Annex 02: Slapton

Location Description Geomorphological Biological Site issues The Shingle Bar The Road The Lagoon Others Experience Hallsands village Hallsands Hotel Beesands The future of the A379 References
	Torcross village, July 2001, waves reached to the top of the houses during a storm in January 1979

Site Name: - Slapton Sands

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Location

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Description

The site here referred to as Slapton Sands lies within a bay complex and includes Slapton Ley Site of Special Scientific Interest (SSSI), a freshwater lagoon and shingle bar. The lagoon forms part of the SSSI, which is also a National Nature Reserve, managed and used by the Field Studies Council ( http://www.field-studies-council.org/ ) as an ‘outdoor laboratory’. The shingle bar, shown in the picture on the front page, encloses and protects the lagoon from tidal inundation and stretches from Torcross (GR: SX 823417) to Strete Gate (GR: SX 845465).

Figure, Slapton 01: The location of Slapton Sands in relation to Start Bay. Additional information derived from Barne et al. (1996)

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Geomorphological setting

This site forms part of an embayment which is enclosed by Start Point in the south and the River Dart to the northeast. Offshore the sea floor shelves gradually to 20m and is composed mostly of Quaternary deposits. The area represents a sub-cell lying within the coastal cell 6 (Figure 09-01). There is a drift divide at Start Point, whilst the drift movement within the sub-cell has a variable net drift direction, shown by the arrows (Figure Slapton 01 opposite). The tidal range is approximately 4m at mean spring tides. A narrow shingle beach is present along much of the coast, protecting low-lying land in the vicinity of Slapton Ley from flooding. The rest of the coast is composed of rising land and resistant rocks.

Along much of its length the beach is composed of small sized pebbles (Figure Slapton 02 below) and includes an elongated shingle bar extending for a distance of approximately 3 kilometres between Torcross and Strete Gate. The bar was formed in post-glacial times when it dammed a former estuary and now encloses a freshwater lagoon. The shingle bar is a nationally important example of a bay bar. It demonstrates better than many other sites around the British coast the links between seabed features and shoreline landforms, both in their glacial history and their effects upon modern-day wave behaviour.  

Figure, Slapton 02: Size of shingle on the beach at Slapton. The scale is provided by a 50p piece and shows the pebbles to be at the lower end of the range for shingle.

Figure, Slapton 03: The thin ‘ribbon’ of shingle preventing flooding of Slapton Ley by the sea

Slapton Sands shingle bar is effectively a relict feature which was formed in immediate post-glacial times by the ‘Flandrian Transgression’ (post-glacial sea level rise) which pushed the predominantly flint and quartz shingle ridge onshore. The present shingle ridge and lagoon is the result of a 10,000 year progression which continues today. The location of the bar in relation to the Ley (lagoon) is shown in Figure Slapton 03.

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Biological setting

The wetland is spilt into two sections: Lower Ley, to the south, is mostly open water with a rich macrophyte flora fringed by reedbeds; Higher Ley, to the north, consists largely of rich fen and willow carr vegetation. These habitats support a very diverse flora and fauna. The lagoon supports a wide variety of habitats and possesses a rich and diverse flora and fauna. It is of particular importance for lichens, fungi and invertebrates and for passage and wintering birds. Over 490 species of vascular plant have been recorded, including one national rarity. The shingle bar has been colonised by a characteristic plant community dominated by Sea Radish Raphanus maritimus, and which includes Ray’s Knotgrass Polygonum oxyspermum, Yellow-horned Poppy Glaucium flavum, and Viper’s Bugloss Echium vulgare.

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Site issues

This site highlights a general problem associated with maintaining a fixed development (in this case a road) on a geomorphological structure that it appears will continue to adjust to tidal/climatic forces. Coupled with this is the extent, to which the features for which the site has been established, namely coastal shingle, coastal shingle vegetation and a freshwater lagoon will be maintained in the face of a continued movement - ‘roll-over’ landward - of the shingle bar.

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The shingle bar

The evolution of the shingle bar suggests that it will continue to migrate landward. This would seem to be part of a long-term trend which may have been accelerated with the removal of approximately 650,000 tons of shingle offshore, mostly from ‘Skerries Bank’ in the latter part of the 19^th Century. This appears to have led to the loss of the small fishing village of Hallsands, which has been documented in several publications (Harvey undated; Barber 2001; Melia 2002). The closure of the Hallsands Hotel and the progressive building of coastal defences at Beesands and along the foreshore of Slapton Sands (Figure Slapton 04 below) may all be part of the same story.  

