Coastal erosion in Ireland – engineering solutions for future management
20 June 2017
Downpatrick Head, Co Mayo
In part one of this article, Dr Jimmy Murphy outlined Ireland’s history of engagement with the coast in relation to erosion and examined the efficacy of previous attempts to address the problem.
The approach adopted by the Office of Public Works (OPW) is practical and, in general, is in line with local authority opinions – the councils say that they are aware of the locations at most risk to coastal erosion and those specific locations have been prioritised for coastal protection works.
What this means is that for the medium term at least, Ireland, unlike most European countries, will move forward with a policy/framework for dealing with erosion rather than a strategy for managing our coastline. To develop such a coastal erosion strategy, a detailed study of our whole coastline would be required and in itself this could be an undertaking as significant and as costly as the successful CFRAMs (Catchment Flood Risk Assessment and Management) programme.
So, given that Ireland is in general going to carry on as before, the question arises as to whether we can start to take actions now that will help current projects and facilitate future actions.
The MaREI Centre (Centre for Marine and Renewable Energy) surveyed local authorities about what they thought Ireland could do better in terms of managing the protection of our coastline and the following suggestions were offered:
- Policy development in relation how we deal with coastal erosion. This can relate to what strategy that should be adopted (do nothing, managed retreat, etc) to the selection of particular coastal protection techniques (revetment or nourishment). Particular issues arise in relation to private property at risk of erosion and how these should be managed;
- Protection strategies and study requirements related to areas where there are environmental designations (Special Areas of Conservation, Special Protection Areas, etc);
- Restriction of development on eroding coastlines (at least 100m);
- Provision of higher funding levels;
- Creation of a unified single body responsible for the coastline;
- Develop and implement a management policy including funding allocation and all consents to streamline the existing system.
Elements of a national strategy study
The above points touch on issues that are very relevant and form elements of a national strategy study. In addition, I would propose the following:
- Work towards a more consistent national approach towards assessing erosion risk. Currently, each local authority develops its own methodology for the identification of sites to be included in submissions to the OPW for funding. It would be a useful initiative if local authorities established a formal collaborative mechanism to enable better co-operation, interaction and standardisation of methodologies.
This may help to move away from competition between local authorities for funding with the production, at a national level rather than a county level, of a list of the most critical sites requiring protection. This could focus more attention on the issue of coastal erosion and may help release extra funding for protection works.
- The previous action should identify locations of national importance that are vulnerable, but may not require immediate action (could have had recent repair work). For these locations, a monitoring programme, involving topographic and bathymetric surveys and wave/tide/current measurements, should be implemented.
Annual surveys would be relatively low cost, some could be undertaken by the local authority but would provide the data essential to the design of future works.
Photographic surveys, which are currently undertaken by many local authorities, are useful but, for engineering design, quantitative information is required. In addition, post-construction monitoring should also form part of any coastal-protection project to understand the impact of the works on the coastal system. Monitoring programmes could be specified at a national level, such that there would be consistency in the data collected, and the OPW could act as a central repository.
- Is the 1963 Coast Protection Act still the most appropriate legislation for dealing with the likely higher engagement that will be required in relation to coastal erosion? In 1997, the Brady Shipman Martin Report stated that “the legislative framework are out of date and inadequate to the task in hand” and it was “unwieldy and insufficient in scope”. It is likely that it is the dearth of coastal protection works that enables this act to endure 20 years later after these comments. However, it would be worth examining the robustness of this act to the challenges ahead.
- In other countries, strategy studies have shown that managed retreat or ‘do nothing’ options are the only cost-effective solutions to coastal erosion. Such options are often not popular and maybe part of the reason for not prioritising sites at a national level in Ireland. However, my view is that we need to give clarity to the property owners as to what will or will not be done and what support can be provided at a national level.
Currently, both authorised and unauthorised privately funded coastal protection works are being put in place and in some cases without an understanding of the overall beach dynamics. Property owners believe that they have no other choice and generally feel isolated from decision-making authorities. Therefore, better guidance and support should be given in these situations and, if the property has to be lost, then arrangements that have worked in the UK, whereby residents are offered compensation and planning at a nearby location, should be investigated.
- Examine more innovative options for managing and protecting the coastline. Coastal defences are tending to be higher and bigger to take account of future uncertainty and this can have a negative local impact. The Dollymount promenade flood defence wall is a case in point, where it was described locally as the ‘Berlin Wall’ and attributed to blocking views of Dublin Bay. There is also opposition to the perceived blanket armouring of our coastline and the resulting loss of dry beach area.
It is likely that opposition to proposed solutions will become more common if engineers continue the traditional route in relation to coastal-protection solutions. There are alternative solutions, which require research and development but could provide viable alternatives to traditional approaches. Of interest to MaREI are active and demountable systems that can deal with the severe events and not be a dominant feature on the coastline.
- There is a need for more engineers with expertise in coastal engineering. Many engineers learn on the job, but a higher level of training – especially through more advanced undergraduate courses as well as Masters and PhD degree courses – is needed to achieve the critical mass required to deal with future challenges.
- Better education and outreach to stakeholders such that they can be more informed of the practical choices associated in relation to costal erosio.n
This article has shown that Ireland up to now has been moderately active in terms of managing coastal erosion. It is not currently considered to be a major issue, but may become so in the next decade.
It is understood that large budgets are not available for studies, protection works and research but what is proposed are a number of measures that can be incorporated within the present framework that will help us in dealing with future challenges.
Dr Jimmy Murphy has over 20 years’ experience working on consultancy and research projects related to coastal engineering and marine renewable energy. This work primarily involves examining the impact of engineering works on the physical marine environment through the use of field measurements, numerical modelling and physical modelling techniques. He has undertaken projects at many locations around Ireland in relation to coastal erosion and the construction of new piers/harbours and marinas. He also lectures in the School of Engineering at UCC on the subjects of environmental hydrodynamics and harbour and coastal engineering. He has a number of publications in the areas of coastal engineering and renewable energy.http://www.engineersjournal.ie/2017/06/20/coastal-erosion-ireland-engineering-solutions-future-management-part-2/http://www.engineersjournal.ie/wp-content/uploads/2017/06/coastal-erosion-1024x644.jpghttp://www.engineersjournal.ie/wp-content/uploads/2017/06/coastal-erosion-300x300.jpgCivillocal authorities,marine,OPW,UCC