Thames Water Mains Replacement Bourton-On-The-Water

THAMES WATER MAINS REPLACEMENT BOURTON-ON-THE-WATER

GLOUCESTERSHIRE

ARCHAEOLOGICAL WATCHING BRIEF

For

OPTIMISE

on behalf of

THAMES WATER UTILITIES

CA PROJECT: 3198 CA REPORT: 10173

OCTOBER 2010

THAMES WATER MAINS REPLACEMENT BOURTON-ON-THE-WATER GLOUCESTERSHIRE

ARCHAEOLOGICAL WATCHING BRIEF

CA PROJECT: 3198 CA REPORT: 10173

prepared by Jonathan Hart, Publications Officer and Jamie Wright, Project Officer

date 24 October 2010

checked by Cliff Bateman, Project Manager

date 25 0ctober 2010

approved by Simon Cox, Head of Fieldwork

signed

date 26 October 2010

issue 01

This report is confidential to the client. Cotswold Archaeology accepts no responsibility or liability to any third party to whom this report, or any part of it, is made known. Any such party relies upon this report entirely at their own risk. No part of this report may be reproduced by any means without permission.

© Cotswold Archaeology Building 11, Kemble Enterprise Park, Kemble, Cirencester, Gloucestershire, GL7 6BQ Tel. 01285 771022 Fax. 01285 771033 E-mail: [email protected] © Cotswold Archaeology Thames Water Mains Replacement, Bourton-on-the-Water, Gloucestershire: Archaeological Watching Brief

CONTENTS

SUMMARY...... 2

1. INTRODUCTION ...... 3

2. RESULTS (FIGS 2–5)...... 4

3. DISCUSSION...... 5

4. CA PROJECT TEAM ...... 6

5. REFERENCES ...... 6

APPENDIX A: CONTEXT DESCRIPTIONS ...... 7 APPENDIX B: THE FINDS ...... 8 APPENDIX C: OASIS REPORT FORM...... 8

LIST OF ILLUSTRATIONS

Fig. 1 Site location plan (1:25,000) Fig. 2 The site, showing location of groundworks (1:1250) Fig. 3 Photograph, north facing section of pipe trench Fig. 4 Photograph, trenching towards probable palaeochannel 016 Fig. 5 Photograph, bank 012: looking south

1 © Cotswold Archaeology Thames Water Mains Replacement, Bourton-on-the-Water, Gloucestershire: Archaeological Watching Brief

SUMMARY

Project Name: Thames Water Mains Replacement Location: Bourton-on-the-Water, Gloucestershire NGR: SP 1761 2164 to SP 1802 2153 Type: Watching Brief Date: 9 August to 13 September 2010 Location of Archive: To be deposited with Corinium Museum Site Code: TBW 10

An archaeological watching brief was undertaken by Cotswold Archaeology during groundworks along the Thames Water Mains Replacement, Bourton-on-the-Water, Gloucestershire.

Two probable Holocene palaeochannels were identified cutting into the gravel terrace of the River Windrush. Deposits of Holocene alluvium were also present and were sealed by a low gravel bank which was visible as an earthwork either side of the pipeline. Although it remained undated, the bank was clearly cut by the existing field boundaries.

2 © Cotswold Archaeology Thames Water Mains Replacement, Bourton-on-the-Water, Gloucestershire: Archaeological Watching Brief

1. INTRODUCTION

1.1 In August and September 2010 Cotswold Archaeology (CA) carried out an archaeological watching brief for Optimise, on behalf of Thames Water Utilities, along the Thames Water Mains Replacement, Salmonsbury Fields, Bourton-on-the- Water, Gloucestershire (NGR: SP 1761 2164 to SP 1802 2153; Fig. 1). The work comprised Permitted Development but was governed by Thames Water’s responsibilities under the Code of Practice on Conservation, Access and Recreation (LHA 2010). The objective of the watching brief was to record all archaeological remains exposed during the development.

