Glyn Rhonwy Pumped Storage Development Consent Order Appendix 6.1 ASIDOHL Glyn Rhonwy Environmental Statement Appendix 6.1 ASIDOHL for the Dinorwig Historic Landscape Introduction SPH is proposing to develop a Pumped Storage scheme in the disused slate quarries at Glyn Rhonwy, near Llanberis in Gwynedd (hereafter referred to as the ‘Development’). This document assesses the potential impact of this development upon the Dinorwig historic landscape. This is the second iteration of this ASIDOHL, the first having been included in the 2012 Environmental Statement (AECOM 2012). Consultation Consultation with the Gwynedd Archaeological Planning Service (GAPS) has established that the Development was of sufficient scale for Assessment of the Significance of the Impact of Development on Historic Landscapes (ASIDOHL) to be required. The scope of assessment was determined through consultation with GAPS. This consultation identified the need for assessment of the effects of the Development on Dinorwig historic landscape, in which it lies and where visual change will be most significant. Whilst the Development can theoretically be seen from the eastern fringe of the Ogwen Valley/Dyffryn Ogwen historic landscape, the extent of change to existing views is negligible. Ogwen Valley has therefore been scoped out of this assessment. Consultation determined that no historic landscape other than Dinorwig needed to be considered. The original version of the ASIDOHL was reviewed by GAPS subsequent to the publication of the 2012 Environmental Statement. The comments made by GAPS have been addressed within the current version of the ASIDOHL. Consultation undertaken on archaeological matters for the 2015 ES is detailed In Chapter 11, Section 11.4. Assessment Standards The assessment has been undertaken according to the ASIDOHL Version 2 methodology (CCW, Cadw and WAG 2007). Stage 1: Contextual Information Description of development The Development comprises pumped storage in the disused slate quarries at Glyn Rhonwy, near Llanberis in Gwynedd. A description of the development is provided in Chapter 4 Project Description. The principal components of the Development to be assessed are as follows. Permanent features: Upper dam on Chwarel Fawr (Q1) (maximum elevation up to 395m AOD) with reservoir, relief valve and access shaft with relief spillway at Q1 to Nant Y Betws Lower dam on Glyn Rhonwy (Q6) (maximum elevation up to 154m AOD) with reservoir, scour value and access shaft and spillway with inlet and outlet from Q6 to Llyn Padarn 4.5m underground penstock connecting Q1 to Q6 through a bifurcation chamber and the turbine hall Page 1 of 26 Glyn Rhonwy Environmental Statement Volume 3, Appendix 6.1 – ASIDOHL for Dinorwig Historic Landscape Turbine house (maximum elevation of 15m to apex) located on existing development platform adjacent to Q6 4.5m tailrace tunnel connecting Turbine House to Q6 Pumping station, above ground kiosk and pipe inlet / outlet at Llyn Padarn Access to Q1 via a minor road (known locally as Green Lane) from Waunfawr Access to Q6 from the A4086 and through existing industrial estate internal roads Spoil heaps to the south-west of Q1, to accommodate approximately 930,000m3 Temporary features during construction: Site offices Construction compound (upper) Construction compound (lower) Temporary access shaft and tunnel from Q6 to penstock Assessment context This ASIDOHL has been undertaken as an integral part of the Environmental Impact Assessment (EIA) for the Development. This ASIDOHL forms an appendix to the Environmental Statement (ES). Other chapters and appendices of the ES contain information which informs this assessment, principally the following: Chapter 4 includes a scheme description, and supporting information for this chapter is contained in Volume 4 Figures Chapter 6 presents the Landscape and Visual Impact assessment (LVIA). Supporting information, including photomontages, can be found in Volume 4 Figures Chapter 11 presents the assessment of impacts on Cultural Heritage, and also discusses the policies relevant to heritage Policy Context The planning policy background is discussed in Chapter 5 of the Environmental Statement. Key legislation and guidance relating to archaeology and cultural heritage comprises the following. National policy Ancient Monuments and Archaeological Areas Act 1979 Planning (Listed Buildings and Conservation Areas) Act 1990 National Policy Statement (Energy) EN-1, Section 5.8 Planning Policy Wales Edition 7 (July 2014) Welsh Office Circular 60/96: Planning and the Historic Environment: Archaeology Welsh Office Circular 61/96: Planning and the Historic Environment: Historic Buildings and Conservation Areas Welsh Office Circular 1/98: Planning and the historic