Managed Realignment : A Viable Long-Term Coastal Management Strategy?

Managed realignment has been a preferred coastal management strategy in England in the 21st century and has also been increasingly implemented elsewhere. Climate change and environmental and financial concerns have led to a shift from the traditional 'hold-the-line' approach of coastal protection towards more flexible soft engineering options. Managed realignment is a relatively new soft engineering alternative aiming to provide sustainable flood risk management with added environmental and socio-economic benefits by creating space for coastal habitats to develop more dynamically. The natural adaptive capacity of coastal habitats and the ecosystem services they provide underpin the sustainability of managed realignment. However, many definitions of managed realignment exist and the understanding of what the term actually represents in practice has evolved through time and varies regionally.

This book clarifies the definitions and terminology used in the literature and proposes that managed realignment is used as a general term that encompasses the many different methods of implementation worldwide, including: removal, breach and realignment of defences; controlled tidal restoration (which includes regulated tidal exchange and controlled reduced tide); and managed retreat. These methods of implementation are explained and illustrated with examples from around the world. In addition to a general overview of emerging policies and current practices, specific chapters discuss approaches adopted in different locations, including the Netherlands, the UK and Maui (USA). The UK experience is presented from the perspectives of three sectors: the National Trust (a charity organisation that owns 10% of the coastline of England and Wales), the Environment Agency (the organisation responsible for implementing government policy concerning flood and erosion risk) and a private consultant involved in the planning, design and delivery of managed realignment projects. Taking a wider perspective to consider the range of implementation methods, the viability of managed realignment as a long-term coastal management strategy is discussed.

Recent national and regional strategies worldwide give managed realignment an increasing role in climate change and flood risk management. Gaining stakeholders and public support is fundamental for the success of emerging coastal management strategies. However, public perception and stakeholders engagement are often cited as a factor limiting the wider uptake of managed realignment. Results from a recent survey are used to benchmark the current thinking about the potential, the performance and the limitations of managed realignment in the UK and elsewhere. Current opinions about managed realignment are often not clearly defined, partly due to many projects being relatively recent. There is a general perception of great potential to provide sustainable flood risk management with added environmental benefits. However, the views of stakeholders are considerably more negative and notably contrast with the views of practitioners and researchers. The only clear and dominant agreement across all groups of respondents is that better understanding about the long-term evolution of sites is needed.

Auteur

Dr Luciana Esteves's research and teaching interests are related to environmental change in coastal areas driven by natural and human-induced process and the implications to coastal management., especially related to flood and erosion risk management. She has conducted research in Brazil, the USA and in the UK. She has worked in research projects funded by the EU, NERC and SW Regional Development Agency addressing the impacts of storms on coastal morphology, coastal flooding by extreme events and environmental impacts of marine renewable energy. Currently she is a Senior Lecturer in Physical Geography at Bournemouth University (UK) and a fellow of the Royal Geographical Society.

Contributors:

Thorne Abbott, Coastal Planners, Coastal Resource Planner, Hawaii, USA, Thorneabbott@yahoo.com

Thorne Abbott is currently a consultant specialised in assisting oceanfront landowners in addressing erosion crisis and shoreline change in Hawaii. He has over 20 years of experience in natural resources management in the public and private sectors in continental USA and in the territories in the Pacific Ocean.

Phil Dyke, The National Trust, Coast and Marine National Specialist, UK, Phil.Dyke@nationaltrust.org.uk

Phil Dyke has 30 years of experience working for the National Trust on coastal and marine issues. In his current position since 2007, he supports the National Trust in England, Wales and Northern Ireland to implement sustainable coastal and marine management approaches. In addition to his role at the National Trust, Phil teaches coastal and marine management and he is the Chair of the EUROPARC Atlantic Isles Coast and Marine Working Group, which seeks to promote integrated management approaches in protected areas.

Tony Flux, The National Trust, South West Region Coast and Marine Adviser, UK, tony.flux@nationaltrust.org.uk

Tony Flux has extensiveexperience in issues concerning coastal management in South West England. As a Coastal Adviser for the National Trust since 2007, he supports projects along the Dorset and East Devon coasts. Previously, Tony worked for the Dorset Coast Forum and the Dorset Areas of Outstanding Natural Beauty team.

Jan P. M. Mulder, Deltares and University of Twente, Assistant Professor, Netherlands, jan.mulder@deltares.nl

Jan Mulder has over 25 years of experience in researching topics related to coastal morphology and management. He has worked at TNO, Dutch Ministry of Infrastructure & Environment (Rijkswaterstaat) and, since 2008, at Deltares. Jan is also part-time assistant professor at Twente University. His expertise includes translation of research into policy and the integration of field observations and empirical and numerical modelling concerning physical and ecological disciplines.

Nigel Pontee, CH2M HILL, Global Technology Leader Coastal Planning & Engineering, UK, Nigel.Pontee@ch2m.com

Nigel Pontee has 20 years of experience in consultancy work concerning coastal geomorphology and management, during which he has contributed to over 190 estuary projects, including the appraisal of over 150 habitat restoration sites and the design of managed realignment schemes in the UK. He has authored over 200 consultancy reports and over 75 publications on coastal and estuarine shoreline management aspects, including managed realignment and habitat creation design.

Joost Stronkhorst, Deltares, Senior Coastal Policy Advisor, Netherlands, joost.stronkhorst@deltares.nl

Joost Stronkhorst has more than 30 years of experience in the development of water and sediment management in the Netherlands and multidisciplinary coastal research. He has worked for the Dutch Ministry of Infrastructure & Environment (Rijkswaterstaat) where he was involved in the Delta works andmarine pollution control.

Karen Thomas, The Environment Agency, Senior Coastal Advisor (Eastern Area), UK Karen.thomas@environment-agency.gov.uk

Karen Thomas is a technical expert in flood risk management with 20 years of experience in management of coastal issues at the national and local levels. Karen has led the Essex and South Suffolk Shoreline Management Plan and works on managed realignment projects since joining the Environment Agency in 1999. She works with communities and stakeholders to encourage greater interest in managing the coast in a more sustainable manner.

Contenu

1. Introduction.- 2. What is managed realignment?.- 3. Methods of implementation.- 4. Examples of relevant strategies and policies.- 5. Considerations on managed realignment in the Netherlands.- 6. The National Trust Approach to Coastal Change and Adaptive Management.- 7. Managed Retreat in Maui, Hawaii.- 8. Manage…