1.2 The watching brief was carried out in accordance with a request for archaeological recording by Charles Parry, Senior Archaeological Officer, Gloucestershire County Council (GCC), and with a Brief for archaeological recording issued by Lang Hall Archaeology (LHA) for Optimise, on behalf of Thames Water Utilities (LHA 2010). The methodology of the work was detailed in a subsequent Written Scheme of Investigation (WSI) produced by CA (2010) and approved by Optimise acting on the advice of LHA. The fieldwork also followed the Standard and Guidance for an Archaeological Watching Brief issued by the Institute for Archaeologists (2008), the Statement of Standards and Practices Appropriate for Archaeological Fieldwork in Gloucestershire issued by Gloucestershire County Council Archaeology Section (1995), the Management of Archaeological Projects (English Heritage 1991) and the Management of Research Projects in the Historic Environment (MORPHE) (English Heritage 2006).

The site 1.3 The pipeline route measures c. 400m in length and traverses meadows to the east of Bourton-on-the-Water within the floodplain of the Rivers Dikler and Eye, both tributaries of the River Windrush (Figs 1 and 2). It lies at approximately 120m AOD and is generally level ground. The majority of the site forms part of the Salmonsbury Meadows, a Site of Special Scientific Interest designated because of its species-rich unimproved meadows (GWT 2010).

1.4 The underlying solid geology of the area is mapped as Mudstone of the Jurassic Charmouth Mudstone Formation (BGS 2010). Quaternary deposits of the Sherborne Member (limestone gravel forming a terrace of the River Windrush) are mapped to

3 © Cotswold Archaeology Thames Water Mains Replacement, Bourton-on-the-Water, Gloucestershire: Archaeological Watching Brief

the east of the River Dikler and west of the River Eye, while Holocene Alluvium deposits (Clay, Silt, Sand and Gravel) are mapped between the rivers. Blue-grey clay overlain by calcareous gravel was exposed during the watching brief.

Archaeological background 1.5 The Scheduled Monument of Salmonsbury Camp, an Iron Age hillfort with Neolithic origins, is located 800m to the south-west of the site (Lang 2008). A geophysical survey of the pipeline route undertaken by Archaeological Surveys Ltd indicated the presence of features of unknown provenance, although the existing pipe had caused considerable magnetic disturbance to the geophysical plot (AS 2010).

Methodology 1.6 The fieldwork followed the methodology set out within the WSI (CA 2010). An archaeologist was present during intrusive groundworks comprising deturfing throughout the 13m wide fenced corridor and the subsequent excavation of a 0.6m– 1m wide pipe trench as well as launch and reception pits for boring under the River Eye (Fig. 2).

1.7 Where archaeological deposits were encountered written, graphic and photographic records were compiled in accordance with CA Technical Manual 1: Fieldwork Recording Manual (2007).

1.8 The archive from the watching brief is currently held by CA at their offices in Kemble and will be deposited with Corinium Museum, Cirencester. A summary of information from this project, set out within Appendix C, will be entered onto the OASIS online database of archaeological projects in Britain.

2. RESULTS (FIGS 2–5)

2.1 The earliest encountered deposit was the geological substrate, comprising compact blue-grey clay 020/206, exposed at the bases of the pipe trench and the launch pit (Fig. 3).. It was overlain by several layers of white calcareous gravel with occasional bands of pale grey clay (layers 003, 017–019, 204 and 205), together measuring up to 0.4m thickness. The uppermost of these deposits had been cut by undated tree- throw pit 004 and by two probable palaeochannels, each approximately 50m–65m wide. Unfortunately, the extremely wet ground conditions prevented these deposits

4 © Cotswold Archaeology Thames Water Mains Replacement, Bourton-on-the-Water, Gloucestershire: Archaeological Watching Brief

from being recorded in section, so the morphology and depths of the probable paleochannels remained undetermined (Fig. 4). Neither the tree-throw pit nor the possible palaeochannels were recorded during the preceding geophysical survey.

2.2 The tree-throw pit and probable palaeochannels were sealed by several alluvial clay deposits (006, 009, 014, 015 and 203), which together were up to 0.4m thick. Of these, layer 009 contained a 0.05m thick deposit of tree bark fragments, 011.

2.3 Gravel bank 012 was built onto alluvial clay layer 009 (Fig. 5). This bank was 1.3m wide and 0.17m high and was visible as an earthwork within the fields either side of the pipeline, where it was clearly cut by the existing field boundaries. The bank was not recorded during the geophysical survey.

2.4 The foregoing deposits were sealed by subsoil 010/202 which was itself covered by topsoil (001, 002, 013 and 201). A layer of fragmented tree bark, 008, was present within the topsoil. The latest encountered deposits were the cut and fills of the existing water mains (cuts 207, 209 and 211; fills 208, 210 and 212).

