archaeological monitoring report
ARCHAEOLOGICAL MONITORING REPORT SCCAS REPORT No. 2010/131
Flood Defence Management Strategy, East Bank Site (Cliff Road), Ipswich IPS 629
HER Information Planning Application No:
IP/09/00345/FUL
Date of Fieldwork:
11th December 2009 – 17th May 2010
Grid Reference:
TM 1704 4314
Funding Body:
Environment Agency
Curatorial Officer:
K. Wade
Project Officer:
M. Sommers
Summary Archaeological monitoring of groundwork associated with improvements to the flood defences of Ipswich along the east bank of the River Orwell, in the area of Cliff Road, was undertaken during the first half of 2010. The works entailed the raising and strengthening of the existing river wall in the area downstream of the Wet Dock and New Cut in advance of the installation of a tidal barrier. Only one aspect was systematically monitored and that was the construction of roadway ramps over the improved flood defence. This entailed a large excavation along the east bank but despite reaching depths of 1.5m below the present ground surface only made ground deposits associated with 19th land reclamation were identified.
1. Introduction and methodology Archaeological monitoring of works associated with the reconstruction and improvement to the flood defences of Ipswich was undertaken during the first half of 2010. These works are part of the Flood Defence Management Strategy (FDMS) for the town of Ipswich and have been commissioned by the Environment Agency with Halcrow Group Limited and Jackson Civil Engineering as the main contractors.
The works were sited on either side of the River Orwell (the East and West Bank work sites) immediately to the south of the entrance to the Wet Dock and the mouth of the New Cut (See Fig. 1). This work is part of an ongoing project to create a movable tidal barrier across the mouth of the New Cut to prevent tidal surges flooding areas of the town located further up river. Prior to the installation of the tidal barrier it was necessary to improve the existing downstream flood defences. These works entailed the creation of a combination of brick clad reinforced concrete walls and brick clad sheet-piles and road raising and realignment in the Cliff Road/Cliff Quay area.
The areas subject to the works are on the foreshore of the tidal River Orwell., immediately to the south of the Area of Archaeological Importance defined for the historic town of Ipswich in the County Historic Environment Record. There has been 1
Norfolk
SUFFOLK
Essex
0
25km
0
0.5
1km
243400
WEST BANK SITE
EAST BANK SITE
243200
243000
242800
0
TM
200
400m
©Crown Copyright. All Rights Reserved. Suffolk County Council Licence No. 100023395 2010
Figure 1. Site location plan
2
617400
T CU
WET DOCK
617200
617000
616800
W NE
616600
616400 243600
N
little archaeological work undertaken in these areas and consequently the potential of the archaeological resource liable to be affected by the FDMS scheme is unknown. The estuarine nature of the site has the potential to yield deeply buried deposits from any period which and may include timber structures such as jetties or wharfs, revetment structures, and possibly the remains of hulked ships/boats. In light of this potential an archaeological condition (PPG 16, para. 30) was attached to the planning consent calling for archaeological monitoring of groundwork associated with the proposed works.
The monitoring was achieved through the visual examination of the footing trenches to identify archaeological features and/or deposits. The resultant spoil was also briefly examined in order to recover datable artefacts. A small number of digital photographs were taken as part of the record.
2. Results The East Bank works site was visited on seven separate occasions between December 2009 and May 2010 to inspect the works underway.
During the initial visit the method for the replacement of the existing flood defence was observed. It was noted that the old concrete wall at the top of the riverbank was grubbed out leaving a trench c. 1.4m wide and 1m deep. In the area where this was observed, this trench was entirely in relatively recent (19th/20th century) made ground deposits (Plate I). Following the grubbing out of the old wall the new flood defence, which comprised large sheet-piles, were vibrated in. Given the limited amount of disturbance, most of which occurred in a linear zone already disturbed by the construction of the old flood defence, it was deemed extremely unlikely that any significant archaeological deposits or remains would be exposed and as such this aspect of the work would not require further monitoring. If a sheet-pile could not be driven due to the presence of an underground obstacle excavation would be required to expose the obstacle in order to remove it. Such work would entail the potential to reveal or damage buried archaeological deposits and /or remains and as such would require archaeological monitoring, although in actuality, this did not occur during the project. 3
It was quickly realised that the only component of the East Bank works that had a real potential to reveal archaeological deposits was the excavation of the foundations for the road way where it passes over the new wall. This would entail the excavation of an area c. 11m wide and 80m in length running approximately parallel with the river bank (Fig 2).