	Figure, Slapton 04: Picture 1 Shingle beach in June 1990 looking south towards the central car park in the distance at GR SX 829442.
	Figure, Slapton 04: Picture 2 The situation in August 2002 when the eroding shingle beach had apparently dropped several metres, looking south from GR SX 829443 (note the height of the car park and the ‘protective’ structures in relation to the beach).

As the shingle beach erodes the vegetation on the shingle ridge is lost. The lower beach levels suffer from increased tidal action and vegetation growth is restricted. Unless the ridge is allowed to ‘roll-over’ then the shingle is ‘squeezed’ against the road. This prevents the ridge from moving landward and limiting the creation of new vegetated shingle to landward.

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The road

The A379 provides the principle means of access to this part of the coast from both Dartmouth in the northeast and Kingsbridge in the west. It is the most direct access to Dartmouth for Torcross residents and a through route for tourists. There is an apparent social and economic imperative to keep the road open and at the northern end, where the road had become undermined by the eroding beach it has been moved inland in response (see Figure Slapton 05 opposite).  

Figure, Slapton 05: The old, and ‘new road’ to landward, looking north from near the same location as Picture 1, GR SX 829443. [Note: just a year after being reopened storms, which battered the coast along Slapton Sands closed the main A379 road for one day, on Thursday 14th March 2002.]

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The lagoon

The lagoon plants and animals are dependent on the freshwater nature of the water within it. Any breach of the shingle bar could introduce saline water, which would in turn alter the species composition. Even if no breach occurs any ‘roll-over’ of the bar would diminish the area of the lagoon. The effect of this on the interest for which the site is established as a National Nature Reserve is an important consideration.  

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Other Issues

An issue possibly specific to this site is the problem associated with the charity status of the owners of the site. The reserve is leased to the Field Studies Council from The Whitley Wildlife Conservation Trust, which promotes education and conservation through its ownership of Slapton Ley and Paignton Zoo Environmental Park. It is not clear if a policy which accepts loss of land with Charitable Status as a result of the removal of the road and subsequent ‘roll-over’ of the shingle would be condoned by the Charity Commissioners!?

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Experience - the wider picture

Looking at Slapton Sands in isolation might suggest that protecting the coast is a feasible and sustainable option. However looked at from a wider perspective it appears that there has been a tendency for the shingle beaches to erode around the periphery of Start Bay. It is not altogether clear if this is a relatively recent phenomenon, brought about in part by human actions or part of a long-term trend. The evidence from Hallsands suggests that the beaches have always waxed and waned, though the loss of offshore shingle due to human interference seems to have tipped the balance to one of overall erosion. What seems certain is that there is little new sediment entering the bay (see Futurecoast quote below). Two other sites are used below to illustrate the trend, Hallsands Hotel and Beesands.

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Hallsands – the end of a fishing village

The fate of the Hallsands, a fishing village in south Devon, with some 37 houses and 128 inhabitants was sealed in 1897 when work began on the construction of Devonport docks for the Royal Navy. Large quantities of stone were needed, which appeared to be present in abundance offshore on the ‘Skerries bank’ in nearby Start Bay (Figure Slapton 01 above). Because of the potential effects to sea defences protecting nearby land, the terms of the licence included a clause allowing the licence to be revoked at short notice. By 1900 the villagers of Hallsands noticed, as they anticipated, that the beach protecting the houses had begun to disappear. Damage to the houses resulted in the licence eventually being cancelled in 1902. By then the damage was done and despite a respite for approximately 13 years, a storm in January 1917 destroyed most of the buildings and made those that survived uninhabitable and the villagers homeless (Figure Slapton 06).  

Figure Slapton 06: as it was in around 1894 from a photograph by Messrs Valentine & Sons. The picture is thought to have been taken at high tide;       Figure Slapton 06: from a photograph taken in 1904 by R H Worth an engineer advising the fishermen. The loss of the shingle beach is obvious.

