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Low flow management in Wallonia
ir Philippe Dierickx NHV, Maastricht, 24 october 2014
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Introduction
Water uses and drought impacts
Complex low flow management examples
State of art in Wallonia :
Observations
Forecastings
Real-time management
Summary
Wallonia
Flanders
Bxl
Netherlands
France
Lux
Germ
an
y
Meuse (Maas): 12.355 km²
Escaut (Schelde): 3.774 km²
Rhine : 767 km²
Seine : 40 km²
TOTAL: 16.936 km²
~18.000 km of rivers
River basins of Wallonia
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Wallonia has a complex and intensive use of its water ressources for :
Inland navigation
Drinkable water
Hydraulic power production
Thermic and nuclear power plants cooling
Agriculture
Tourism
More critical because :
Needs are growing
Environment rules are more important (fish migration, water quality…)
Impact of global warming scenarios
Economic issues
low flow management is necessary to aim different and sometimes conflicting goals !
Water uses on the walloon river network
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Wallonia has a typical north-west continental climate with, usually:
stratiform rainfalls or snow events filling underground and reservoirs in winter
convective events with heavy rainfalls in summer
droughts are mainly observed during fall in september and october
variable: droughts are sometimes observing during spring or at the beginning of winter
What’s a drought for Wallonia ?
there is no legal definition, as statistics or threshold
some local definitions exist but for only specific purposes as intakes / oulets
a situation for which one some actions must be done to limit the consumption of water
Droughts in Wallonia
450 km of navigable waterways
60 % of controled rivers
40 % of canals
Navigation
From 300 to 9.000 T ships
• 40 weirs on controled rivers
• 80 locks
water consumption
water regulation
Weirs and locks Navigation
New locks 2015
New lock 2017
New locks 2025
Navigation
Drought impacts on navigation
Resizing of locks will increase the water consumption
Resizing of locks should increase the navigation
Navigation will be more sensitive to droughts (even without climate changes)
Difficulties to maintain water levels for full loaded ships
More waiting time at locks to reduce consumption (ships gathering)
Economic impacts
Projects:
Improve the regulation of water to mitigate loss of water
Optimize water supplies through reservoirs
Reduce the leaks at locks
Optimize the traffic management
Use pumping station with cost optimization
Upper Maas
1 power plant
+ 3 projects
Maas
6 power plants
Sambre
3 power plants
+ 3 projects
Hydraulic power plants on navigable waterways
EDF-Luminus
Energie Fleuves
Muyle
Projects
Mérytherm
Albert Canal
1 under constr.
Hydraulic power plants
Hun Marcinelle
Monsin
Total: ~80 MW
Droughts decrease power production of sustainable energy
Thermic and nuclear plants cooling
Tihange: 3.000 MW
Drought means slow velocities and less dissipation of hot water returned by plants
production could be limited (especially during hot weather conditions)
economical impacts are quite important
Reservoirs • 9 reservoirs: 5 public, 4 private
Reservoirs
• Navigation support
• Drinkable water
• Flood control
• Power production
• Tourism
La Gileppe
Eau d’Heure reservoirs
Eupen
Nisramont
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Reservoirs
Eau d’Heure volumes
Theoretical capacity Effective capacity
Water supply for
navigation
After the 2003 drought, almost 3 years were
necessary to get back to full capacity
10.106 m³
Drinkable water
Groundwater
Surface water
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Drinkable water
During extreme droughts, some practices
could be forbidden to avoid waste of water
but hard to control
Tourism
Some reservoirs are recreational areas:
supply water for navigation during summer is conflicting
Some rivers are famous for kayak
lovers but activities are stopped
during droughts due to
environmental troubles
Small waterways are
maintained for
tourism navigation
Fish migration
Fish passes require water consumption
Nowadays, reserved discharges are enforced to maintain enough water above weirs to
reduce fish mortality through power plant or to keep enough water downstream
reservoirs
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Charleroi-Brussels Canal
The canal ensures the link between the Maas Basin and the Schelde basin
from south to north (Flanders and Brussels) and west (Liège) to east
(Tournai through Center Canal)
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Charleroi-Brussels Canal
Water supply &
power
Navigation & fish migration
Natural flow
Pumpings
Natural flow
Natural flow
Highly complex water management for :
Navigation
Environmental issues
Costs
Benefits
Tourism
request hydrologic, hydraulic and economic models !
Charleroi-Brussels Canal
Lower Maas Monsin
Netherlands
Common M. Lixhe
Albert Canal Lanaye
Genk
Navigable Maas
Wallonia
Flanders
Flanders
Jeker
Liège
Maas downstream Liège (Luik)
Q Liège > 60 m³/s Waterlevel of 60 m DNG to keep
permanently on a 60 km reach
Lower Maas Monsin
Netherlands
Common M. Lixhe
Albert Canal
Lanaye
Genk
Navigable Maas
Lock
Monsin
Lock
Visé
Diverse
Flows
Borgharen Non navig.