CL
IFF
RO
AD
N
NEW FLOOD DEFENCE
ROADWAY RAMPS
0
50
100m
©Crown Copyright. All Rights Reserved. Suffolk County Council Licence No. 100023395 2010
Figure 2. Site plan
The area excavated for the roadway ramps was cut to a depth of c. 1.5m from the existing ground surface (Plate II). In general the excavation cut through an overburden of dirty dark loam with modern debris to a depth of c. 0.4m which in turn overlay 0.6m thick deposit of clean chalk (Plate III). This in turn overlay a yellow sand and gravel with chalk lumps although the thickness of these layers varied across the length and width of the excavation. The chalk deposit was thicker towards the river. In an east-west section (Plate IV) the base of the chalk could be clearly seen to step down resulting in a substantial thickening of the layer. In zones close to the eastern edge of this excavation the chalk deposit was missing entirely with the dirty dark loam, with red brick rubble and other debris, forming the entire bulk of the material removed (Plate V). The stubs of two wooden piles were noted in the base of the
4
excavation, close to the western edge. Each was c. 0.3m square and vertically placed (Fig 3, also visible in Plate V).
N
ramp excavation
wooden piles
0
15
30m
Figure 3. Location of wooden piles The works on the West Bank site were not monitored as the work primarily entailed the driving of sheet-piles with only shallow excavation. No deep excavations to remove buried obstacles were required.
The remains of two barges were noted on the East Bank foreshore (Plate VI), but neither was under threat from the works undertaken.
3. Conclusion There is documentary evidence, primarily map based, that the areas of both the West and the East Bank work sites were reclaimed during the post-medieval period. A plan of the River Orwell dated 1804 (Fig. 4) shows the site of Cliff Brewhouse, on the east bank, to be on an area described further to the right as ‘gravelly beach’ whilst the west bank area lies within an area defined as ‘embanked marsh’. 5
West Bank site
East Bank site
Figure 4. Plan of the River Orwell dated 1804
(with the approximate locations of the East and West Bank sites arrowed)
6
N
EA ST
BA
NK
W
SIT
E
ES TB AN
K
SIT
E
NEW CUT
WET DOCK
Figure 5. 1st Edition Ordnance Survey map of 1887 (un-scaled extract)
This is reflected in the deposits observed in the excavation of the foundation slab for the roadway ramps on the East Bank site. These deposits clearly demonstrate that substantial amounts of material had been dumped, presumably behind some form of retaining structure to extend the land over what would have formerly been mud flats and the gravelly beach, as marked in the 1804 plan. The thick deposit of chalk has been used to consolidate the underlying deposits and so create a firm and level surface. A later plan of 1836 shows the both the East and West banks areas have not significantly changed although by the 1st Edition map of 1887 (Fig. 5) the railway has been built along the West Bank and a strip of land, at least 30m in width, runs across the front of the brewery. The evidence shown on these two surveys indicates a substantial reclaiming of land in the second half of the 19th century, presumably in response to the greater wealth and industrial activity in Ipswich following the construction the Wet Dock in the 1842.