The finds 2.5 The recovered finds assemblage comprises unstratified material collected during deturfing. This material includes Roman pottery, comprising single sherds of Central Gaulish Samian ware, Central Gaulish black-slipped ware, and a sandy greyware. The remaining material is modern and includes an iron nail and one sherd of refined whiteware with transfer print-decoration. As the material is unstratified, it will be discarded.

3. DISCUSSION

3.1 None of the discrete anomalies recorded during the geophysical survey were identified during the watching brief. The blue-grey clay exposed at the base of the pipe trench and launch pit is probably part of the Jurassic Charmouth Mudstone Formation (BGS 2010) with the overlying gravels forming part of the Quaternary Sherborne Member gravel terrace of the River Windrush (ibid.). The two probable paleochannels and the overlying alluvial clays probably relate to the Holocene Alluvium deposits mapped between the Rivers Dikler and Eye (ibid.).

5 © Cotswold Archaeology Thames Water Mains Replacement, Bourton-on-the-Water, Gloucestershire: Archaeological Watching Brief

3.2 Gravel bank 012 overlying the alluvial clay remained undated but formed part of an earthwork extending beyond the pipe corridor where it was cut by the existing field boundaries. The bank is visible on recent satellite images extending on a very straight alignment for over 200m. Its function and date remain undetermined, although the possibility that it was part of a former flood defence for the River Eye, or was associated with former water meadows, should not be overlooked.

4. CA PROJECT TEAM

Fieldwork was undertaken by Jonathan Hart and Jamie Wright, who co-authored this report. The illustrations were prepared by Lorna Gray. The archive has been compiled by Jonathan Hart and prepared for deposition by James Johnson. The project was managed for CA by Cliff Bateman.

5. REFERENCES

AS (Archaeological Survey) 2010 Salmonsbury Meadow, Water Main Replacement Work, Bourton-on-the-Water, Gloucestershire. Magnetomter Survey Report. Typescript report 328

BGS (British Geological Survey) http://www.bgs.ac.uk/geology viewer_google/googleviewer.html accessed 25 August 2010

CA (Cotswold Archaeology) 2010 Thames Water Mains Replacement, Bourton on the Water, Gloucestershire: Written Scheme of Investigation for an Archaeological Watching Brief

Lang, A. 2008 ‘Excavations at Bourton Primary School and the Cotswold School, Bourton- on-the-Water’, Glevensis 41, 5–11

LHA (Lang Hall Archaeology) 2010 A brief for monitoring of water main replacement in Salmonsbury Fields, Bourton-on-the-Water, Gloucestershire

GWT (Gloucestershire Wildlife Trust) http://www.gloucestershirewildlifetrust.co.uk/Gwt/Gwt.Nsf/WEBARTICLE?OpenForm &id=7C5F41BEB0A560B08025742F0039F5F8 accessed 27 October 2010

6 © Cotswold Archaeology Thames Water Mains Replacement, Bourton-on-the-Water, Gloucestershire: Archaeological Watching Brief

APPENDIX A: CONTEXT DESCRIPTIONS

No. Type Description Length Width Depth Spot- (m) (m) (m) date 001 Layer Turf 0.1 002 Layer Topsoil 0.1 003 Layer Natural: calcareous sand and gravel 0.2 004 Cut Tree-throw pit 3.8 0.4 - 005 Layer Grey clay fill of 004 3.8 0.4 - 006 Layer Alluvium : pale grey clay 0.07 007 Layer Friable silt layer sealed by 006 - 008 Layer Intermittent spread of possible tree bark/reeds within 0.05 002 009 Layer Alluvium: grey clay 0.09 010 Layer Subsoil below layer 002 0.3 011 Layer Layer of tree bark within alluvium 009 0.05 012 Layer Field boundary: bank of gravel overlying alluvium 009 >13 1.3 0.17 013 Layer Topsoil between Rivers Dikler and Eye: grey loam 0.12 014 Layer Natural between Rivers Dikler and Eye: grey clay 0.2 015 Layer Natural seen in launch pit: grey clay 0.3 016 Layer Natural seen in launch pit: layer below layer 015 0.03 017 Layer Natural seen in launch pit: pale grey gravel below - layer 016 018 Layer Natural seen in launch pit: grey gravel below layer 0.14 017 019 Layer Natural seen in launch pit: yellow-brown gravel below 0.3 layer 018 020 Layer Natural seen in launch pit: compact blue-grey clay - below layer 019 201 Layer Topsoil 0.2 202 Layer Subsoil: mid orange-brown silty clay 0.1 203 Layer Alluvium below 201: green-grey clay 0.4 204 Layer Natural: white calcareous limestone gravel below 203 0.4 205 Layer Natural: grey silty sand with calcareous limestone >1.0 gravel lenses below 204. Not excavated to full depth 206 Layer Natural: compact blue-grey clay below 204 >0.4 207 Cut Cut for existing pipe trench 5m c. 1.6m 208 Fill Existing pipe trench 207: fill and pipe 5m c. 1.6m 209 Cut Cut for existing pipe trench 3m c. 1.6m 210 Fill Existing pipe trench 209: fill and pipe 3m c. 1.6m 211 Cut Cut for existing pipe trench 1m c. 1.6m 212 Fill Existing pipe trench 211: fill and pipe 1m c. 1.6m

