In 2011 five boreholes were examined for archaeological reasons in Westgate Gardens in order to investigate the landscape and environment history of this part of the Stour.Three phases of channel activity from the prehistoric to the early medieval period have been illustrated, documenting the development of the channel bar that is today called Bingley’s island.

From the report "A line of power augered boreholes was drilled for archaeological purposes in Westgate
Gardens. The sediments retrieved were recorded and used to understand the
environmental and landscape history of this part of the Stour floodplain. Pollen and plant
macrofossil analysis from selected horizons add to the interpretation and radiocarbon
dating provides the chronological framework. Three phases of channel activity from the
prehistoric to the early medieval period have been illustrated, documenting the
development of the channel bar that is today called Bingley’s island. At the edge of the
bar lay the remnants of late Iron Age iron-working (hammerscale) and burning
(charcoal). Thick wetland peats and soils seal the late prehistoric channel and
landsurface and it is likely that these developed as a result of Roman land use. For
example, the construction of the Roman City wall would have affected the river pattern. It
is possible that the wall obstructed the previously freely flowing river leading to ponding
back as the Stour filled the channel and overflowed onto the floodplain. The waterlogged
ground would have quickly become an established wetland marsh on the approach to
the city. Moorfields Marsh outside the City of London may act as a well-documented
parallel. Here, although poor, drainage was managed by the Romans, but marsh
development began in earnest with the city’s decline. An increase in ploughing following
the Roman conquest, resulting in greater surface water and sediment run-off, would
have contributed to the infilling and clogging up of the river leading to more frequent
flooding. There is also evidence for dumping of human waste adding to the boggy
conditions on the wetland.

The pollen profile produced spans the late prehistoric to early Saxon periods, an episode
for which dated pollen profiles are surprisingly rare in the UK and none currently
published for this area of Kent."

<1> Museum of London Archaeological Service, 2018, Geoarchaeological Geoarchaeological augerhole pilot study at Westgate Gardens (Unpublished document). SKE52380.