All that remains of the village are a few houses perched precariously above the eroded shore. Access to the area is now completely restricted except for two families living in the surviving houses. The site can be viewed from a platform which includes information of the history of the village (Figure Slapton 07).  

Figure, Slapton 07: The Hallsands ‘village’ as it is today (August 2002) looking towards Start Point from the ‘viewing platform’.

There is a dedicated web site @ http://www.hallsands.org.uk/index.html hosted by the Cookworthy Museum (see also Barber 2001; Melia 2002; Tanner & Walsh 1984).

Comment: It is not absolutely certain that the extraction caused the loss of the beach as changes to wave patterns and the incidence of storms can also be implicated. Perhaps the beach waxed and waned naturally. However, what does seem to be clear is that with no new sediment to replace the beach from offshore resources, the village was doomed. This example and the evidence that many shingle structures appear to be derived from sources of sediment deposited at the end of the last glaciation (Pye 2001; Orford et al. 2001) make them particularly vulnerable to erosion and loss. New sediment (from the erosion of cliffs) is very restricted at most sites; see for example Porlock Weir, Somerset (Annex 01). This suggests that where there are shingle deposits great care should be taken when interfering with the system in which they occur. The situation at Hallsands might have provided a warning to those concerned with other sites in Start Bay, such as the Hallsands Hotel, Beesands and provide a pointer to the likely outcome of the erosion of Slapton Sands.

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Hallsands Hotel

Just to the north of the lost fishing village of Hallsands, further along the coast lies a small embayment with a shingle shore. Overlooking the beach is a hotel. In the mid 1990s this was a 17 bedroom hotel advertising sub-aqua as well as other recreational facilities (Figure Slapton 08 below)

Figure Slapton 08: The Hallsands hotel in the mid 1990s as advertised in the RSPB ‘Birds’ magazine.

Eroding beaches have caused the cliff, on which it is built, to be attacked by wave action. This resulted in the former footpath running to the left of the hotel becoming impassable and has been diverted to the right of the hotel. At the same time despite extensive ‘protective measures in August 2002 the hotel was boarded up awaiting demolition (Figure Slapton 09 below).

Figure, Slapton 09: The Hallsands hotel in August 2002, boarded up awaiting demolition.

Comment: Hallsands Hotel seems to have suffered from the continuing process of beach erosion followed by cliff erosion, which destroyed Hallsands village nearly 100 years earlier.

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Beesands coastal protection

Beesands, is a small village lying just north of Hallsands, in south Devon. In keeping with the other villages in Start Bay the beach has suffered from erosion. In January 1979 a severe storm threatened the whole community and could have eventually resulted in Beesands going the way of Hallsands some 100 years earlier. However in the late 1980s early 1990s a major investment was made by the Government which reinforced the sea defences in a multi-million £ scheme (Figure Slapton 10 below).

Figure Slapton 10 Beesands: Coastal protection along the village frontage where a concrete sea wall, rip-rap and beach nourishment have all been used to reflect storm waves and prevent flooding of the houses behind.

Comment: It is not certain if this problem represents a knock-on effect from the gravel extraction opposite Hallsands. However it does appear to be a pattern which has and is being replicated around Start Bay including the Hallsands and Hallsands Hotel (see above) and these may provide a pointer to the likely outcome of the erosion of Slapton Sands.

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The future of the road from Torcross to Dartmouth

It appears that the County Council took the decision to move the road following pressure from local people, especially businesses who feared its loss would affect trade. At about the same time the county had money within the financial year to do the work so they did! English Nature agreed to the road being built on this occasion. In order to avoid major conflict, a much better understanding of the processes taking place in Start Bay will be required. The results of this will also need to be disseminated widely within the local community as well as the decision makers at county and national levels.

It is recognised that the decision to move the road was taken in the absence of any long-term strategy. In January 2001 when a storm badly damaged the road about 3,000 tonnes of boulders were placed to help protect it. The fact that they were later removed because of damage to the Site of Special Scientific Interest, suggests recognition of the value of the scientific interest of the system. In order to look at the situation in a wider context and with a longer-term perspective, a scoping study has recently been completed. This reported on the nature of the problem, the impact on the local population, access to the area and the implications for the nature conservation interests. Consultants have suggested hard defences may be needed in the short term, which could be removed at a later date. Incremental movement of the road as the beach recedes is also a consideration.

