Reasons for Designation
Romano-British canals were used for inland transport and/or the control
and diversion of water. Current understanding suggests that some may have
been only partly navigable, their function as water control systems being
at least as important as their transport role. Generally some canals
appear to have been dug in straight sections, with angular bends at the
junctions, while others were created by straightening and deepening
existing natural watercourses. The upcast from digging was piled up to
form banks on one or both sides of the channel. Causeways are known to
have crossed the canals, some built as an integral part of the
construction, others created by later filling-in of the channel.
There is some uncertainty about the precise dates of Romano-British
canals, but present evidence suggests that their construction and use
mainly spanned the 2nd to 4th centuries. Some appear to have been filled
or silted up at the end of this period, although there is evidence that
some continued in use for transport during the medieval period.
All known examples of Romano-British canals in England are located in
similar topographic positions within the low-lying Fenland areas of
eastern England. The canals vary greatly in length, from small examples
around 6km in length, to the most famous system, known as the Car Dyke,
which stretches some 92km between Lincoln and Peterborough. Although these
canals can be traced over distances of many kilometres, few sections
retain the full range of original construction features. They are
recognizable as earthworks or as cropmarks on aerial photographs, or as a
combination of both. All known lengths, where significant archaeological
deposits are likely to survive, are considered worthy of protection.
The Car Dyke is the largest of the known Romano-British canals, stretching
from the River Witham in the north to the River Nene in the south. First
recognised by antiquaries in the early 18th century, it forms an important
feature of the Roman landscape in the Fens. Although some sections are no
longer visible and much of its length has been incorporated into modern
drainage systems, sufficient evidence does exist for its route to be fairly
accurately identified from Washingborough, 4km east of Lincoln, to 1.5km
east of Peterborough, a distance of approximately 92km. It was originally
thought to continue south of Peterborough to the Waterbeach canal, north
east of Cambridge, but no link has been proven. The Car Dyke survives in a
variety of conditions, at its most complete taking the form of a wide
channel flanked by parallel banks. It is more often visible as low
earthworks or as cropmarks, identified from aerial photographs. It is
clearly influenced by the local topography, taking a sinuous route in the
northern portion, at the boundary between the fens and the upland. The
central portion, south of Billinghay to Market Deeping, the canal takes
a more direct route across relatively flat land, at about the 4m to 5m
contour. The southern part of the route generally follows the 5m contour,
again skirting the upland, with the exception of a short section near Eye
where it cuts through a ridge, rather than following the more circuitous
contour line. It has been suggested that the angular bends along the route
are evidence that it was excavated in sections, the bends occuring where
separate lengths met.
Traditionally, the Car Dyke has been regarded as a means of transportation,
created in the 2nd century, and more recently as a catchwater drain, although
firm archaeological evidence for the construction date and use of the canal in
its original form is sparse. It has been suggested that the presence of
unexcavated causeways along its route make it impractical as a navigable
waterway. However, the undug causeways may have served to maintain differing
water levels in the separate channels and long stretches of the route would
still have been navigable. As a catchwater drain, the channel could have
collected and diverted water from the uplands to limit flooding of the
Fenland, although no evidence of a wider drainage scheme has been identified.
It has also been suggested that the Car Dyke formed a boundary delimiting an
imperial estate centred on the Fens, although it is not clear how such a
boundary would have functioned. It may have served one or more of these
functions at any one time. The size and extent of the dyke implies
considerable expenditure of labour and resources, whether military or civilian
in origin. In places the canal appears to have silted up and fallen into
disuse by the end of the Roman period, although its route, at the Fen edge,
may have been subsequently utilised as a boundary. The Car Dyke is first
mentioned in early medieval documents, when parts of it served as a
boundary, and there is evidence that at least one section of the canal was
being used for transport in the 14th century.
Barrows are funerary monuments dating from the Late Neolithic period to the
Late Bronze Age. They were constructed as earthen or rubble mounds, sometimes
ditched, which covered single or multiple burials. They occur in isolation or
grouped as cemeteries and provide information on the diversity of beliefs and
social organisation amongst early prehistoric communities.
A fishpond is an artificially created pool of slow moving freshwater
constructed for the purpose of cultivating, breeding and storing fish to
provide a constant and sustainable food supply. They may be dug into the
ground, embanked above ground level, or formed by placing a dam across a
narrow valley. Fishponds were maintained by a water management system which
included inlet and outlet channels carrying water from a river or stream, a
series of sluices and an overflow leat which controlled fluctuations in the
water flow. The tradition of constructing and using fishponds in England began
during the medieval period and peaked in the 12th century. They were largely
built by the wealthy sectors of society with monastic institutions and royal
residences often having large and complex fishponds.
The section of the Car Dyke canal, barrows and fishponds 250m north west
of the Old Rectory survive well as a series of earthwork and buried remains.
Deposits in the barrow ditches, the Car Dyke water channel and fishponds will
contain information on their construction and use and evidence for the local
environment during their period of use. Soils buried beneath the banks will
preserve evidence of landuse prior to their construction. The barrows, Car
Dyke and fishponds will contribute to our understanding of the development of
the prehistoric, Roman and medieval landscapes.
Details
The monument includes the remains of a section of the Roman artificial
watercourse or canal known as the Car Dyke, together with two fishponds and
two ring ditches, or barrows, 250m north west of the Old Rectory. The Car
Dyke is part of a linear, north-south canal system which stretches from
Lincoln to Peterborough. This section of the Car Dyke follows a slightly
sinuous course, from east to west, at the southern edge of the fen. It is
visible as a channel, flanked by a parallel earthen bank on its north side,
for a distance of approximately 580m. To the south east the course of the Car
Dyke is overlain by modern development and is not included in the scheduling.
The eastern portion of the channel is visible as a broad, dry hollow
measuring approximately 15m in width crossing open ground. About 200m from
the east end the channel forms part of the drainage system and is visible as
a fairly steep sided channel which measures 12m in width and up to 1.5m deep,
narrowing to 7m in width at the western end. The bank flanking the north side
of the channel measures between 20m and 30m in width and stands up to 1.5m
high along part of its length. To the west the bank is no longer visible and
is not included in the scheduling.
The southern edge of the channel is marked by a counterscarp, cutting the
higher ground to the south, rising up to 1.75m above the base of the channel.
Earlier descriptions note a low bank surviving in places along the south side
of the channel, although it is no longer visible.
Two circular cropmarks, or ring ditches, visible on aerial photographs are
located at the western end of, and immediately adjacent to, the south side of
the Car Dyke. The cropmarks, measuring approximately 35m and 20m in diameter,
are thought to indicate the buried remains of Bronze Age round barrows and
are included in the scheduling.
Two embanked enclosures, believed to represent medieval fishponds, are located
on low-lying ground immediately adjacent to the north bank of the Car Dyke and
bounded to the north by an eastward flowing stream. The ponds, aligned east-
west, are subrectangular in plan, measuring 50m by 30m and 70m by 30m. The
ponds are surrounded by low banks raised above the general ground level,
measuring between 2m and 6m in width. A shallow channel, part of the former
water management system, separates the two ponds and follows a course on the
south side of the eastern pond, at the foot of the Car Dyke bank.
All fence posts and water troughs are excluded from the scheduling,
although the ground beneath them is included.
MAP EXTRACT
The site of the monument is shown on the attached map extract.
