Coastal erosion

What is coastal erosion and when is it a problem?
What can be done?
Key concepts
Indicators and monitoring
Potential interventions
Setback lines
Use of models
EU policies and Directives
The way forward
How to do it?
Systematic approach
Decision loop
Relevant Web links


4. What intervention is applicable ?
Make your objectives
Achievable - Are the objectives you set, achievable and attainable?
Realistic – Can you realistically achieve the objectives with the resources you have?
Time – When do you want to achieve the set objectives?

Once an erosion problem has been specified (step 1) and quantified in terms of one or more indicators (step 2), and once a benchmarking procedure has been established (step 3), a decision must be made on the most applicable intervention method.

  1. What are the objectives ?
  2. What is technically feasible and ecologically optimal ?
  3. What is financially feasible ?
  4. Who is accountable ?


1. Objectives

Designing an intervention procedure, it is important to memorize the context of the problem and the objectives that must be achieved (step 1, step 2, step 3 ). All this should be reflected in the nature of the design, it’s geographical extend and temporal dimension (life cycle).


2. Technically feasible and ecologically optimal

Understanding the dynamic nature of the coastal margin is a key factor in managing coastal erosion. EUROSION recognises the sustainable development of coastal zones and the conservation of dynamic habitats, especially on the remaining undeveloped coast, as important long term goals for European coastal zones. This requires a respect for, and in many cases restoration of, the natural functioning of the coastal system and hence its natural resilience to erosion. Key concepts like resilience, coastal sediment cells, favourable sediment status and strategic sediment reservoirs play an important role.

A technically feasible and ecologically optimal intervention scheme, according to EUROSION should be found in restoration of the sediment balance and providing space for coastal processes.

Buffer zone
Allowing space for natural dynamics may be accomplished by delimiting and maintaining a buffer zone. The landward boundary of such zone, where building restrictions and prohibitions are applied, generally is defined as a set back line. A set back line basically is a trade off between coastal development and prevention of an unacceptable risk due to coastal erosion.
An overview of the defintion of set back lines in Europe is provided by CONSCIENCE report D12.

Sediment nourishments
For restoration of the sediment balance and maintainance of a buffer zone, an obvious option is sediment nourishment. Coastal erosion including sea level rise effects can be mitigated by shoreface, beach and/or dune nourishments with sediments of comparable size or with slightly coarser sediments.
Pilot sites Holland, Coast Brava and Hel Peninsula represent examples of sand nourishments, pilot site Pevensey is an example of gravel nourishment. An overview of potential interventions and practical experiences is presented by CONSCIENCE report 13a.

Hard structures
In cases where local availability of sediments is lacking, or in urban areas where space for natural dynamics of coastal processes, is limited, hard structures may be applied to combat erosion. Coastal structures such as groynes, detached breakwaters and artificial reefs are built to significantly reduce coastal beach erosion and to maintain a minimum beach width for recreation or to protect beach fills.
Pilot site Coast Brava and Romania represent examples of the effects and effectiveness of hard structures. An overview and evaluation of different potential interventions and practical experiences is presented by CONSCIENCE report 13a.


3. Financially feasible

It is difficult to make generalised cost estimates of potential interventions. Cost largely depend on local conditions, such as the design of the measure, the availability and type of material used, local prices for labour and material etc. A cost-benefit assessment may shed light in this matter.
Some rough cost estimates based on practical experience, are presented by CONSCIENCE report 13a.


4. Who is accountable ?

Considering “Accountable coastal erosion management”, EUROSION indicates a.o. the importance of (-) clear responsibilities at various levels of administration and (-) an appropriate budget for both investments and maintenance as well as for a financial mechanism to locally accommodate erosion or its impacts.
As illustrated for example by the various CONSCIENCE pilot sites and by CONSCIENCE report D8, accountability differs largely across Europe. A clear analysis of these aspects at a particular site, is necessary to attain an implementable strategy.


A specific targeted research project under the
EU’s 6th Framework Programme for Research (FP6)