1. Water in the Netherlands
Water management in a densely populated delta and the role of controlled drainage
Jan van Bakel

2. Professional career Graduated in 1976 in Wageningen (Hydrology)
In 1976: employee of ICW as head of Department Numerical Modeling
In 1986 Ph.D. ‘Planning, design and operation of surface water management systems: a case study’
From : consultancy company TAUW
: employee Staring Centre -> Alterra
Since consultant (zzp’er); see
Expert in Agrohydrology
Member of the board of the Dutch Hydrological Association (NHV)
trip USA nov 2011

3. Deltaic country Napoleon: Ems Scheldt Rhine Meuse 21-9-2018
trip USA nov 2011

4.
trip USA nov 2011

5. Precipitation and evapotranspiration
Yearly vaules (mm) Monthly values
Precipi-tation
Reference crop evapotr.
Average
827
543
10%-value
626
500
90%-value
1065
584

6. Precipition and evaporation
Yearly values (mm) Monthly values
For Agriculture: mostly too wet, sometimes too dry
Precipitation
Reference crop evapotr.
Average
827
543
10%-value
626
500
90%-value
1065
584

7. Trends Before WW II: land reclamation on a small scale
After WW II: promotion of land reclamation and improvement, to secure food production (autarky)
Intensification of agriculture (Rudy Rabbinge)
Environmental problems (nutrients, pesticides)
Environmental and water management plans
Emphasis on restoration of water systems: water is leading. Romantic hydrology!
Climate change: threats and chances
Recently: use of technology can help to do the job
Controlled Drainage (CD) is a very promising candidate!

8. The main water topics (tasks)
Safety first
4 water tasks:
Water quality: environmental issue
Water shortage: both for agriculture and nature
Water surplus: for agriculture and civilians
Salinisation : for agriculture (and nature)
trip USA nov 2011

9. Things are changing… Climate change Land subsidence in 2050
Demographics
Land use
Water use
trip USA nov 2011

10. Controlled Drainage (CD)
Farmers didn’t care about N and P loads to surface waters unless ..
Farmers didn’t care about peak discharges unless …
Farmers didn’t care about drought effects on nature
But the times …..
CD with smaller drain spacing and higher drainage base offers new possibilities
trip USA nov 2011

11. Types of drainage (1) Phreatic level Drainagebase controlled dr.
Undrained
1,00 m
Phreatic level
Conventional dr.
Drainagebase controlled dr.
0,60 – 0,90 m
1,00 m
1,10 m
Phreatic level
drains

12. Types of drainage (2)
Conventionally drained, made composite afterwards
1,00 m
1,00 m
Phreatic level
0,60 m
drains
collector
Composite, controlled drainage; smaller drain spacing
1,00 m
1,00 m
0,60 m
collector

13. Some model results (from SWAP) for CD, without forecasting
Groundwater depths
Water quality
Peak drainage fluxes
trip USA nov 2011

14. Model results with SWAP for groundwater levels, CD with 30 cm variation and fixed data

15. Model results with SWAP on groundwater levelsCD

16. N and P loads on surface waters
N: denitrification
P: immobilisation
Induced seepage accounted for by Δh/seepage resistance, calculated by a regional model N
kg/ha/yr P
Undr.
Conv. CD
trip USA nov 2011

17. Peak discharges Standard Undr. discharge cap. CD Conv.
Highest discharge (mm/day) CD
Conv.
trip USA nov 2011
years

18. In conclusion
Water management in the Netherlands has a ‘rich’ tradition
The economic developments after WW II caused a distortion of water systems
Climate change will enhance the problems
The restoration can be done in a ‘romantic’ and/or technological way
Controlled drainage, with the use of new technologies and techniques (remote control, now- and forecasting), has much potential
trip USA nov 2011

19. More information ‘Water in the Netherlands’: www.nhv.nu
‘Water Policy in the Netherlands’, Reinhard and Folmer (eds).
SWAP-model:
trip USA nov 2011

20. Water in the Netherlands
Water management in a densely populated delta and the role of controlled drainage
Thank you for your attention!