The summer floods in England and Wales cost the UK economy an estimated £3.2 billion, and sadly, caused 13 fatalities. Following the floods, an independent review was carried out by Sir Michael Pitt. Pitt Recommendation 49 called for a national flooding exercise at the earliest opportunity, to test new arrangements put into place to deal with flooding and infrastructure emergencies.
The summer floods in England and Wales cost the UK economy an estimated £3.2 billion, and sadly, caused 13 fatalities. Following the floods, an independent review was carried out by Sir Michael Pitt. Pitt Recommendation 49 called for a national flooding exercise at the earliest opportunity, to test new arrangements put into place to deal with flooding and infrastructure emergencies.
To meet this recommendation, Defra and the Welsh Assembly Government tasked the Environment Agency with organising the biggest civil protection exercise for over 60 years. As one of the Environment Agency’s partners on this project, Halcrow provided crucial expertise to support the planning, design and successful delivery of this unprecedented flooding exercise.
Halcrow’s knowledge and expertise in flood risk, covering all sources of flooding, was employed to design and map a realistic 4 day flooding scenario. Additionally, we helped engage Local Resilience Forums by attending their meetings and providing advice to ensure their own local objectives would be adequately tested by the national exercise. Our team also produced, coordinated and quality checked thousands of ‘injects’ (e.g. e-mails, texts, telephone calls) and associated materials (e.g. weather products, news clips and travel info), which stimulated ‘live play’ during the exercise. During the actual exercise, three Halcrow staff took up technical roles in Exercise Control, making a further valuable contribution to this large and hugely successful flooding exercise.
Exercise Watermark required a large amount of GIS flood mapping to animate the hourly development of the flood extent over the 4 days of exercising. Typically, only maximum extent flood maps were available as output from existing models, so we used our experts to develop practical assumptions about how the maximum extent of flooding from different sources would develop over time. We then prepared bespoke GIS scripts to buffer the flood extents out from their assumed source (e.g. coastal defence line or the centre of a surface water pond) to provide approximate hourly extents, adding a realistic temporal dimension to the flood scenario.
Some of our clients also used Exercise Watermark to successfully test our innovative FloodViewer tool, which serves to support decision making during flood emergencies.