Transcript presentation
Flood risk, flood prevention and flood insurance in The Netherlands
Karel Heynert & Laurens Bouwer Deltares, The Netherlands
This talk…
The Netherlands - delta of 4 international basins
Amsterdam Rhine Scheldt Meuse Ems Schiphol
4
The Netherlands – protected by levees Surface Area Inhabitants Total
41.528 km² 16,8 million
Vulnerable to flooding
55% 60%
GNP
700 billion $ 65%
Flood protection in The Netherlands (current)
Return periods…
53 flood protection areas (dike rings)
4,000yr
Protection level based on
probability of exceedance
of
design waterlevels
5 different protection standards Procedure in Water Act Formal verification: every 6 yrs
10,000yr 4,000yr 2,000yr 1,250yr
Towards a flood risk based approach…
Decision making based on
flood risk
Still largely an engineering approach, but… Flood risk… Unprotected areas: flood hazard * vulnerability (mapping) Areas with flood defences: (calculations) failure probability * consequences Rationale for investments in flood defences … • Economic viability • Probability of loss of life < 10 -5
Computing flood risk… ?
Computing flood risk…
Potential inundation depth in (meter)
Some points of attention…
‘Indirect’ damage Critical infrastructure Flood protection units interact Potential direct damage per dike ring in M € (in 2020)
Verwachte schade bij optreden overstroming (situatie 2020)
Vlieland Biesbosch Schiermonnikoog Terschelling Eempolder Ameland Gorssel Noord Beveland IJsselland Pernis Friesland en Groningen Arnhemse- en Velpsebroek Zeeuwsch Vlaanderen Ooij en Millingen IJsseldelta Rozenburg Tholen en St. Philipsland Mastenbroek Zutphen Noordoostpolder Goeree-Overflakkee Oost Veluwe Land van Altena Texel Vollenhove Bommelerwaard Zuid Beveland oost Schouwen Duivenland Hoeksche Waard Donge Noord-Holland Wieringen Land van Heusden/de Maaskant Rijn en IJssel Salland Lopiker- en Krimpenerwaard Kromme Rijn Gelderse Vallei Zuid Beveland west Land van Maas en Waal West-Brabant Overstromingskans 1/2000 1/5000 1/10000 1/20000 1/50000 1/100000 Voorne-Putten Eiland van Dordrecht IJsselmonde Betuwe, Tieler- en Culemborgerwaarden Zuid-Holland Alblasserwaard en Vijfheerenlanden 0 10000 20000 30000 40000 50000 60000 Schade (mln euro)
Potential loss of life… Local individual risk of death
P < 10^-7 10^-7 < P < 10^-6 10^-6 < P < 10^-5
P > 10^-5
Flood prone Not flood prone Water Not NL
Time to onset of flooding Preventing loss of life…
Flood protection Flood warning & crisis management Direct (< 6 hrs) Fast (6-24 hrs) Slow (> 24 hrs) 28 april 2020
Flood insurance…
Insurability of flood damage in The Netherlands X Local flood damage
→
ordinary insurance policies
1: Water damage in house (rain) 2: High groundwater 3: Sewer flooding 4: Polder water system
Figure: Matthijs Kok
Insurability of flood damage in The Netherlands X
Figure: Matthijs Kok
Local flood damage
→
ordinary insurance policies
1: Water damage in house (rain) 2: High groundwater 3: Sewer flooding 4: Polder water system
Flooding , due to failure of defences → coverage ??
5: Failure regional flood defence 6: Failure of primary flood defence 7: Unembanked areas
Flood insurance in The Netherlands…
Building and home content policies C rop loss insurance stopped in ‘09 Government compensation act (WTS) New disaster insurance…
Flooding, terrorism, earthquake etc Limited to 75 k € per insured object Limit in nr of households in ‘unit’
Flood insurance pool proposed by Dutch Association of Insurers…
Obligatory, incl. in house insurance!
Annual max. coverage: 5,000 M € Seems rejected by NL cartel authority
Future direction of flood insurance?
Flood risk management policy based on: Prevention Optimal investments Prevention of loss of life High protection levels Infrequent events High accumulation risk Limited flood awareness (?) Public anticipation of role government So where should we with flood insurance?
Mainly for regional water systems? < 100 €/ha 100-1,000 €/ha 1000-10,000 €/ha 10,000-100,000 €/ha > 100,000 €/ha
How to balance between investments in flood protection and relying on flood insurance?