Shoreline Management Plans (SMPs)

What is an SMP?

A Shoreline Management Plan is a high level, non-statutory policy documents that provides a large-scale assessment of the risks associated with coastal processes and the consequences of climate change. Coastal processes include tidal patterns, wave height, wave direction and the movement of beach and seabed sediments.  An overview of how they have evolved and are structured can be found here.

The Four Options

SMPs look to provide assessments in short (0-20 years), medium (20-50 years) and long term (50-100 years) planning, and provide one of four options for each section of coast;

  • Hold the Line - maintaining the existing line of a defence
  • Managed Realignment - allowing the shoreline to move in a controlled way, with management to control or limit the resulting effects.
  • No Active Intervention - essentially means ‘do nothing’.
  • Advance the Line - building of new defences seaward of existing defences

The Environment Agency's Role

The body responsible for implementing policies for flood defence is the Environment Agency.  In the majority of places, and Sussex is no exception, the policy is ‘hold the line’.  However, there is no guarantee that the line will be held. 

  • The Environment Agency has permissive powers (but not a duty) to carry out flood and coastal risk management work.
  • Even if an SMP says ‘hold the line’ funding still needs to be secured to make it happen.  Thus the policy is described as an ‘aspiration’ not an assurance. 
  • In some instances, ‘hold the line’ may carry a condition that defences will only be built or maintained if some or all of their cost is paid for by those who benefit from them.
  • Environment Agency funding comes from Defra, and is not guaranteed.  Indeed in November 2015, Defra’s budget was cut by 30%, the largest of any government department.  Consequently it is no surprise that the Agency cannot commit to precisely what can be done each year, particularly with sea defences, where levels of expenditure are directly related to the weather experienced each winter.

Pevensey Bay's SMP

The first SMP for the stretch South Foreland to Beachy Head was produced in 1996. As they must reflect changes in the natural world, SMPs require regular review. For South Foreland to Beachy Head a first draft revision was produced in January 2005, with a final version in April 2006.  All documents associated with the current SMP can be found here. Each document provides a management plan for the next 100 years and the policies required for it to be implemented. Below is a summary of the plan for the area covered by Pevensey Coastal Defence. The proposed management for the whole frontage is to "hold the line".

Sovereign Harbour - 4c28


A major marina development extending to the beach edge, within a flood risk area. The plan is to continue protecting the extensive developments from flooding and erosion. This approach will ensure the continued operation of the harbour, marina, associated commercial and recreational operations and the large number of residential developments. This unit also forms part of the flood risk area linked to the adjacent frontages, so protection to these areas will also be provided. An impact of protecting this development is that the ‘Crumbles’ shingle, upon which the development is built, will be prevented from returning to the shoreline system. This shingle supply could benefit beaches to the east, if it were allowed to erode. Without this input, there will be narrowing of the beach due to rising sea levels, such that it is likely that there may be little or no beach here in 100 years time and linear hard defence structures being required.

Preferred policies to implement Plan:

From present day: The present day policy for Sovereign Harbour is to continue to hold the line by maintaining and improving the existing defences to protect the significant assets from flooding and coastal erosion. With rates of sediment feed and transportation along this frontage being low, very little change in coastal processes are likely to occur within this epoch. In maintaining the defences the shoreline is held seaward of its natural alignment, providing a degree of protection to the Pevensey frontage. The shingle source at the Crumbles although substantial is not sufficient to truly benefit frontages downdrift in the long term and once released, would significantly increase the pressure on this frontage.

Medium-term: The medium term policy for Sovereign Harbour is to continue protecting the marina complex and hold the line, by maintaining and upgrading, the existing seawall, harbour arms and groyned shingle beach, to provide adequate protection against sea level rise.

Long-term: The long-term plan for Sovereign Harbour is to continue protecting the substantial built assets by holding the shoreline in its current position. The character of Sovereign Harbour is unlikely to change too significantly, as this section of the coast is already heavily defended however retaining a beach in front of the significant defence structures will become increasingly difficult with sea level rise. Thus changes in management approach may be required, with a possible loss of the amenity beach. This recommendation is deemed sustainable, as although a 'store' of shingle is being held up, this material provides protection to this frontage and its substantial assets as well as the immediate frontage updrift.

Hooe to Pevensey Levels - 4c27


Low lying frontage with residential developments backing much of the coast and areas of international environmental importance within the flood risk area. The plan here is to protect the numerous properties behind the existing beach and important infrastructure such as the railway line and A259 road. The land backing the coast and throughout the backing flood risk area, is very low, such that any inundation could affect a very large area. As such the benefits of continuing to provide flood protection include protecting large areas of internationally important freshwater habitats from tidal inundation, large areas of agricultural land, numerous important heritage sites and properties throughout the Levels. The potential flood area also extends into Eastbourne's urban area so flooding risks to this are also reduced. This section of coast is already heavily managed, based on a relict sediment source (i.e. there is no natural contemporary source for this shingle) and in the future, due to sea level rise, it is likely that hard defences will be required to provide an adequate standard of protection in the long term. This would result in a narrowing of the beach such that those properties currently built upon the crest of the beach may be lost.

Preferred policies to implement Plan:

From present day: The present day policy for Hooe and Pevensey Levels is to hold the line and continue protecting the low lying hinterland and shoreline settlements by maintaining the seawall, groynes and shingle recycling. Presently the shoreline is slightly retreating, thus without ongoing beach recharge and maintenance of these defence structures all foreshore sediments would be lost very quickly. This situation will be exacerbated in the future; with sea level rise it will become increasingly probable that hard defences will be required to provide the adequate standard of protection in the long term.

Medium-term: The medium term policy for Hooe and Pevensey Levels is to continue to hold the line, although this will become increasingly difficult with sea level rise and a relict sediment supply. To accomplish this, beach management measures may need to be increased during this epoch.

Long-term: The long-term policy for Hooe and Pevensey Levels is to continue protecting the assets through a hold the line policy which may require substantial engineering structures to be constructed, as it may become prohibitively difficult to maintain an adequate standard of protect with the current beach management approaches alone. With numerous economic, environmental and heritage assets at risk and the need to protect them, the character of this frontage will change, from one that offers a beach and associated amenities to one of extensive hard defences with little or no beach, due to sea level rise and a lack of contemporary sediment entering the system.

The Future

The Policy Unit overview for “Hooe and Pevensey Levels" also recognises that 'hold the line' cannot continue indefinitely;
“It must be recognised that, in the very long term, continuing to defend such long stretches of shoreline with increasing exposure may become technically and economically unsustainable and consideration to relocate, or mitigate, for loss of assets should be considered in the future. Even where this point is considered to fall outside the SMP timescale (i.e. beyond 100 years), it is still very important to recognise that maintaining current alignments will not be possible indefinitely.”

“The consequences of the long-term management plan for this coast cannot be understated. However, the inevitability of necessary change to past policies needs to be recognised. Continued defence, as in the past, is unsustainable in the long-term for particular frontages and it is unrealistic to present proposed policies that indicate continued defence of an area where this is unlikely to be sustainable or economically justifiable.”

Pevensey Coastal Defence Ltd, Westminster House, Crompton Way, Segensworth West, Fareham, Hampshire, PO15 5SS
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