On Archaeology Ae
Total Page:16
File Type:pdf, Size:1020Kb
Ty Coch Hydro Scheme, Nantlle, Gwynedd. March 2014 on archaeology e a Archaeological Desk-Based Assessment Project Code: A0034.1 Report no. 0034 Ty Coch Hydro Scheme, Nantlle, Gwynedd. March 2014 Report no. 0034 v1.0 Archaeological Desk-Based Assessment Aeon Archaeology 17 Cecil Street Chester CH3 5DP on archaeology e a Project Code: A0034.1 Date: 25/03/2014 Client: Greenearth Hydro Ltd WriƩen by: Richard Cooke BA MA MIfA [email protected] Figures Figure 01: LocaƟon of proposed hydro scheme. Scale 1:3,500 at A4. Figure 02: LocaƟon of monument points from the Gwynedd HER, new monument points and Scheduled Ancient Monuments. Scale 1:10,000 at A4. Figure 03: LocaƟon of monument points from the NaƟonal Monuments Record and Listed Buildings. Scale 1:10,000 at A4. Figure 04: LocaƟon of Historic Landscape Character Areas (HLCAs). Scale 1:10,000 at A4. Figure 05: First ediƟon 25” County Series Ordnance Survey map of 1889. Figure 06: Second ediƟon 25” County Series Ordnance Survey map of 1900. Figure 07: Third ediƟon 25” County Series Ordnance Survey map of 1916. Figure 08: LocaƟon of archaeological sites idenƟfied during the site visit. Scale 1:3,500 at A4. Figure 09: LocaƟon and orientaƟon of photographs. Scale 1:3,500 at A4. Plates Plate01: View of proposed hydro intake weir, from the northeast. Plate 02: View of proposed hydro penstock route, from the south. Plate 03: View of proposed turbine house locaƟon, from the southeast. Scale 1.0m. Plate 04: Revetment wall (feature 1), from the north. Scale 1.0m. Plate 05: Trackway (feature 2), from the northeast. Scale 1.0m. Plate 06: Stone cairn (feature 3), from the northwest. Scale 1.0m. Plate 07: Revetment wall (feature 4), from the northwest. Scale 1.0m. Plate 08: Relict field wall (feature 5), from the south. Scale 1.0m. Plate 09: Clawdd wall (feature 6), from the northwest. Scale 1.0m. Plate 10: Bank and ditch (feature 7), from the northeast. Scale 1.0m. Plate 11: Field wall (feature 8), from the northwest. Scale 1.0m. Plate 12: Field boundary (feature 9), from the northwest. Scale 1.0m. Plate 13: Field wall (feature 10), from the southeast. Scale 1.0m. Plate 14: Possible long hut (feature 11), from the northeast. Scale 1.0m. Plate 15: Possible round hut (feature 12), from the southeast. Scale 1.0m. Plate 16: Possible long hut (feature 13), from the southwest. Scale 1.0m. Plate 17: Boulder field (feature 14), from the northwest. Plate 18: SecƟon of wall (feature 15), from the northeast. Scale 1.0m. Plate 19: Stony spread (feature 16), from the south. Plate 20: Ditch (feature 17), from the southwest. Scale 1.0m. Plate 21: Terrace (feature 18), from the southeast. Plate 22: Terrace (feature 19), from the northeast. Scale 1.0m. Plate 23: Terrace (feature 20), from the northeast. Scale 1.0m. 1.0 NON-TECHNICAL SUMMARY ........................................................................................1 2.0 INTRODUCTION, AIMS AND PROJECT DESIGN .........................................................2 3.0 METHODS AND TECHNIQUES .......................................................................................4 3.1 Archival research ..............................................................................................................4 3.2 Site walkover ....................................................................................................................4 3.3 Desk-based assessment report ...........................................................................................4 3.4 Project archive ..................................................................................................................4 4.0 ARCHAEOLOGICAL AND TOPOGRAPHICAL BACKGROUND ................................6 4.1 Topographic Description ..................................................................................................6 4.2 Statutory and non-statutory designations ..........................................................................6 4.2.1 Non-designated monument points from the Gwynedd Historic Environment Record (figure 2)..............................................................................................................................6 4.2.2 Scheduled Ancient Monuments (figure 2) .................................................................7 4.2.3 Listed Buildings (figure 3) .........................................................................................7 4.2.4 National Monuments Record (figure 3) .....................................................................7 4.2.5 Historic Landscape Character Areas (HLCAs) (figure 4) ..........................................8 4.2.6 Historic Parks and Gardens ........................................................................................8 