An overview of current knowledge and challenges in predicting breach through dams and levees

Predicting breach erosion processes is essential for the effective risk management of both dams and levees. This has been recognised for decades, with efforts to develop breach prediction models dating back to the 1960s and 70s. Over the past decades, numerical methods and computing have advanced, but since breach processes depend upon a combination of hydraulics, soil mechanics and structure response, the challenge to accurately predict breach formation for all scenarios has yet to be met. Research into different aspects of breach, and in particular into the soil erosion processes of different soils in different states, is starting to show how different erosion behaviour can arise for different hydraulic load and soil conditions. This new knowledge and understanding then needs to feed through into predictive and probabilistic models that industry can use in analysing and determining flood risk from breach. This paper provides an overview of current knowledge and practice in predicting the different types and phases of breach showing how research efforts around the world are progressively piecing together the jigsaw puzzle of processes that affect and dictate how breach initiates, forms and grows through dams and levees. This includes reference to recent and ongoing work in the France, Spain, the UK, the Netherlands and the USA, and shows how these research efforts are feeding into models and solutions suitable for industry application.