7 © Cotswold Archaeology Thames Water Mains Replacement, Bourton-on-the-Water, Gloucestershire: Archaeological Watching Brief

APPENDIX B: THE FINDS

Table 1: finds quantification Context Description Ct. Wt. (g) Date u/s Roman pottery: CG Samian ware; CG black slipped ware, 3 16 - greyware 1 2 Modern pottery: refined whiteware 1 36 Modern nail

APPENDIX C: OASIS REPORT FORM

PROJECT DETAILS Project Name Thames Water Mains replacement, Bourton-on-the- Water, Gloucestershire: Archaeological Watching Brief Short description An archaeological watching brief was undertaken by Cotswold Archaeology during groundworks along the Thames Water Mains Replacement, Bourton-on- the-Water, Gloucestershire. Two probable Holocene palaeochannels were identified cutting into the gravel terrace of the River Windrush. Deposits of Holocene alluvium were also present and were sealed by a low gravel bank which was visible as an earthwork either side of the pipeline. Although it remained undated, the bank was clearly cut by the existing field boundaries and is likely therefore to be of some antiquity, perhaps being medieval or earlier in date. Project dates 9 August–13 September 2010 Project type Archaeological Watching Brief Previous work None Future work Unknown PROJECT LOCATION Site Location Thames Water Mains replacement, Bourton-on-the- Water, Gloucestershire Study area n/a Site co-ordinates SP 1761 2164 to SP 1802 2153 PROJECT CREATORS Name of organisation Cotswold Archaeology Project Brief originator Lang Hall Archaeology Project Design (WSI) originator Cotswold Archaeology Project Manager Cliff Bateman Project Supervisor Jonathan Hart and Jamie Wright PROJECT ARCHIVES Intended final location of Content archive Physical n/a n/a Paper Corinium Museum Context records, drawings Digital Corinium Museum reports BIBLIOGRAPHY CA (Cotswold Archaeology) 2010 Thames Water Mains replacement, Bourton-on-the-Water, Gloucestershire: Archaeological Watching Brief CA typescript report No. 10173

8 Reproduced from the 1998 Ordnance Survey Explorer map with the permission of Ordnance Survey on behalf of The Controller of Her Majesty's Stationery Office N c Crown copyright Cotswold Archaeological Trust 100002109

site

0 2.5km

COTSWOLD ARCHAEOLOGY

PROJECT TITLE Thames Water mains replacement Bourton-on-the-water, Gloucestershire FIGURE TITLE Gloucestershire Site location plan

DRAWN BYSCALE PROJECT NO. FIGURE NO. LG 1:25,000@A4 3198 1

alluvial clays 203

gravels 205

gravels 204 natural clays 206

COTSWOLD ARCHAEOLOGY 3 North facing section of pipe trench PROJECT TITLE Thames Water mains replacement Bourton-on-the-water, Gloucestershire FIGURE TITLE Photograph

DRAWN BYSCALE PROJECT NO. FIGURE NO. LG n/a 3198 3 4

bank 012

COTSWOLD ARCHAEOLOGY 4 Trenching towards probable palaeochannel 016 PROJECT TITLE Thames Water mains replacement Bourton-on-the-water, Gloucestershire 5 Bank 012, looking south FIGURE TITLE Photograph

DRAWN BYSCALE PROJECT NO. FIGURE NO. LG n/a 3198 4 & 5