4.2.7 Events .........................................................................................................................9 5.0 THE HISTORICAL CONTEXT ........................................................................................10 5.1 Prehistoric and Roman Period ........................................................................................10 5.2 Early Medieval, Medieval and Post-Medieval Periods ...................................................11 6.0 ASSESSMENT OF HISTORICAL ASSETS ....................................................................13 6.1 Definitions ......................................................................................................................13 7.0 SITE GAZETTEER – PHYSICAL IMPACTS ..................................................................16 8.0 IMPACT AND RECOMMENDATIONS ..........................................................................39 8.1 Direct physical impact ....................................................................................................39 8.2 Indirect physical and non-physical (visual) impact ........................................................39 8.3 Historic Landscapes ..................................................................................................39 8.4 Site Specific Recommendations .....................................................................................39 8.5 General recommendations ..............................................................................................40 9.0 SOURCES ..........................................................................................................................41 APPENDIX 1: SCHEDULED AND NON-SCHEDULED SITES WITHIN 1.0KM..............43 APPENDIX 2: DEFINITIONS OF FURTHER ASSESSMENT AND MITIGATORY MEASURES .............................................................................................................................51 aeon archaeology 1.0 NonTechnicalSummary 1.0 NON-TECHNICAL SUMMARY Aeon Archaeology was commissioned by Greenearth Hydro Ltd to undertake an archaeological desk-based assessment of a proposed new hydro-electric scheme with turbine house, buried penstock (pipeline), and electrical cable connection. The proposed scheme intake is to be located on the eastern bank of the Afon Ty Coch, an outfall stream of Llynnau Cwm Silyn and a tributary of the Afon Llyfni, approximately 1.4km southwest of the village of Nantlle, Gwynedd and within the Snowdonia National Park Authority (SNPA). The archaeological desk-based assessment identified twenty archaeological sites within the 40.0m wide assessment corridor centred on the pipe route. Of these it is expected that the proposed scheme will have a low adverse direct physical impact upon two cloddiau and a trackway considered to be of local importance; a revetment wall of unknown importance but suspected to be of prehistoric date and national importance; and a ditch of unknown age. Site specific recommendations have been made for a watching brief to be maintained while the revetment wall and ditch features are breached and for any revealed archaeological remains to be recorded. In addition the report identified a boulder field, stony spread, and three flat terraces which are considered to have an increased potential for preserved buried archaeological remains and recommendations have been made for a watching brief to be maintained during the excavation of the penstock trench in these areas. The report also identified two possible medieval long-huts, a possible prehistoric hut-circle, and a section of walling that lie within the assessment corridor but away from the proposed penstock route. These features will not be directly impacted upon but there is a possibility that associated buried remains continue into the development area. As such recommendations have been made for a watching brief in proximity to these sites. 1 1.0 NON-TECHNICAL SUMMARY | Aeon Archaeology aeon archaeology 2.0 Introduction,AimsandProjectDesign 2.0 INTRODUCTION, AIMS AND PROJECT DESIGN Aeon Archaeology was asked by Greenearth Hydro Ltd to carry out an archaeological desk- based assessment and field visit of a proposed hydro-electric scheme with turbine house, buried penstock (pipeline), and electrical cable connection. The proposed scheme intake is to be located on the eastern bank of the Afon Ty Coch, an outfall stream of Llynnau Cwm Silyn and a tributary of the Afon Llyfni, approximately 1.4km southwest of the village of Nantlle, Gwynedd and within the Snowdonia National Park Authority (SNPA). The proposed scheme will consist of an intake weir located at NGR SH 50850 51890 and a c.890.0m long buried penstock initially running southwest to northeast before turning and heading northwest