In this section you will learn about approaches that can be used to adapt to the identified impacts of climate change by the 2050s on coastal evolution.

These approaches are intended to enable society and appropriate organisations to build resilience and limit the negative impacts of the changing climate. This section primarily relates to coastal erosion, but also considers accretion and other changes in features (coastal evolution) where appropriate.

 

Adaptation
Fundamental in adaptation to the risks across the region’s coastline from erosion associated with climate change is a decision about whether or not to intervene to stop or reduce the recession of the shoreline.

A Shoreline Management Plan is the non-statutory document which sets the policy for each length of coast around England and Wales taking into account environmental, social and economic factors over a 100 year time period.  Policy options include ‘hold the existing line of defence’, ‘no active intervention’, ‘advance the existing line of defence’ and ‘managed realignment’.

In areas where there are extensive developments, or important economic assets, it will usually be likely that the most cost-effective solution is to provide coastal defences (and then subsequently maintain them to suitable standards), rather than relocate the assets in the short to medium term.  On coastlines subject to rapid erosion or increasing frequency of flood events it may become necessary to plan for the relocation of  assets in the longer term where continued maintenance of coastal defences  is having an adverse environmental impact on other coastlines (for instance through preventing the transfer of sediment from eroding coastlines or squeezing coastal and estuarine habitats).

Where small or isolated assets are vulnerable, it can often be more cost-effective, and more sustainable, to relocate the assets than it would be to provide coastal defences.  This adaptation approach is advocated in East Riding of Yorkshire Council’s Integrated Coastal Zone Management Plan: Towards a Sustainable Coast (ERYC, 2002) and is particularly relevant where assets can be moved without loss of their overall function (i.e. landward relocation of mobile homes, re-planning the layout of golf courses, and realignment of sections of coastal footpath).  Where it is not possible to do this, then local management that is sensitive to the nature of the region’s coastline is possible.  Where this approach is selected, innovative options, such as sediment recycling or construction of local ‘hard points’ to modify coastal configuration, will increasingly be used in preference to traditional hard engineering approaches in some suitable locations. 

Along frontages where coastal defences are already in existence, their ongoing inspection and maintenance is critical.  The more recently constructed defences will have been designed taking into consideration the effects of sea level rise in accordance with guidance from central government (Defra), but older defences are unlikely to have considered such matters and, due to their age, will also require significant upgrading, replacement or removal/relocation before the 2050s.  Pro-active identification of the need for, or desirability of, this will be determined through the ongoing processes of Shoreline Management Plans and Coastal Defence Strategy Plans, which are subject to periodic review and updating in light of the latest climate change science and the nature and scale of the erosion risks posed.

In some coastal and especially some estuarine frontages, it will not be sustainable or cost-effective to maintain flood defences and in some locations realignment or removal of flood defences has already been undertaken (e.g. at Paul Holme Strays, Alkborough and Chowder Ness) and is actively being considered in other areas.  This not only has the benefit, in appropriate situations, to enable inter-tidal habitat to be created to offset the anticipated losses due to either new developments or the impacts of climate change elsewhere (i.e. where flood defences are being maintained into the future, leading to coastal squeeze) but also can prove effective in relieving pressure elsewhere within the estuary system.  Considerable work has recently been undertaken on the Humber Estuary investigating the preferred long-term (50-100 years) management policies in light of climate change and other key factors.  It is not the intention to repeat this extensive information here, but rather to highlight the importance of this work and of ensuring that its findings are periodically reviewed in light of ongoing monitoring and changing national guidance on projected climate changes.

 

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| North Yorkshire | Humber |

 

The Shoreline Management Plan has identified an adaptation policy to defend the road at Cowbar Cottages over the next 50 years and due to this, the threat of thinning and ultimate breaching of Cowbar Nab will be reduced.  Ongoing monitoring will be needed to identify potential outflanking at the ends of defended sections, but local adaptation works in the form of small-scale armouring could be used to remedy any such situations.

Adaptation in some areas will be to accept ongoing erosion and landslips and to deliberately not intervene in arresting or slowing down this process.  Due to the resultant ongoing erosion and landslips, the frequency and magnitude of which will be exacerbated by climate change, some sections of the Cleveland Way long-distance footpath will require relocation away from the cliff edge.  On a similar theme, the coast road at Sandsend Bay will need relocation in the longer-term due to cliff recession.

If it is to be retained, the existing beach at Whitby Sands will need to be enhanced at some point over the next 50 years through the replacement of timber groynes to help retain material drifting along the shore.  This would help build beach levels that would contribute to reducing the overtopping of the existing defences.

Due to the importance of the Whitby Harbour piers, both to the harbour operations and to retaining the beach along Whitby Sands, a major capital investment is required to upgrade the structures to ensure they do not breach under the increased future wave and tide loadings.  In designing an appropriate scheme an opportunity is also available to enhance the overtopping performance of the structures in the light of rising sea levels.  This could involve raising crest levels or placing rock at the toe of the seaward face.  If this is not undertaken then adaptation of the use of the piers by the public is required, with more formalised closure of access to the piers during storms with, possibly, a pier watchman or an automatic gate linked to the Environment Agency’s Flood Warning System.

Rock armouring at the toe of concrete seawall defences along the Scarborough frontages will assist in breaking up wave energy and hence help reduce overtopping potential.  It will also assist in protecting the seawall toe during periods when foreshore lowering is observed.

