Dutch approach for setting GEP (and MEP)

Marcel van den BergMinistry of Infrastructure and Environment /

Rijkswaterstaat

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In this presentation

• General description development of GEP in 4 steps• Methods for estimation of effect of measures• Examples of GEPs• Measures and more• Discussion and Conclusions

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Method GEP: CIS guidance 2003

Present ecological status

Reference condition

eco

log

ical st

atu

s/E

QR

hydromorphological alteration

mitigationMEP

GEP

Alternative approach (Prague, 2005)

all possible measures minus measures with

small ecological effect

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GEP derived in 4 steps 1: all measures

• EC and national policies (Nitrate- and Urban Wastewater Directive, national program on diffuse pollution, etc)

• All other measures (derived from a national database)Chem-istry

Hydro-morphology

Phyto-plank-ton

Other flora

Macro-inverte-brates

Fish

Waterlevel management x x

Repositioning of dykes x x x

Fish management x x x x

Fish migration x x

Wastewater treatment + x x

etc

2: all possible measures

3:

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Step 4. Calculation GEP

1. Estimation effect for measures in EQR units per body2. Added to present ecological status (for each quality element)3. Correction for combined effect4. Validation by 2nd opinion of experts

Result of the 4 steps: a national database with for each water body • All measures• Size• Costs• Responsible authority• Numerical GEP

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Methods for estimation of effect of measures

• Ex-ante evaluation (=multi-variate/statistical model)– National data– Used for national policies and decision making– Method not used in the RBMPs

• WFD explorer (=tool kit with different types of models)• Practical knowlegde / expert judgement

• In principle: quantitative and expressed at metric for natural water body

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Comparability GES and GEP

GES

Natural river

IC type RC1/4

national type R5

0.8

0.6

0.4

0.2

1.0

EQR

GEP

Modified river

0.28

0.42

0.15

Objective in RBMP

EQR

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Comparability GES and GEP - results(Rhinedelta, 490 of 723 Dutch waterbodies)

Lakes GES GEP(avg.)

phytoplankton 0.6 0.58

other flora 0.6 0.53

macro-invert. 0.6 0.42

fish 0.6 0.51

Rivers GES GEP(avg.)

phytoplankton

other flora 0.6 0.54

macro-invert. 0.6 0.45

fish 0.6 0.41

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Example Haringvliet and GEP for fish

• Haringvliet sluices: fish migration obstacle

• Dam function is: safety and fresh water supply

• RBMP: sluices are allowing passive and active migration of fish (e.g. 75% of time open)

• Effect is estimated for fish metric as 0.20 EQR units (=improvement of one quality class)

• Direct connected above stream waters have get similar effect

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GEPs of Haringvliet/Hollandsdiep in RBMP(now tidal River former Estuary)

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Overview all measures: RBMP’sHydromorphological measures (WFD art 11.3i)• 1727 km restoration of land-water gradients in lakes and canals (3357)• 729 km restoration of land-water gradients and re-meandering in rivers

(930)• 1362 ha creation of wetlands (704)• 635 solutions for fish-migration at weirs (884)• Water level management, creation of side channels, etc

Supplementary measures (WFD art 11.4)• Fishmanagement (‘biomanipulation’)• Management of macrophytes

• Education, further research, etc

4.2 billion € extra costs

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Discussion

• Numerical GEPs help us to be:– compliant with WFD– transparent about the expected effect of measures taken/planned– flexible in measures as long as same effect is achieved

• The method and value of deriving GEPs is less important than its result:– a set of measures and its positive effects– (potential) negative effects on the use– costs of measures