Case Study Site 7 – West Bay to Lyme Regis, Dorset

Case Study Site 7 – West Bay to Lyme Regis, Dorset

1.         Location

The case study extends along the south Dorset coast from West Bay in the east (to the south of Bridport), westwards for a distance of approximately 10km to Lyme Regis.  The location lies within the East Devon-Dorset Jurassic Coast World Heritage Site. 

2.         Why was the Case Study Site selected?

This is a dynamic coastline affected by a range of erosional, instability and sediment transportation issues.  This coastline contains a rich heritage in terms of both built and buried features.  These include the historic harbour at West Bay (Bridport Harbour) and its Conservation Area, cliff top sites extending along the frontage past Seatown to Charmouth, and at Lyme Regis the historic waterfront and the harbour arm known as The Cobb.  The picturesque nature of this coastline and the dramatic landslide processes attracted artists and geologists in the late eighteenth and nineteenth centuries and, as a result, there are numerous images of this frontage, which illustrate this changing coast over time. 

3.         Summary of the Geology, Geomorphology & Coastal Processes

The coastal geology is dominated by the famous Lias Group of mudstones and limestones of the early Jurassic epoch, which are overlain by the Chalk.  The Lias forms the dramatic cliffs to the west of the town of Lyme Regis, with parts of the exposures being obscured by the extensive landslide systems at Bindon and Downlands (Conybeare & Dawson, 18401). 

The landslides along the coastal cliffs are composed of Jurassic clays and limestones with the tops of the cliffs at Black Ven, Stonebarrow and Golden Cap being capped by Upper Greensand.  The combination of rapid coastal erosion and ground instability as a result of rainfall percolation and loss of support at the toe of the cliff has resulted in the dramatic coastal landscape. 

The general direction of sediment transport is from west to east, as far as the harbour arms at West Bay.  Here there is interruption to the sediment pathway and some transport movements both offshore and east to west before resuming an easterly direction on towards East Dorset.  The eroding cliffs contribute substantial amounts of sediment to the overall system. 

4.         Risks to Heritage Assets along the Case Study Frontage

Atlantic storm waves attack the Lyme Bay frontage, causing rapid rates of erosion and promoting instability.  Whilst heritage sites at West Bay and Lyme Regis have been protected and upgraded in recent years, much of the open coast remains undefended.  Here, heritage assets located along the top of the soft cliffs and in the immediate coastal hinterland are vulnerable to the rapid rates of coastal retreat, which are likely to accelerate in the future. 

5.         How can historical Imagery inform heritage risk management?

The views illustrated below depict this highly varied coastal frontage at various points in time.  They depict the nature of the coastal structures such as the harbour at West Bay (Figures 7.1 and 7.2) and The Cobb at Lyme Regis (Figures 7.14-7.16) in the early nineteenth and early twentieth centuries.  Further views show the character of the foreshore at Charmouth (Figures 7.3 and 7.4) and the cliff top landscapes over the same time period (Figures 7.5-7.7 and 10).  The images also illustrate the changing patterns of development since the 1840s (Figures 7.11-7.13). 

Figure 7A: ‘View of Lyme Regis from the East’.  Mid-nineteenth century lithograph.

Figure 7.1: ‘Bridport Harbour’ or West Bay by William Daniell RA. 1825. The aquatint engraving shows how the historic harbour arms cross the wide beach interrupting the west to east sediment transport along the coast.

Figure 7.2: This view of the same scene (but from a lower vantage point) was painted in watercolour by David Addey in 1990.  The harbour and flood defences were improved ten years ago.

Image Courtesy of David Addey.

Figure 7.3: ‘Lyme Regis from Charmouth’ by William Daniell RA. 1825. Lyme Regis was a small resort at this time.  The view in Figure 7.4 by David Addey (1990) shows the extensive beach at Charmouth at Low Tide.  Daniell’s view was taken from the stone building on the right of the picture. 

Image Courtesy of David Addey.

Figures 7.5 and 7.6: An extensive view along the cliff top from Charmouth looking eastwards by Alfred Robert Quinton, c.1920.  The cliff tops contain numerous buried heritage sites, which are exposed through rapid coastal erosion and landsliding (e.g. Dog House Hill, Chideock MDO7655).

Image Courtesy of J. Salmon Limited of Sevenoaks.

Figure 7.7: A panoramic view of the coast from above Lyme Regis past The Spittles, Stonebarrow Hill, Charmouth and Golden Cap by G. Hawkins, c.1830.

Figure 7.8: The coastal geology and geomorphology was mapped and described by the Rev. W. Conybeare and William Dawson in 1840.  They provided detailed maps of the landslips, as well as finely lithographed views of the major landslide events.

Image Courtesy of Dorset County Museum and Heritage Service. 

Figure 7.9: In addition to their maps and plates, Conybeare and Dawson produced detailed views of the coastline from the sea, which provide an accurate record of coastal conditions and developments along this part of the East Devon/West Dorset coast.

Image Courtesy of Dorset County Museum and Heritage Service. 

Figure 7.10: ‘Above Lyme Regis Looking Across Marshwood Vale, Dorset’ by Thomas Girtin. Watercolour, c.1797. Girtin’s view illustrates, in colour, the nature of the cliff top landscape of West Dorset two hundred and twenty years ago. 

Image Courtesy of Christie’s.

Figure 7.11: A fine lithograph of the beach at Lyme Regis by Daniel Dunster.  Lithograph. C.1840.

Image Courtesy of Lyme Regis Museum.

Figure 7.12: A mid-nineteenth century view looking over the developing town of Lyme Regis from the east side close to Black Ven.  The unstable nature of the coastal cliffs can be seen in the foreground.

Image Courtesy: Private Collection.

Figure 7.13: Lyme Regis has been protected progressively over the last twenty-five years with several phases of major coast protection and landslide stabilisation works.  These have included the addition of rock armour at the end of The Cobb and, more recently, further works at the eastern end of the seafront below The Spittles.

Image Courtesy of the Wight Light Gallery. 

6.         Key Issues – What can be learnt from this site?

The images show that key structures such as West Bay Harbour and The Cobb at Lyme Regis appear to have changed little over the last 250 years.  The structures have been upgraded and strengthened to meet the coast protection needs, for example at West Bay between 2002 and 2004, and, progressively, works have been undertaken along the Lyme Regis frontage over the last fifteen years. 

The case study site shows how heritage, such as coastal Conservation Areas including listed buildings, can be protected if the measures required are economically justifiable and environmentally sustainable.  However, long sections of this coast are likely to see the continuing erosion of the cliffline and increased exposure and loss of cliff top heritage. 

Figure 7.14: ‘The Cobb, Lyme Regis’, c.1890 by Charles Robertson RWS.  This was one of at least two watercolours that he painted of Lyme.  Robertson was a follower of the Pre-Raphaelites and, as a result, his watercolour drawings are both detailed and accurate. 

Image reproduced by kind permission of Sidmouth Museum.

Figure 7.15: ‘The Cobb, Lyme Regis’ by Alfred Robert Quinton, who painted numerous watercolours of the town and seafront in the 1920s.  The quality and detail of Quinton’s work is obvious and compares favourably with the black and white photographic postcard published at about the same time (Figure 7.16). 

The advantages of images in colour in terms of describing the coastal architecture and the construction of The Cobb can be readily appreciated. 

Image Courtesy of J. Salmon Limited of Sevenoaks. 

7.         References

1.         Conybeare, Rev. W. & Dawson, W., 1840. Memoir and Views of the Landslips on the East Devon & c.