Coastal Solutions

by Adam Hosking

Ed. Note: 

 

Background

Over the last 20 years the UK government has been evolving its approach towards coastal erosion and flood risk management away from the historically ad hoc approach towards the integrated, sustainable model followed today. This model offers a number of potential lessons for the management of these risks here in the US.

The UK has a highly varied coastline, ranging from high cliffs through to areas below sea level protected by beach-dune systems. This diversity gives rise to a broad coastal flooding and erosion risk profile. Recent studies have determined that, under a no action scenario, property loss due to coastal erosion in England and Wales over the next 100 years would amount to around £21 billion at 2005 values. Assets located in coastal flood risk area, have been estimated to be worth about £130 billion, with potential annual average flood damages of around £1.6 billion at 2001 values.

Eastbourne seafront (photo: South East Coastal Group)

Detailed descriptions of the sea conditions around the UK coastline can be found here: http://www.defra.gov.uk/marine/pdf/science/stateofsea/chartprogress-5.pdf

Drivers for Change

During the 1980’s many flood and erosion protection structures in England were coming to the end of their useful life (many had been built as a response to the devastation of the 1953 North Sea floods which killed over 300 people in England and over 1,800 in the Netherlands). With finite budgets to improve or replace these structures, it’s necessary to take a more strategic view of investment in this infrastructure (which is predominantly funded by central government). At the same time there was a growing recognition of the potential ‘knock-on’ impacts of coastal structures on adjacent sections of coast, and in 1989 UK government published its first sea level rise rates for incorporation into coastal engineering designs (a very early climate change adaptation measure).

 

East Anglian cliffs (photo:Defra)

 

 

 

 

 

 

 

The Strategic Approach

The combination of these factors led government to consider their approach to the implementation of coastal risk management projects. The result was the strategic ‘Shoreline Management Planning’ (SMP) process (http://www.defra.gov.uk/environ/fcd/guidance/smp.htm). The first SMPs began in the early 1990’s, with government guidance being published in 1993. These SMPs each consider a large section of coast, normally a sediment (littoral) cell and, over a 50-year time horizon, consider the risk management needs and constraints, integrating all human and natural uses of the coast. This approach facilitates the iterative consideration of alongshore linkages between risk management activities, so the in-combination impacts are identified and managed. It also facilitates the consistent appraisal of the implications of accelerated sea level rise for the evolution and management of coastal risks. Government placed a requirement for an SMP to be in place for a section of coast before protection works would be funded, and further required that the local authorities involved should have formally adopted the SMP, thereby making the (non-statutory) SMPs an important risk management tool.

 

A first set of SMPs were produced for the entire English and Welsh coasts and a review undertaken in 2000. Amongst the key findings were: a lack of consistency in the quality of the science underpinning the plans; a lack of integration with land-use planning; and a tendency for ‘political’ (maintain the status quo) solutions to be adopted.

 

 

To address the scientific aspects, the ‘Futurecoast’ study was commissioned to provide a consistent understanding of the coastal processes operating around the England and Wales coast and projections of future coastal evolution at local and regional scales over a 100-year timeframe. The evolution projections consider with and without coast protection work scenarios, and also take account of sea level rise projections. This basic understanding of the hazards and linkages along the coast provides for an improved scientific basis for future SMPs.

Futurecoast software, sample screen view (Defra)

Following the publication of Futurecoast in 2002, comprehensive ‘procedural guidance’ for the production of SMPs was developed. This addressed the weaknesses identified in the 2000 review and set out the methodology for the production of plans to develop sustainable shoreline management options over a 100-year timescale. To do this the plans consider three time-steps:

• 0-20 years – when existing coast protection practices are likely to be maintained
• 20-50 years – during which transition towards a long-term approach may be initiated
• 50-100+ years – which identifies the long-term ‘sustainable’ approach to risk management for a section of coast.

 

A preferred option is set for each discrete section of coast (divided based on land use and geomorphology) within the SMP frontage, and the spatial and temporal linkages between options are assessed to ensure the overall approach for the SMP frontage is viable. The options are defined as:

• Hold the Line - maintain shoreline in its present position;
• Advance the Line - by building new protection works to push the shore seaward;
• Managed Realignment - by allowing the shoreline to move backwards (or forwards) from its present position, with management to control or limit movement; and,
• No Active Intervention - where there is no investment in engineering works, and risks will be managed through non-structural (e.g. land use planning) approaches.

 

The key features of the strategic framework that has been developed are that it:

• takes a long-term view;
• is forward looking (pro-active) when identifying future problems;
• seeks to develop innovative, but appropriate, solutions;
• has a comprehensive regard to impacts;
• provides for the thorough assessment and reduction of risks;
• requires evidence-based decisions using best science to determine sustainable approaches;
• involves stakeholders and decision-makers throughout plan formulation;
• shows balanced decision making when determining the chosen options; and,
• allows for the periodic review and updating of management policies in the light of new knowledge.
  

  United Kingdom coastline, satellite view (NOAA)

   

   

   

   

   

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  SMP Boundaries (Defra)

  See an example SMP Review for Zone 4c, South Foreland to Beachy Head, England, including the maps, plan recommendations and glossary of terms, and action plan for implementation.

   

   

   

   

   

 

 

 

 

 

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