Planning Case Study 69

An Archaeological Appraisal (WYG 2012) using HER information identified various archaeological remains within, but mainly around the scheme area, including the scheduled monument of Haltemprice medieval priory (NHLE no. 1019825) immediately to the north of the Carr Lane reservoir. The appraisal recommended a programme of archaeological evaluation, commencing with geophysical survey, followed by appropriate mitigation.

A formal desk-based assessment was not undertaken as part of the planning application.

The planning application was submitted in November 2012 and approved March 2013.

The archaeological adviser to the LPA had highlighted the potential impact of the scheme on the adjacent scheduled monument and the general archaeological potential of the scheme area, both in terms of known sites and also the potential for previously undiscovered archaeological remains to be present, recommending evaluation prior to the determination of the application.

A pre-commencement planning condition was attached to the planning permission to secure a programme of archaeological investigation, analysis, publication, and archiving, commencing with evaluation.

A geophysical survey on two of the four main areas to be affected by the scheme (WYAS 2013) suggested limited remains, comprising occasional ditches, field boundaries shown on the Ordnance Survey First Edition maps, ridge and furrow, field drains, and a single square anomaly at Carr Lane.

The monitoring of limited geotechnical works (Atkinson 2014; Jobling 2014) did not identify any further archaeological remains.

A mitigation strategy for four areas for lagoons (totalling 20 ha) and several hundred metres of interconnected drainage was proposed. The WSI for the strategy (Barton Howe Associates 2014a) synthesised information from the HER, previous archaeological investigations in the area, aerial photographic information and the results of the geophysical survey. Given the limited results, the WSI concluded that none of the investigation areas had high potential for archaeological remains.

The mitigation strategy envisaged a two-stage process in the field: during the first, referred to as ‘evaluation’ the archaeological areas would be stripped and mapped, with a representative selection of features sample excavated. Proposals for investigation would then be submitted for a second stage, comprising detailed excavation.

Fieldwork (March-Nov 2015): The stripping of the topsoil in areas to be investigated was undertaken as part of the general development groundworks, albeit that the plant was supervised by archaeologists. Sufficient staff were deployed to supervise stripping across several active locations, together with a small investigation team to characterise selected findings, in line with the low density of archaeological remains expected. However, concentrations of prehistoric, Roman, early medieval and later medieval archaeological remains were soon identified across many of those areas that were stripped to the surface of the natural geology. These not only exceeded the capacity of the investigation team, but were also in locations that were on the critical path for drainage infrastructure. The situation was not aided by soft ground and machine rutting, which meant that the stripping/spoil management methodology also had to be revised.

It soon became apparent that it would not be possible in either practical terms, or within the constraints of the project timetable, to strip, map and sample-excavate each archaeological area, submit an ‘evaluation’ report, and agree proposals for subsequent detailed excavation. Instead, it was agreed that detailed excavation would commence immediately, following the sampling strategies that had been set out in the WSI and Scope of Archaeological Works, and developed in the OA North Project Design (2015). As a result, large numbers of archaeologists were rapidly deployed to undertake the detailed excavation.