Maas
Juliana
Canal
Zuid
Willems
vaart
Wallonia
Flanders
Flanders
Berwinne
Fishways
Jeker
Liège
Maas downstream Liège (Luik)
Q Liège < 60 m³/s
Maas downstream Liège (Luik)
Year 2011: several low water events
7 months
During droughts, the Canal consumption could be close to
the discharges in Liège
Normal waterlevel for navigation: 60 m
59 m
Maas downstream Liège (Luik)
Year 2011: several low water events
1 m
Maas downstream Liège (Luik)
In 2015: new lock (L225 x W25 x H14) in Lanaye with a pumping station and turbines
Permit (fish migration) :
• obligation of pumping if Q Lixhe < 50 m³/s
• turbines allowed if Q Liège > 120 m³/s
Challenge: how to keep water levels during droughts ?
different outlets : locks of Lanaye, Genk, Monsin dam & power plant
different managers : Wallonia (SPW), Flanders (Scheepvaart), Private company (EDF-Luminus)
keep enough water downstream
respect environmental permits
optimize benefits / costs
improvment of hydrologic knowledge
simulation models (hydraulic & economic)
agreement between partners
real-time management
Maas downstream Liège (Luik)
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Today on the walloon hydrologic network
• main observed consequences of droughts are related to navigation
• just enough water to avoid problems for drinkable water and refreshment of
industries
• BUT we never had to face up to 2 consecutive years with low water
the phreatic aquifer was always reloaded
close to the limits
• the probability of this « worst case scenario » is raising due to growing needs and
climate change
• politicians and inhabitants are not enough concerned by water scarcity
• however, some actions are on the way…
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Observations
A good measurement is ALWAYS better
than an excellent calculation or estimation !
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Rainfall network and weather radars
RMI
Wacondah network
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Wacondah network
140 stations on navigable waterways and tributaries.
5’ step (GPRS)
Water level network
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Aqualim network
180 stations on non navigable waterways
Water level network
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Discharges measurement by rating curves
Propeller
ADCP
Increasing of measurement during
low water as rating curves are more
sensitive to :
- cross sections changes
- grass inside the river
- artificial perturbations
Accuracy must be improved
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Haccourt Visé
Amay
Waulsort
Ronet
Tournai Solre
Châtelet
Tailfer (2015)
Marchienne
Lessines
Huy
Monceau
Clabecq (2015)
Discharges measurement by ADM
Best solution for flow measurement
on navigable waterways
Clomines (2016)
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Piez’eau network
400 stations including 150 in real-time
Groundwater network
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Weir sensors
Accuracy is important for flow
management
Weir sensors calibration
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For instance, we have to keep 20 cm
above some weirs on the Maas river
for fish migration
Leaks estimation
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On field measurement
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Database and series
Requirements:
telemetry : mainly GPRS or optical fibers
efficient quality control
automatic
manual
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Drought forecasting
Weather models
Ensemble predictions
NWP
Hydrologic observations
+
Stochastic models
Potential / effective evapotranspiration
(LSA SAF)
+
Not accurate !!!
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Qr (t,x)
Zr (t,x)
Y
X
Qb (t) Qin (t)
PLC Zamont (t)
Phausse (t)
Ovanne (t)
Qc (t)
PLC
Zc (t) Qmesuré (t)
Z* = Consigne
Development of simulation models for water management
Water levels AND discharges
regulation
With economical issues
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Water level regulation could be… very bad
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Mesure de niveau
amont Interface ISN-02
Module de filtrage
AE-95
AFFICHAGE
18 bits
4x4 BCD
1 Valid.
1 Déft4 - 20 mA
Cap
teur
Lig
ne
Inte
rfac
e
Conta
cts
Tendances
Hauteur
(cote état-major)
Communication
RS232 ou RS485
Vers relayage
des organnes de
commandeAFFICHAGE 0 3
0 3
>
<
=
1 5
1 8
>
<
=Roues codeuses BCD
Hauteur
filtrée
1 5 1 8
BCD
Communication
RS232 ou RS485
Roues codeuses
Module de temporisation
et de commande des relais
AE-96
Hauteur de
référence
Comparateurs à
fourchette
2 x CSP 17/005
Délai
Hydrologic observations
database
Structure monitoring database
Automatic local
management
Structure commands
Optimization of local flows including global informations
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Progression…
time to think about water scarcity !!!
CONTACT
Service public de Wallonie
Direction générale opérationnelle Mobilité et Voies hydrauliques
Boulevard du Nord, 8
B-5000 NAMUR
BELGIQUE
Tél: + 32 81 77 29 83
Fax: + 32 81 77 37 88
Thank you