Groynes in coastal engineering
A report detailing a consistent approach to the design and management of both rock and timber groynes.
Documents
The outputs of this project were published by CIRIA (Construction Industry Research and Information Association) in May 2020. To access the report visit the CIRIA project webpage
Project summary
This project has developed a new guide to designing, constructing, monitoring, maintaining and decommissioning of narrow footprint groynes. The guide builds on the content of the CIRIA 1990 groynes manual and complements two other CIRIA guides: the Beach Management Manual and the Rock Manual. It focuses on good practice approaches to maintenance and the performance of sustainable materials.
Background
A groyne is a long narrow structure built out into the sea from the beach to limit the movement and loss of beach material (sand and shingle). Groynes form a significant part of coastal protection around the UK coast. Groyned beaches protect around 50,000 properties that lie within 100 m of average high tides. Investment costs to build, maintain and decommission them are high. For example, major repairs at Dawlish Warren to just 3 of the existing 17 groynes cost in excess of £380,000.
Method
The guide has been written by leading experts in their field, including practitioners to ensure it is accessible to everyone, from the coastal manager to those designing a groyne field and those carrying out monitoring and maintenance. The project has benefitted from wide collaboration, from an online survey and scoping workshop at the outset through to a delivery team that represents the range of roles and interests in groyne management.
Results
The guide covers practical issues on topics such as site investigation, design details, materials, fixings, including looking at factors such as biological, chemical and mechanical deterioration. It includes photos, drawings and case studies to help users.
The guide presents innovations and examples of good practice. For example, an innovative way of fixing planks to piles of groynes was developed at Dawlish Warren offering a cost saving of £250,000.
Next steps
The new guide is freely available via CIRIA’s website. The webinar launching the guide can be accessed here.
Project information
Project manager: Sue Manson, Flood and Coastal Risk Management Research, Environment Agency.
Last updated 29 March 2022 + show all updates
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A Welsh translation of the project summary has been added to the project details section.
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The project summary has been published and project is complete. Links to the report published by CIRIA have been added to the documents section.
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First published.