M. Sommers July 2010
7
4. Plates
Plate I. Grubbing out of existing flood wall
Plate II. Excavation for the roadway ramp foundation 8
Plate III. Layers of made ground showing the thick deposit of chalk, view looking east
Plate IV. Layers of made ground, view looking south
9
Plate V. Made ground along eastern edge of roadway ramp foundation
Plate VI. Hulks adjacent to the East Bank site, view looking southwest
10
Flood Defence Management Strategy, East Bank Site (Cliff Road), Ipswich IPS 629
HER Information Planning Application No:
IP/09/00345/FUL
Date of Fieldwork:
11th December 2009 – 17th May 2010
Grid Reference:
TM 1704 4314
Funding Body:
Environment Agency
Curatorial Officer:
K. Wade
Project Officer:
M. Sommers
Summary Archaeological monitoring of groundwork associated with improvements to the flood defences of Ipswich along the east bank of the River Orwell, in the area of Cliff Road, was undertaken during the first half of 2010. The works entailed the raising and strengthening of the existing river wall in the area downstream of the Wet Dock and New Cut in advance of the installation of a tidal barrier. Only one aspect was systematically monitored and that was the construction of roadway ramps over the improved flood defence. This entailed a large excavation along the east bank but despite reaching depths of 1.5m below the present ground surface only made ground deposits associated with 19th land reclamation were identified.
1. Introduction and methodology Archaeological monitoring of works associated with the reconstruction and improvement to the flood defences of Ipswich was undertaken during the first half of 2010. These works are part of the Flood Defence Management Strategy (FDMS) for the town of Ipswich and have been commissioned by the Environment Agency with Halcrow Group Limited and Jackson Civil Engineering as the main contractors.
The works were sited on either side of the River Orwell (the East and West Bank work sites) immediately to the south of the entrance to the Wet Dock and the mouth of the New Cut (See Fig. 1). This work is part of an ongoing project to create a movable tidal barrier across the mouth of the New Cut to prevent tidal surges flooding areas of the town located further up river. Prior to the installation of the tidal barrier it was necessary to improve the existing downstream flood defences. These works entailed the creation of a combination of brick clad reinforced concrete walls and brick clad sheet-piles and road raising and realignment in the Cliff Road/Cliff Quay area.
The areas subject to the works are on the foreshore of the tidal River Orwell., immediately to the south of the Area of Archaeological Importance defined for the historic town of Ipswich in the County Historic Environment Record. There has been 1
Norfolk
SUFFOLK
Essex
0
25km
0
0.5
1km
243400
WEST BANK SITE
EAST BANK SITE
243200
243000
242800
0
TM
200
400m
©Crown Copyright. All Rights Reserved. Suffolk County Council Licence No. 100023395 2010
Figure 1. Site location plan
2
617400
T CU
WET DOCK
617200
617000
616800
W NE
616600
616400 243600
N
little archaeological work undertaken in these areas and consequently the potential of the archaeological resource liable to be affected by the FDMS scheme is unknown. The estuarine nature of the site has the potential to yield deeply buried deposits from any period which and may include timber structures such as jetties or wharfs, revetment structures, and possibly the remains of hulked ships/boats. In light of this potential an archaeological condition (PPG 16, para. 30) was attached to the planning consent calling for archaeological monitoring of groundwork associated with the proposed works.
The monitoring was achieved through the visual examination of the footing trenches to identify archaeological features and/or deposits. The resultant spoil was also briefly examined in order to recover datable artefacts. A small number of digital photographs were taken as part of the record.
2. Results The East Bank works site was visited on seven separate occasions between December 2009 and May 2010 to inspect the works underway.
During the initial visit the method for the replacement of the existing flood defence was observed. It was noted that the old concrete wall at the top of the riverbank was grubbed out leaving a trench c. 1.4m wide and 1m deep. In the area where this was observed, this trench was entirely in relatively recent (19th/20th century) made ground deposits (Plate I). Following the grubbing out of the old wall the new flood defence, which comprised large sheet-piles, were vibrated in. Given the limited amount of disturbance, most of which occurred in a linear zone already disturbed by the construction of the old flood defence, it was deemed extremely unlikely that any significant archaeological deposits or remains would be exposed and as such this aspect of the work would not require further monitoring. If a sheet-pile could not be driven due to the presence of an underground obstacle excavation would be required to expose the obstacle in order to remove it. Such work would entail the potential to reveal or damage buried archaeological deposits and /or remains and as such would require archaeological monitoring, although in actuality, this did not occur during the project. 3
It was quickly realised that the only component of the East Bank works that had a real potential to reveal archaeological deposits was the excavation of the foundations for the road way where it passes over the new wall. This would entail the excavation of an area c. 11m wide and 80m in length running approximately parallel with the river bank (Fig 2).
