Planning Case Study 8
Quedgeley Trading Estate East, Haresfield, Gloucestershire
Heritage assets affected
Undesignated heritage assets with archaeological and historic interest
Type of application & broad category
Local planning authority
Authority: Stroud District Council
Archaeological information known about the site before the planning application was made, or before the development commenced, as appropriate
There were no known archaeological remains on the site, apart from a possible windmill mound recorded on early maps, and ridge and furrow earthworks identified from historic aerial photographs (levelled by the time that development was proposed). The general area is also thought to have been the location of a locally significant medieval pottery industry, and nearby RAF structures were also of heritage interest.
An EIA undertaken in relation to a proposed business park development included a desk-based assessment and subsequent field evaluation in the form of geophysical survey and trial trenching.
A geophysical (magnetometer) survey was undertaken over 14ha. The report interpreted the results as including a possible circular prehistoric enclosure in one corner of the site, with a further rectilinear enclosure nearby, also thought likely to be prehistoric. An area of strong anomalies was tentatively interpreted as evidence for medieval pottery kilns, and the ridge and furrow that had previously been mapped from aerial photographs was also recorded.
Subsequent evaluation trenching led to the circular enclosure being reinterpreted as a Bronze Age round barrow (possibly the feature wrongly labelled on early maps as a windmill mound; the barrow may have subsequently been reused as a windmill mound). The fills of the rectilinear enclosure ditches were, however, of medieval date. There was no evidence for pottery production on the site itself; the anomaly thought to have resulted from kiln waste turned out to be a large modern pit, probably associated with a WWII RAF station nearby.
The evaluation report stated that there was ‘poor correlation’ between identified archaeological features and geophysical anomalies. In particular, the geophysical survey had failed to predict an extensive medieval field system (unrelated to the later ridge and furrow), the ditches of which produced significant quantities of the local 11th – 13th century pottery.
A pre-commencement planning condition specifying a programme of archaeological investigation was attached to the planning permission for development, and a WSI has recently been approved.
This case demonstrates the importance of evaluation trenching to test the results of geophysical survey. The interpretation and presumed date of the features identified by geophysical survey were significantly altered following evaluation and extensive further features were discovered.
The need for trial trenching to confirm geophysical results is often questioned by consultants. This case illustrates that the assessments of significance of heritage assets required by the NPPF may be unreliable when only remote sensing data is provided.
References and links/bibliography
- Cotswold Archaeology 2015, Land at East Quedgeley: Heritage Assessment. Unpublished report, CA report 15794.
- Pre-Construct Archaeology 2016, Land at East Quedgeley, Gloucestershire, Archaeological Geophysical Survey. Unpublished report.
- Cotswold Archaeology 2016, Land at Quedgeley East, Gloucestershire, Archaeological evaluation. Unpublished report, CA report 16505.