EurOtop II to Improve Future Design of Flood Defenses

Reducing the risks of overtopping is essential for the effective design and management of flood defenses, particularly as these defenses are required to meet future conditions, including the impacts of climate change.

HR Wallingford is one of the partners writing the European Overtopping Manual – known as EurOtop – which has now been revised and updated in a second edition.

EurOtop II provides improved guidance predicting wave overtopping at coastal structures as well as at estuary and inland flood embankments and reservoirs.

Most coastal defenses consist of seawalls. These range from simple earth embankments through to vertical concrete walls, and complex structures that can include wave return walls or rock armor. Each structure may have a different overtopping performance.

Using the EurOtop II Manual, engineers can confidently analyse the overtopping performance of any type of sea defense or similar structure.

Dr Tim Pullen, Principal Engineer in Coastal Structures at HR Wallingford, said: “The original EurOtop manual came about in 2007 as a result of research into overtopping processes. Since then, new data have been collated which have further advanced our understanding of these processes, and which have been used to update prediction methods in the manual.”

“For EurOtop II, we have included a completely new chapter with an extended set of case studies. The featured case studies illustrate the use of the various methods for a number of sites in the UK, Belgium and The Netherlands,” added Dr Tim Pullen.

Significant improvements in EurOtop II include a new method for assessing overtopping for slopes with small freeboards; and for the effects of crest walls, reducing potential over-estimates for overtopping discharges. Another upgrade is a harmonized prediction method to simplify the calculation of overtopping for vertical and steep walls, and revised advice on tolerable discharges.

EurOtop II is freely available to download now at: www.overtopping-manual.com.