Developing practical guidance on flood defence embankments - HR Wallingford is leading the UK’s technical input into a new international handbook on flood defence embankments (also known as levees).

Over the last decade, storms such as Hurricane Katrina in New Orleans and Tempête Xynthia in France made landfall with the accompanying surge in water levels that severely tested the local flood defence systems. In some cases, critical defences failed leading to a tragic loss of life and the devastation of large areas of land. The poor performance of coastal and river flood defence embankments was a critical factor in the scale of the tragedies in New Orleans and France, just as it had been in the North Sea floods of 1953, which badly affected the Netherlands and the UK.

Flood embankments (or 'Levees') are used throughout the world to provide a vital line of defence against flooding. In England and Wales, for example, the Environment Agency is responsible for 7500 km of flood embankments (Defra, 2007).

The tragic events in New Orleans in 2005 demonstrated the critical nature of such structures and the catastrophic consequences of their failure. The need for a comprehensive approach to management of flood defences is vital to ensure that their performance in maintained over the long term.

There is considerable experience worldwide, and it makes good sense to draw together the different knowledge and skills in the assessment, design, construction and maintenance of levees across various countries. Practitioners agree that there will be significant benefits in drawing together and sharing ‘good practice’, especially with the increasing challenges face ed by those involved in flood management.

HR Wallingford is working with partners from Germany, France, Ireland, the Netherlands, the UK to make this vision a reality. A single, comprehensive handbook will bring together international practice and knowledge and will make the dissemination and wide use of consistent standards and approaches more effective, providing greater value for money, with countries applying good practice suitable to their local conditions.

A comprehensive scoping report has been produced by the international partners, which highlights the main drivers behind the project, and outlines the contents, format and practical guidance that will be covered in the International levee handbook.

The handbook will give an overview of recent advances and approaches to using existing national and international codes, standards and guidance. It will offer a “decision support” framework for competent engineers, rather than a prescriptive “decision making” code of practice looking at specific challenges during the life cycle of flood defence embankments.

HR Wallingford is leading and coordinating the technical input from the UK and Ireland. Details of the international partners and funding organisations can be found on the project website (www.leveehandbook.net)