In 1972 Oxfordshire Archaeological Unit excavated a 40 acre site at the south-west end of 'Cumnor Meadow' prior to the construction of the second reservoir by Thames Water. The meadow was recorded in the Domesday Book as covering 200 acres and remained as pasture until the 1930s when parts were exploited for gravel extraction. The excavation was undertaken on the evidence of cropmarks and yielded information on the enviroment and economy in four periods. It also led to the identification of more than 300 insect species, 125 plant species and 30 snails.
The site included part of the Thames alluvial floodplain and the slightly raised first gravel terrace, just north of Lower Whitley. Excavation on the wide gravel terraces to the west of the Thames at Stanton Harcourt, Eynsham and Cassington had already revealed many important prehistoric sites.
The first settlement evidence found at Farmoor was dated 600-500 B.C. It was represented only by a group of storage or rubbish pits on the higher level, and signs of a wattle and daub building and small-scale iron-working.
The second period for which evidence emerged was 500-300 B.C., with changes in the settlement pattern and pottery finds from the first period indicating a gap in site occupation. Three farmsteads were located, with small, ditched enclosures for round houses and stock pens. These were situated in the open, wet grassland and were subject to winter flooding from the Thames. The economy was pastoral and seasonal, an unusual feature for known Iron Age sites. The farmsteads appeared to have been occupied only for a few years.
The third period was the 100-200 A.D., marked by further changes after another break in site occupation. The floodplain remained unenclosed but without evidence of occupation, which had apparently shifted onto the better-drained terrace. Small fields, probably enclosed with thorn hedges, were aligned with a droveway leading onto the meadow. The small fields may have been used for stock management, while the meadow provided hay and grazing. The broken blade of a large hay scythe was found near the droveway. One find of considerable interest was a double horse burial, which might represent ritual practice.
It was suggested that the differences between the Iron Age and Romano-British settlement may have resulted from changes in tenure, with the latter perhaps being part of a larger farm or estate.
It is possible that the droveway continued soutward to take the line followed later by the track leading up from Lower Whitley to the Cumnor ridge. The ditch running eastward between the meadow and the higher terrace became the boundary between Stroud and Whitley tithings and is mentioned in the Saxon boundary charter BCS 1222, the 'ealden dic' after 'Wadleahe'.
In Medieval times much of terraced site was converted to arable, though the floodplain remained a common meadow on which manorial tenants held rights until the 19th century. The terrace arable would have been farmed by Whitley tenants.
(Further reading: Lambrick & Robinson, 'Iron Age and Roman riverside settlements at Farmoor, Oxfordshire', O.A.U. 1979)