Presentation by Joachim Hunink (Waterboard Aa and Maas, Netherlands) at the Hydrology Suite User Days (Day 1) - Hydrology Suite introduction and River Basin Management software (RIBASIM), during the Delft Software Days - Edition 2023 (DSD-INT 2023). Tuesday, 28 November 2023, Delft.

1. Parameterization of RIBASIM and flexibility in the lumped
approach for Dutch Waterboard Aa and Maas
Joachim Hunink 28 November 2023

2. What does the Aa and Maas water authority do?
Safe, sufficient, clean water
The regional water authority Aa and Maas works around the
clock to provide safe, sufficient, clean water. Every day, we
inspect and maintain dikes and purify 300 million liters of
wastewater. We do this for over 778,000 residents, for
businesses and of course for the environment in the east of
Brabant.
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Clean
Water
Sufficient
Safe

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Where do we operate?
Sewage treatment plants:
Aarle-Rixtel
Asten
Dinther
’s-Hertogenbosch
Land van Cuijk (Haps)
Oijen
Vinkel
Headquarters:
’s-Hertogenbosch
District offices:
Cuijk
Deurne
Lith
Loosbroek

4. • Mostly sloping sandy soils.
• East of the Peelhorst, the water flows through the Raam
water system to the river Maas.
• On the west side, the water flows towards the river Aa,
which empties into the Maas near ‘s-Hertogenbosch.
• The northern part of our working territory consists of clay
polders.
Most important bodies of water:
Maas, Aa and Raam rivers
Zuid Willemsvaart channel
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Territory information

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Groundwaterlevels
Winter Summer

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Geological cross section

7. • Lowering of groundwater levels in summer, drought in groundwater depended nature areas, less dicharge
in rivers, waterquality (blue-green algae), flooding in winter and summer.
• Drought in nature and agricultare areas
• Extremes in weather (wet and dry)
• Climate change
• Increase in water demand (ground and surface water)
Since 2021 “Groundwatercovenant” with different water partners in the south of the Netherlands; goal to
work together on recovery of the (ground) water system.
Water Framework Directive 2027; a.o. protection of inland surface waters and groundwater bodies
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Challenges in the regional watermanagement

8. • Regional Groundwatermodel – iMOD (MODFLOW)
• Resolution from 25m
• Easy submodels for local applications
• Based on MODFLOW 2005, in transition to MODLFOW6
• Model used by hydrologist of waterboad and consultancy
• Surface water models -
• D-Flow FM models of the Delft3D FM Suite 1D2D
• Detailed 1D and 1D/2D surface water model
• Rainfall runoff models
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Hydrological modelling at Aa and Maas
Groundwater flux = boundary
Surfacewaterlevel and water
availability = boundary

9. Why integrated modelling?
• Better estimate of the complete hydrological waterbalance.
• Improve interaction groundwater – surface water interaction in calculations
• Better calculate the effect of measures on groundwaterlevels and water distribution
• Availability of surface water (for sprinkling, waterquality, industry)
Goal is to improve the understanding of the system to improve support policiy maker
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Integrated modelling

10. We aim for different hydrological models depending on the application
• Detail calculations groundwater-surface water interaction: D-Flow FM - MODFLOW
• Regional scale groundwater-surface water interaction: RIBASIM - MODFLOW
• Effect on possible measures, local and regional
• Reduction of irrigation from groundwater
• Increase of surface water availability from de Meuse
• Changes in weir levels or filling up ditches
• Changes in de drainage systems
• Support of dammage claims
• Effects of changes of weirs level on the groundwater levels
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Possible applications

11. Pilot case Catchment Hooge Raam
• Pilot of RIBASIM software development project of the regional
surface water modules in RIBASIM
Catchment details:
• Small catchment (7x7 km), no external water supply, groundwater
levels in summer below bed level of the ditches, automated and
manual weirs, irrigation from groudwater.
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RIBASIM - regional surface water module