Developments in the management of flood defenses and hydraulic infrastructures in The Netherlands

Bas Jonkman, Professor of Hydraulic Engineering at Delft University of Technology

Large parts of the Netherlands are at risk coastal and river floods. These flood prone areas are protected by a system of flood defences with a length of almost 3800km. The management, maintenance and reinforcement of the dikes, dunes, and storm surge barriers requires continuous attention and knowledge development. This presentation highlights recent developments in the flood risk management in the Netherlands and approaches for asset and life cycle management for flood defences.

Firstly, the new flood risk management policy is introduced. The safety standards for flood defences in the country  have been revised recently on the basis of a nationwide risk assessment and consideration of both economic and risk to life. The presentation will outline the methodologies (as well as results) of the nationwide flood risk assessments. The implications for the Dutch flood management policy and some of the new strategies (e.g. room for rivers, mega nourishments along the coast and innovative flood gates) are highlighted.

The second part of the presentation focuses on challenges and developments in asset and life cycle management for some of the Dutch flood defences. One example that will be highlighted concerns the probabilistic management and maintenance of storm surge barriers and their adaptation to sea level rise. A second example concerns the implementation of building with nature (BwN)interventions. It will be discussed how the dynamics and uncertainties in these types of solutions are taken into account in management and decision making. Finally, it will be discussed how concepts such as past performance and life cycle costs are taken into account in reinforcements of flood defences in the Netherlands.