Within Cornelian Bay and Cayton Bay, the recent Shoreline Management Plan 2 (SMP2) has identified that investment in a major scheme(s) to provide toe protection or improved drainage to the cliffs is not warranted given the value of the assets at risk.  Instead, policies of ‘no active intervention’ are proposed.  With projected increases in rainfall during winter months and rising sea levels over the next 50 years, further investigations of the likely mechanisms and timescales of cliff instability are ongoing.  Monitoring and evacuation plans are recommended by the SMP2 to be implemented to ensure public safety in the event of any slippage which compromises properties along Cayton Cliff.  Furthermore, advice to owners of the Caravan Parks atop Gristhorpe Cliffs regarding longer-term relocation of sections of their sites is required and part of the Cleveland Way long-distance footpath will need to be realigned landwards.

The SMP2 identifies that in the longer-term, providing defences to areas of landslips at Flat Cliff, Hunmanby Gap and Reighton Gap is considered unsustainable for two main reasons, despite the risk to residential communities and the large holiday parks.  Firstly, the economic benefits of providing sufficiently robust engineering solutions to the risks that are faced only marginally exceeds the economic cost of doing so and therefore the ‘value to the nation’ is marginal.  Secondly, defences introduced would accelerate rates of erosion elsewhere along the frontage.  Due to this, the recommended policy is one of ‘no active intervention’ (i.e. no defences to be constructed).  However, it is also recognised that immediate discussions are needed in terms of adaptation approaches to: (1) reduce the threat to people, property, infrastructure and businesses from landslips and erosion (e.g. a monitoring programme linked to early warning systems and pre-defined emergency response plans and business continuity plans); (2) address the issue of loss of access to properties of Flat Cliff over the next few years; (3) address the issue of loss of properties themselves and safe management of access between the cliff top and the beach over the next 5 to 20 years; and (4) assess the impact on, and future operations of, the holiday park over the mid term (20+ years).

Further detail on the adaptation responses that are proposed by coastal managers within North Yorkshire over the next (nominally) 20, 50 and 100 years are presented in the River Tyne to Flamborough Head Shoreline Management Plan 2, which can be obtained from the following website: ‘www.northeastsmp2.org.uk’.

 

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The adaptation approach to erosion along the open coast is, in general, presently to allow the natural development of the coast in so far as is practicable, meaning that erosion will be allowed to continue along presently undefended sections.  This avoids the construction of unsustainable defence schemes that may also have adverse effects on downdrift frontages.  At a more specific scale, the appropriate adaptation responses looking ahead over the next 20, 50 and 100 years and taking into account climate change effects are presently being considered in the (ongoing) Flamborough Head to Gilbraltar Point Shoreline Management Plan 2.  This document will need to address some critical challenges as it is developed throughout 2009. 

For example, maintaining the existing line of defences at existing hard points such as Hornsea and Withernsea whilst allowing the rural areas in between to erode will, over time, create bays which may have detrimental effects both locally and on other coastlines.  Effects include undermining and outflanking of the retained coastal defence structures including loss of beaches at the coastal towns.  Over time the bays will become deeper and increasingly trap sediment thus reducing the sediment supply to Spurn Peninsula, the Humber Estuary and the further afield Lincolnshire beaches.  However this is likely to be the most acceptable solution for local communities and politicians in the short to medium term at least.

An alternative adaptation model for the Holderness coast would be to allow the coast to erode according to its geological character, maintaining sediment supplies to adjacent coastlines in line with sea level rise and increased storminess. However this would involve the abandonment or removal of coastal defences and relocation of coastal towns for which there is currently no technical or financial mechanism.

At Easington Gas Terminal, the existing coastal defence will require increased maintenance in future years due to the increasing exposure conditions.  This may involve the need for displaced rocks to be relocated in the revetment armouring and local works at either end of the defended section of coast to limit risk of outflanking.  However, in the longer term critical decisions need to be made at Easington about how long the site can remain operational given both the diminishing stocks of North Sea gas and the increased erosion pressure caused by climate change.  Whilst defending the coast can be continued in the short and medium term, the longer term prognosis is likely to be for decommissioning of the terminal.  The timing of this should be planned within a broader national framework of energy generation and taking into account the ongoing importance of the facility in landing gas via the interconnector from the Norwegian sector gas fields.

Within the Humber Estuary, management of inter-tidal erosion is linked to management of flood risk.  The Humber Flood Risk Management Strategy (Environment Agency, 2008) identifies lengths of foreshore where it may be difficult to justify future defence improvements.  It may be many years before final decisions are taken on whether or not to maintain individual lengths, but if any of the defences were ultimately abandoned, that would eventually result in new habitats being created that would counter the losses caused elsewhere by coastal squeeze

Further detail on the adaptation responses that are proposed along the open coastline by coastal managers within the Humber sub-region over the next (nominally) 20, 50 and 100 years will be presented in the Flamborough Head to Gilbraltar Point Shoreline Management Plan 2, which will be obtainable from the following website: ‘www.hecag-smp2.co.uk’.  This document is expected to be completed by the end of 2009.

In addition, further detail on the adaptation responses that are proposed along the estuarine shores by flood risk managers within the Humber sub-region over future decades is presented in the Humber Flood Risk Management Strategy (2008) which is available from the Environment Agency.

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