1. 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

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

3. 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

4. Defence system developed after disasters
Afsluitdijk (1932)

5. The 1953 storm surge disaster

6. 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

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

8. 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

9. 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)

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

11. 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

12. 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)

13. 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

14. 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

15. Timeline 2008 Flood Safety policy document 2009-2013 Implementation
fundamental changes
components of new policy
Course CBA, financial impact, paper 105, session D
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

16. Questions ??