CL
IFF
RO
AD
N
NEW FLOOD DEFENCE
ROADWAY RAMPS
0
50
100m
©Crown Copyright. All Rights Reserved. Suffolk County Council Licence No. 100023395 2010
Figure 2. Site plan
The area excavated for the roadway ramps was cut to a depth of c. 1.5m from the existing ground surface (Plate II). In general the excavation cut through an overburden of dirty dark loam with modern debris to a depth of c. 0.4m which in turn overlay 0.6m thick deposit of clean chalk (Plate III). This in turn overlay a yellow sand and gravel with chalk lumps although the thickness of these layers varied across the length and width of the excavation. The chalk deposit was thicker towards the river. In an east-west section (Plate IV) the base of the chalk could be clearly seen to step down resulting in a substantial thickening of the layer. In zones close to the eastern edge of this excavation the chalk deposit was missing entirely with the dirty dark loam, with red brick rubble and other debris, forming the entire bulk of the material removed (Plate V). The stubs of two wooden piles were noted in the base of the
4
excavation, close to the western edge. Each was c. 0.3m square and vertically placed (Fig 3, also visible in Plate V).
N
ramp excavation
wooden piles
0
15
30m
Figure 3. Location of wooden piles The works on the West Bank site were not monitored as the work primarily entailed the driving of sheet-piles with only shallow excavation. No deep excavations to remove buried obstacles were required.
The remains of two barges were noted on the East Bank foreshore (Plate VI), but neither was under threat from the works undertaken.
3. Conclusion There is documentary evidence, primarily map based, that the areas of both the West and the East Bank work sites were reclaimed during the post-medieval period. A plan of the River Orwell dated 1804 (Fig. 4) shows the site of Cliff Brewhouse, on the east bank, to be on an area described further to the right as ‘gravelly beach’ whilst the west bank area lies within an area defined as ‘embanked marsh’. 5
West Bank site
East Bank site
Figure 4. Plan of the River Orwell dated 1804
(with the approximate locations of the East and West Bank sites arrowed)
6
N
EA ST
BA
NK
W
SIT
E
ES TB AN
K
SIT
E
NEW CUT
WET DOCK
Figure 5. 1st Edition Ordnance Survey map of 1887 (un-scaled extract)
This is reflected in the deposits observed in the excavation of the foundation slab for the roadway ramps on the East Bank site. These deposits clearly demonstrate that substantial amounts of material had been dumped, presumably behind some form of retaining structure to extend the land over what would have formerly been mud flats and the gravelly beach, as marked in the 1804 plan. The thick deposit of chalk has been used to consolidate the underlying deposits and so create a firm and level surface. A later plan of 1836 shows the both the East and West banks areas have not significantly changed although by the 1st Edition map of 1887 (Fig. 5) the railway has been built along the West Bank and a strip of land, at least 30m in width, runs across the front of the brewery. The evidence shown on these two surveys indicates a substantial reclaiming of land in the second half of the 19th century, presumably in response to the greater wealth and industrial activity in Ipswich following the construction the Wet Dock in the 1842.
M. Sommers July 2010
7
4. Plates
Plate I. Grubbing out of existing flood wall
Plate II. Excavation for the roadway ramp foundation 8
Plate III. Layers of made ground showing the thick deposit of chalk, view looking east
Plate IV. Layers of made ground, view looking south
9
Plate V. Made ground along eastern edge of roadway ramp foundation
Plate VI. Hulks adjacent to the East Bank site, view looking southwest
10
