motor-cycling) within the control of the owner or occupier likely to damage bog and moorland flora and fauna, or bog and landform surfaces.
28. Introduction of/change in game and waterfowl management. Introduction of/change in hunting practice.
Ref Mwyngloddfa Cwmystwyth SSSI – Type of operation No
1. Cultivation, including ploughing, rotovating, harrowing and re-seeding
2. Grazing and alterations to the grazing regime (including type of stock, intensity or seasonal pattern of grazing).
3. Stock feeding, the introduction of stock feeding and alterations to stock feeding practice.
4. Mowing or cutting vegetation, the introduction of mowing or cutting and alterations to the mowing or cutting regime.
5. Application of manure, slurry, silage liquor, fertilisers and lime.
6. Application of pesticides, including terrestrial and aquatic herbicides, (weedkillers)
7. Dumping, spreading or discharging of any materials.
8. Burning and alterations to the pattern or frequency of burnings.
9. Release into the site of any wild, feral, captive-bred or domestic animal*, plant, seed or micro-organism and any genetically modified organism.
10. Killing, injuring, taking or removal of any wild animal*, or the eggs/nests of any wild animal or the disturbing, taking, damaging or destroying of any wild animal in its place of shelter including pest control.
11. Destruction, displacement, removal or cutting of any plant or plant remains including tree, shrub, herb, dead or decaying wood, moss, lichen, fungus, leaf mould, turf or peat
12. Tree planting, including afforestation.
13a Drainage including the use of mole, tile, tunnel or other artificial drains.
13b Modification to the structure of water courses including rivers, streams, springs, ditches, drains, including their banks and beds, as by re-alignment, regrading, damming or dredging.
14. Alterations to water levels and tables and water utilisation including irrigation, storage and abstraction from existing water bodies and through boreholes. Also the modification of current drainage regime (eg through the installation of new pumps).
15. Infilling or digging of ditches, drains, ponds, pools, marshes, quarries or pits.
16a Freshwater fishery production and/or management, including sporting fishing and angling, the introduction of freshwater fishery production and/or management and alterations to freshwater fishery production and/or management.
20. Extraction of minerals including peat, shingle, hard rock, sand and gravel, topsoil, subsoil, spoil and mine waste dumps.
21. Destruction, construction, removal, re-routing, or regrading of roads, tracks, walls, fences, hardstands, banks, ditches or other earthworks, including soil and rock exposures.
22. Storage of materials on or against rock exposures and spoil tips.
23. Erection of permanent or temporary structures or the undertaking of engineering works, including drilling or the laying, maintenance or removal of pipelines and cables, above or below ground.
24. Modification of natural or man-made features and clearance of boulders, large stones, loose rock or scree and the battering, buttressing or grading of geological exposures and cuttings (rock and soil).
26. Use of vehicles.
27. Recreational activities.
28. Hunting practices and introduction of, and alterations to, hunting practice.
Notes (from CCW website – applicable to both lists):