environment: directions by the Secretary of State for Wales Page 2 of 26 Glyn Rhonwy Environmental Statement Volume 3, Appendix 6.1 – ASIDOHL for Dinorwig Historic Landscape Gwynedd Unitary Development Plan 2001-2016 Built and Historic Environment - Strategic Policy 3: relates to the protection of the area’s built and historic environment and design standards for new development which will maintain or improve their special character Policy B3 – Development Affecting the Setting of Listed Buildings: relates to proposals on sites affecting the setting of Listed Buildings, including the protection of important views to and from the building Policy B4 – Developments in or Affecting the Setting of Conservation Areas: relates to the preservation and enhancement of conservation areas and their setting, including the protection of important views across, into or out of the conservation area Policy B7 – Sites of Archaeological Importance: relates to the protection of archaeological remains, whether designated or not, and includes the criteria under which development affecting remains would be permitted. This includes the requirement for archaeological assessment and/or evaluation, and for designs which allow preservation in situ of nationally important remains Policy B12 – Protecting Historic Landscapes, Parks and Gardens: relates to proposals which may cause significant harm to the character, appearance or setting of registered sites Policy C6 – Glyn Rhonwy Redevelopment Site: proposals must not, inter alia, adversely affect the outstanding visual and natural environment that it is set within. Any new buildings or associated development will have to integrate effectively with the topography, character and setting of the site. Eryri Local Development Plan 2007 – 2022 Strategic Policy Ff: Historic Environment – Development will not be permitted that will adversely affect Heritage Assets, or their settings and significant views. This includes Conservation Areas, Scheduled Monuments, Historic landscapes, parks and gardens and Listed Buildings. Confidence levels The Development is fully described and illustrated by the ES. The physical form and appearance of the development is fully understood. Photographs and photomontages have been prepared which illustrate the appearance and scale of the scheme from a number of locations, including from positions within the Dinorwig historic landscape. The Dinorwig historic landscape is outlined in the Register of Landscapes of Outstanding Historic Interest in Wales (Cadw, CCW & ICOMOS UK 1998). It has been subject to a detailed characterisation exercise undertaken by Gwynedd Archaeological Trust (GAT). The Zone of Theoretical Visibility (ZTV) for the development has been established by the LVIA (Chapter 6; Figure 6.3) and has been refined in the field by both the landscape architect and the archaeologist undertaking the ASIDOHL. The field visits enabled the true situation on the ground to be appreciated, particularly in terms of the role of tree cover and other vertical landscape elements which dictate the availability of long-distance views. Confidence levels for this ASIDOHL are therefore high in most respects. However, effects on access and amenity (i.e. indirect physical impacts), which may be either positive or negative, cannot be quantified. Although the project has aspirations for enhanced public access and amenity within Page 3 of 26 Glyn Rhonwy Environmental Statement Volume 3, Appendix 6.1 – ASIDOHL for Dinorwig Historic Landscape the Order Limits, no measures to achieve this have been defined. An element of uncertainty therefore remains within the Stage 3 calculations. Qualifications and experience This ASIDOHL has been undertaken by Andrew Pearson MA PhD MIfA FSA. Dr Pearson has worked as an archaeologist in Wales for 15 years and during this time has undertaken a significant number of ASIDOHL studies. He has also carried out critical review of ASIDOHL and other landscape studies on behalf of CCW. Process description This assessment has been undertaken to ASIDOHL Version 2 standards. All five stages have been undertaken. Historic landscapes under consideration The proposed project lies within the Dinorwig historic landscape, as described in the Register of Landscapes of Outstanding Historic Interest in Wales (Cadw, CCW and ICOMOS UK 1998). This document is complemented by the characterization exercise for Ardal Arfon. This area incorporates the historic landscapes of Dinorwig, Ogwen Valley and some of North Arllechwedd (the rest of the latter being included in a separate study). The characterization exercise is available at: http://www.heneb.co.uk/arfonintro/arfonlandscapemap.html Identification of key historic landscape characteristics and determination of study