Quirijn Lodder About myself: Work: Rijkswaterstaat (National - - PowerPoint PPT Presentation

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Quirijn Lodder About myself: Work: Rijkswaterstaat (National - - PowerPoint PPT Presentation

Oct 24, 2022 262 likes •643 views

Asset management of the Dutch coast: Policy and Practice Quirijn Lodder About myself: Work: Rijkswaterstaat (National Government) equivalent of Environment Agency Tasks: Technical Management of the Dutch Coastal Nourishment

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SLIDE 1

Asset management

  • f the Dutch coast:

Policy and Practice

Quirijn Lodder

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SLIDE 2

Rijkswaterstaat 2

About myself:

  • Work:

– Rijkswaterstaat (National Government) equivalent of Environment Agency

  • Tasks:

– Technical Management of the Dutch Coastal Nourishment Program – Advise Flood Risk Management projects

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SLIDE 3

Rijkswaterstaat 3

Daily circumstances Gradual structural erosion Beach, dunes and coastal functions are preserved Compensate erosion Extrem e stormsurges Severe instantaneous erosion Assessment of Flood Risk, reinforcements when necessary Flood Risk is at acceptable level

Coastal Management Policy Coastal Recession

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Rijkswaterstaat 4

Beach 1945

Beach 1990 / present

Structural Erosion

World War II bunkers

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Rijkswaterstaat 5

Coastal Erosion: Egmond aan Zee

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Rijkswaterstaat 6

Coastal Erosion: Egmond aan Zee

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Rijkswaterstaat 7 De kust van Vlieland 7 Oktober 2011

Vlieland

1 6 8 8 1 7 9 5

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SLIDE 8

Rijkswaterstaat 8

Compensation of structural erosion

Daily circumstances Gradual structural erosion Beach, dunes and coastal functions are maintained Compensate erosion Extrem e stormsurges Severe instantaneous erosion Assessment of safety, reinforcements when necessary Safety against flooding is secured

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Rijkswaterstaat 9

Coastal evolution

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demand < supply demand = supply demand > supply surplus balance deficit

Measured Sea Level Rise Around 20 cm/ century

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Rijkswaterstaat 10

Planning of Nourishments based on Reference Coastine (BKL in dutch)

  • Compensate erosion, preserve “sandy” system
  • Yearly: Measure, Asses, Plan Nourishm ents
  • Reference Coastline:

– Preserve existing coastal functions (protection against flooding, structures on the dunes, dune habitat, recreation, fresh water extraction… .)

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Rijkswaterstaat 11

Preserve sufficient sediment in the active coastal zone

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Rijkswaterstaat 12

Why do we use sand?

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Rijkswaterstaat 13

3 level strategy

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  • 1. Do nothing
  • 2. Buffer
  • 3. Consolidate
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Rijkswaterstaat 14

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Rijkswaterstaat 15

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Rijkswaterstaat 16

Costs

  • Yearly budget, approx.

55Meuro/ 40 M GBP

  • Down from 70 Meuro in

2009

  • Efficiency: 4 year plan

vs annual plan

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SLIDE 17

Rijkswaterstaat 17

Type schip Contract 1: > 12 m draught Contract 2: < 6 m draught Contract 3: ca.7 m draught Goal maximize competition. Per contract a maximum price. Tenders above are not valid. Option charter a ship

Tendering

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Rijkswaterstaat 18

Sequential tendering

  • Friday contract 1
  • Tuesday notify all contractors who put in a bid
  • Friday contract 2
  • Tuesday notify all contractors who put in a bid
  • Friday contract 3
  • Tuesday notify all contractors who put in a bid
  • Finalize the contacts.
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Rijkswaterstaat 19

Ensuring tolerable flood risk

Daily circumstances Gradual structural erosion Beach, dunes and coastal functions are preserved Compensate erosion Extrem e stormsurges Severe instantaneous erosion Assessment of safety, reinforcements when necessary Safety against flooding is secured

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Rijkswaterstaat 20

  • Safety standards
  • A flood defence should be

able to with stand the fixed standard Current standards

  • 1/ 10.000 central Holland
  • 1/ 4.000 rest of the coast
  • 1/ 2000 and 1/ 1250 inland

rivers

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Rijkswaterstaat 21 Figuren in huisstijl - Kant & klaar 21

Sedimentation Erosion line Mean sea level Storm surge level Remaining strength

Safety against flooding

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Rijkswaterstaat 22

Safety standards

  • All dutch levees have to meet a fixed “safety

standard”

  • In other words: the accepted probability of

breaching of a levee is set by the Water Act (the standards are given in next slide)

  • When insufficient Levee’s are reinforced
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Rijkswaterstaat 23

Seaward dune extension of about 42 meter Water defense (dike and sand) is positioned seaward of boulevard (boulevard area becomes protected) Space for new developments on the boulevard (economic impulse)

Example Noordwijk: Dike in Dune (2007-2008)

www.kustvisiezuidholland.nl

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Rijkswaterstaat 24

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Rijkswaterstaat 25

Towards new safety standards

  • Current safety standards (embedded in Water Act) are derived

from ‘expired’ risk- and cba analysis (late 1950’s)

  • Hence: current safety standards lead to suboptimal investments

in flood risk reduction (now and in the future)

  • S

ince 1990, ongoing work to gain insight to update the standards

  • 2014 first “draft” of new standards have been set
  • 2017 finalize within the legal framework
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SLIDE 26

Rijkswaterstaat 26

  • Safety standards
  • A flood defence should be

able to with stand the fixed standard Current standards

  • 1/ 10.000 central Holland
  • 1/ 4.000 rest of the coast
  • 1/ 2000 and 1/ 1250 inland

rivers

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SLIDE 27

Rijkswaterstaat 27

potential flood risk vs “actual” flood risk

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Rijkswaterstaat 28

Policy objectives (2050)

Letter to parliament (April 2013):

  • 1. Provide a solidary baseline for personal safety

Associated Risk metric: Local I ndividual Risk 1 0 -5 per year

  • 2. Prevent large numbers of fatalities and large

economic damage as much as possible

Associated Risk metric: Societal risk / Econom ic risk ( CBA)

  • 3. Prevent the loss or failure of vital / vulnerable

national assets as much as possible

Associated Risk metric: Econom ic risk ( CBA)

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Rijkswaterstaat 29

Level of standard: towards tolerability

Local individual risk

10-4? -> CBA will overrule 10-5? -> tolerable? 10-6? -> too strict with respect to floods as non man-made disaster

.

CBA

Optimizing economic risk reduction vs costs

Economic risk investment

€

Total cost

‘take the strictest’

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Rijkswaterstaat 30

LIR 2020

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Rijkswaterstaat 31

Economic risk 2020

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Rijkswaterstaat 32

LIR 2020 LIR 2050

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Rijkswaterstaat 33

Economic risk 2020 Economic risk 2050

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Rijkswaterstaat 34

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Rijkswaterstaat 35

Governance, key aspects

  • Water Act

– Compensate structural erosion (Tool: reference coastline, helps with transparency and measure performance) – Safety levels for flood defences

  • Federal funding

– Nourishments – Reinforcem ents flood defences (50% )

  • Local funding

– Maintenance of flood defences – Reinforcem ents flood defences (50% ) – Improvements to local infrastructure (f.i. beachfront)

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Rijkswaterstaat 36

Thank you for your attention

Quirijn Lodder, Rijkswaterstaat