New Approaches for Flood Risk Management in the Netherlands Rijkswaterstaat Corporate Dienst New Approaches for Flood Risk Management in the Netherlands 4th International Symposium on Flood Defence Toronto, Canada 08/05/2008

Rijkswaterstaat Corporate Dienst Outline Background on Flood Safety in the Netherlands Policy Developments Causes Developments Process

Flood protection is crucial for the Netherlands 60% of the country is threatened by floods 70% of the GNP (600 billion US$) is threatened by floods Large cities like Amsterdam and Rotterdam are below sea level

Defence system developed after disasters Afsluitdijk (1932)

The 1953 storm surge disaster

The 1953 storm surge disaster The 1953 storm surge disaster (1800 casualties, 1800 sq. kms flooded) led to the Deltaplan, including: Closure of estuaries Safety standards on an economic basis National dike improvement scheme

Present flood defence system Dunes Levees and space for rivers Dams and barriers

The Flood Protection Act (1996) The Flood protection act dictates: The safety standards per ‘dike ring’ area (freq. of exceeding of design water level) The responsibilities of the parties involved A 5-yearly safety assessment of all primary flood defences Safety assessment & Design of flood is prescribed in guidelines

Causes for New Policy 2005: Policy Evaluation Risk of flooding has grown Standards are not up-to-date Safety Standards are never fully complied Safety Chain / Emergency Management Cycle is not used Attention for Climate Change, urge to be prepared for future New Orleans was a eye-opener Development of Risk-based techniques (FLORIS project)

Present Discussion about Flooding Risk in the NL 1970 2010 (est.) 2005 1950

Process “From the outside inwards” In 2006 several meetings were organized Technical meetings about prevention, spatial measures, safety chain and cost-benefit analysis “Dike-Ring Meetings”, with cross section of stakeholders (not only water professionals) Gathering of ideas for new policy In 2007, the most promising ideas were further investigated Spring 2008: concept of new policy is discussed with stakeholders Fall 2008: policy document

Main Elements in Future Policy General: Risk Based Policy, meaning Multi-layer safety principle Standards based on risk assessment Robust, future based Improvements for prevention system Robustness in the 5-yearly safety assessment, take into account reinforcement period (20 year) Robustness in designing new flood defences Step forward to safety standards in terms of probability of flooding Reconsider safety standards based on CBA and acceptability of casualties (Individual Risk, Group Risk)

Main Elements in Future Policy (2) Overflow-proof dikes or “superlevees”? Compartmentalization of larger dike-rings? Improvements for “Reducing Consequences” Incorporate flood risk in “Water Test” Framework for climate-proof spatial planning Protect Vital functions (electricity, water supply etc.) note: still under debate… Emergency Management Task Force Management of Flooding (TMO), improve emergency organization, exercise “Waterproof” end of 2008 Keep emergency management organization Raise awareness of public and politicians for flood risk management

Challenges Make probability of flooding work in practice: Guidelines for assessment and design based on probability, applicable for waterboards Discussion about height of safety standards Requires lot of data (FLORIS, cost estimates, future scenario’s Combining economical, personal and group risk Differentation of safety standards Communicate change from old to new safety standards Role of Water in Spatial planning Balance between preventive and other measures

Timeline 2008 Flood Safety policy document 2009-2013 Implementation fundamental changes components of new policy Course CBA, financial impact, paper 105, session D 2009-2013 Implementation New standards based on CBA, estimates of casualties, societal discussion Results of VNK/FLORIS Instrument for safety assessment Adjustment Flood Protection Act Synchronisation with EU Guideline for Flood Risk Management 2013 Safety assessment according to new policy

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