Event/Activity EPM179 - Archaeological Watching Brief for the Flood Alleviation Scheme Copnor

An archaeological watching brief was carried out by Archaeology South-East during groundworks related to the Portsmouth Flood Alleviation Scheme in 2013. The works were undertaken at Copnor Road, Quartremaine Road, Great Salterns Lake, Great Salterns Golf Course and Tangier Road. The alignment of new pipes was largely located within the roads, but trenches also crossed open areas, including the playing fields east of Copnor Road and the golf course to the north of Tangier Road and Burrfields Road. The watching brief monitored ground reduction, landscaping and the excavation of the pipe trench and associated features in a number of locations along the length of the scheme. The monitoring was concentrated on the 'undisturbed' areas of Copnor Road to the north, and the area near Great Salterns Lake to the south, where historic saltworking is known to have taken place. Due to the presence of services, close monitoring was not carried out where the pipe alignment was located within a road. All of the sections were examined for the presence of archaeological features, and available spoil was scanned visually and with a metal detector. No archaeologically significant features or deposits were encountered during the watching brief. Evidence of early 20th century refuse tips was found in the area of works near Great Salterns Lake and Burrfields Road, and Tangier Road. The only finds consisted of three worked flints recovered from spoil to the north of the sports centre off Copnor Road. Copnor Road The monitoring of groundworks in the northern section of the scheme was carried out in the playing fields and sports centre car park to the east of Copnor Road between April and September 2013. Mechanical and manual excavations were undertaken, and the works included topsoil stripping, the excavation of test pits and shafts, and the excavation of the main pipe trench and man-holes. A c.150mm deep topsoil strip for a c.15m wide easement for a new pipeline did not expose any potentially significant archaeological deposits, as it did not go beyond the topsoil horizon. The excavation of the c.2m wide pipe trench was the main element of the scheme to expose any deposits of potential significance. A stratigraphic sequence of deposits was recorded in the areas of groundworks in the playing fields to the north and south of the sports centre. This revealed a simple sequence of topsoil overlying 'natural' silty clay. It was concluded that the shallow depth of the topsoil and absence of a subsoil layer may indicate that the entire area had been systematically landscaped when the playing fields were created. The watching brief on mechanical excavations of the pipe trench in the sports centre car park was abandoned when a large modern soakaway and pipework was uncovered. No archaeological features or deposits were recorded. The only finds were three pieces of struck flint which were recovered from spoil to the north of the sports centre. One flint may be Neolithic or Bronze Age in date. Airport Service Road Groundworks monitored consisted of a trench measuring a maximum of 2m wide and c.2.3m deep was excavated in the carriageway of the road immediately to the north of the northern element of Great Salterns Golf Course. No significant archaeological deposits or features were encountered, and no finds were recovered. Great Salterns Golf Course A watching brief was maintained throughout all groundworks that took place across Great Salterns Golf Course on either side of Burrfields Road. This was due to cartographic evidence of historic saltworking in the area. Groundworks consisted of the excavation of trenches across the golf course and associated outfalls into Great Salterns Lake, and the excavation of a swale across the golf course to the north of Burrfields Road. The pipe trench between Tangier Road and Great Salterns Lake was excavated by mechanical digger and monitored between May and September 2013. The two uppermost layers contained 20th century domestic rubbish. A variety of 20th century rubbish was also encountered during the excavation of one of two outfall shafts, and the excavation of the pipe trench between Great Salterns Lake and Burrfields Road. These deposits indicate the area was used as a refuse tip before the Golf Course was created. This is supported by maps dating to the 1930s which show a processing plant and associated light railway in this area. The use of the area as a clay quarry (information from an elderly resident), long-term modern refuse tip, and the landscaping works associated with the golf course had obscured any evidence which may have related to saltworking. No significant archaeological features or deposits were encountered, and no finds were recovered. Tangier Road Limited monitoring of mechanical excavations in the carriageway of the road took place in May 2013. The underlying deposits in a 4m by 4m shaft were recorded, the road surface having been removed before a site visit took place. The excavation of a 3m deep shaft immediately to the south of Tangier Road was monitored later the same month. The only deposit encountered during both investigations was made ground left from when the area was used as a refuse tip during the 20th century. No significant archaeological features or deposits were encountered, and no finds were recovered. Accession No: 2013/311