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Lessons

The problems of coastal erosion at Torcross and along the shingle ridge at Slapton Sands appear to be part of a bay-wide phenomenon. If the current strategy of maintaining the road, albeit in a more landward situation, is maintained then the beach will continue to erode and with it the shingle ridge vegetation (Figure Slapton 11). So long as there is a deficit of shingle material to feed the existing beaches then the long-term sustainability of the system is in doubt. Whilst artificial beach nourishment is an option this is likely to be expensive, especially given the restricted nature of suitable offshore material. Equally the concept of continuing the substantial concrete revetments used to protect Beesands along the coast beyond Torcross to Slapton has significant economic, landscape and wildlife implications.

Figure, Slapton 11: The ‘Shingle ridge squeeze’. As the foreshore erodes and drops the more stable upper beach is squeezed against the road. Repositioning the road to landward only postpones the day when it will become uneconomic to continue to maintain this access.

Comment: It is clear there is a need for a long-term strategy. This strategy must be based on a clear understanding of the evolution of the shoreline of Start Bay and of the way in which human actions have affected its long term stability. The following summary derived from Futurecoast helps set the context.

"There are no significant contemporary sources of material to this coastline. Landsliding in the vicinity of Brixham can occur in response to easterly storms and the removal of toe debris providing a local, although not significant, source of beach material. Toe-trimmed headland slopes fringed by some raised beach deposits are also potential sources in the north, but they are not presently significant. This indicates that the sediments present in Start Bay were derived from the seabed during the Holocene period. This is consistent with the high proportion of flint pebbles (75%), present on the barrier beaches, which have no local source."  

Comment: Given the many interests that are potentially affected it is also clear that any options must consider the whole local area, as well as the Slapton Site of Special Scientific Interest/National Nature Reserve. It will also be important to engage the local community in any deliberations. Because of the past reliance on artificial protective structures they have come to expect that, in the face of erosion and/or flooding, the normal response will be to ‘protect’ life, land and property. Any departure from this approach in respect of the road will require the local authority responsible for the highway, English Nature and the Field Studies Council, which manages the National Nature Reserve behind the shingle bar together with local people and businesses to agree common approaches for considering the issues. This case illustrates the importance of strategic planning in the management of coastal shingle habitat.

In the long-term the increased value of the more natural beach and shingle structure together with the recreational and landscape potential may outweigh the apparent economic losses. Allowing natural processes to reassert themselves may provide the only sustainable option in the long term. The resulting more natural coastal landscape could itself become an attraction in years to come.

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References:

Barber, C., 2001. The Story of Hallsands. Obelisk Publications, Exeter, 32pp. [Provides a contemporary account of what happened, much derived from newspaper articles.]

Barne, J.H., Robson, C.F., Kaznowska, S.S. & Doody, J.P., 1996. Coasts and seas of the United Kingdom. Region 10, South-west England: Seaton to Roseland Peninsula. Peterborough, Joint Nature Conservation Committee.

Melia, S., 2002. Hallsands: a Village Betrayed. Forest Publishing, Newton Abbot, 72pp. [An account which takes a much more detailed look at the political and financial dealings which took place during the period.]

Orford, J.D., Forbes, D.L. & Jennings, S.C., 2001. Origin, development and breakdown of gravel-dominated coastal barriers in Atlantic Canada: future scenarios for North western Europe. In: Ecology & Geomorphology of Coastal Shingle, eds., J.R. Packham, R.E. Randall, R.S.K. Barnes & A. Neal. Westbury Academic & Scientific Publishing, Otley, West Yorkshire, 23-55.

Pye K, 2001. The nature of geomorphology of coastal shingle. In: Ecology & Geomorphology of Coastal Shingle, eds., J.R. Packham, R.E. Randall, R.S.K. Barnes & A. Neal. Westbury Academic & Scientific Publishing, Otley, West Yorkshire, 2-22.

Tanner, K. & Walsh, P., 1984. Hallsands a Pictorial History. Tanner & Walsh, Kingsbridge, Devon, 32pp. [Provides a general overview and summary of most aspects of the case.]

There is also an excellent web site the Slapton Ley NNR site @ http://www.slnnr.org.uk/index.htm which provides a wealth of information about the area it history and natural history.

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