II
1
Surface water characterization
Introduction
Pursuant to Annex II of the WFD, surface water must
be divided into surface water bodies, and the member states must carry out a first characterization of
these surface water bodies. Therefore, the surface
water must first be divided into different categories.
The WFD distinguishes the following categories: rivers, lakes, transitional waters and coastal waters.
Then, a typology must be developed for each category of surface water, and the water bodies must be
delineated in a number of steps. The European CIS
guidance document “Identification of water bodies”
describes the general method to be followed.
In addition, type specific reference conditions must
be established for these water bodies.
In the paragraphs below, the terms “typology”, “water bodies” and “reference conditions” are described
in short.
Paragraphs 2 to 5 of this chapter then give, per category, an overview of the typology and the delineated water bodies. Then, the reference conditions that
have already been developed per region are compared and the current quality of the surface water is
described. Map 6 (p. 24) shows the categories and
types of all surface waters in the district.
More detailed information about this, such as methods used per region to work out the typology and
to delineate the water bodies, can be found in the
thematic report “Fresh surface water”, drawn up by
project group P09, and in the thematic report “Coastal and transitional water”, drawn up by project group
P10.
tems: system A and system B. If they use system B,
the member states can define a number of optional
descriptors, in addition to the obligatory descriptors.
The typology resulting from system B must achieve
at least the same degree of delineation as would be
achieved using system A.
1.2 Water bodies
According to the CIS document “Identification of
water bodies”, a number of steps must be followed
to delineate the surface water bodies. The first two
steps consist in classifying the surface waters in categories and types. In the next steps, the surface waters must be classified further on the basis of criteria to be established by the member states (physical
characteristics, impact of significant pressures, a/o
hydromorphological pressures, protection status, …).
Then, the delineation of water bodies consists in delineating a new water body whenever the value of a
criterion changes in the surface water network. As
a result, each water body must be homogeneous as
regards the values of the established criteria. Going
through these steps on the basis of the established
criteria is considered as an iterative process.
1.3 Reference conditions
Pursuant to Annex II, § 1.3 of the WFD, for each type
of surface water, type specific biological reference
conditions must be established. The reference status
of a surface water type is defined as the values of
the quality elements reached in places that are found
in the reference status, and which are therefore not
subject to any human pressure. The high ecological
status is reached when only very slight differences
with respect to the reference status are observed.
1.1 Typology
The typology is used to characterize surface water on
the basis of physical parameters that have an ecological relevance. For each water type, the specific
reference conditions will be described that form the
basis of an ecological assessment of the status of
the surface water. This makes it possible to carry out
validated, transnational comparisons of the ecological status of water bodies.
Annex II of the WFD offers the member states the
choice between two surface water typification sys-
The CIS guidance document “Guidance on establishing reference conditions and ecological status class
boundaries for inland surface waters” describes a
general method for establishing these reference conditions for fresh surface water. For coastal and transitional waters, the CIS guidance document “Typology,
reference conditions and classification systems for
transitional and coastal waters” is used.
For a surface water body, the classification according
to ecological status must be done on the basis of Ecological Quality Ratios or EQR, which are established
21
II.
Surface water characterization
for biological quality elements. An ecological quality
ratio expresses the ratio of the observed value of the
biological parameter or index concerned with respect
to the value of this parameter or index in the reference status. The overall assessment of the ecological
quality is further based on supporting physico-chemical and hydromorphological elements.
For rivers and lakes, the WFD takes into account the
following biological quality elements: phytoplankton,
macrophytes and phytobenthos, benthic invertebrate
fauna and fish fauna. For transitional waters, they are
phytoplankton, macro-algae, angiosperms, benthic
invertebrate fauna and fish fauna; for coastal waters
phytoplankton, macro-algae and angiosperms, and
benthic invertebrate fauna.
1.4 Environmental objectives
Translated into environmental objectives, a good
surface water status means that both the ecological
status and the chemical status of the surface water
are at least good. The reaching of a good ecological status or not by surface water is determined by
a complex interaction of a whole series of factors.
The ecological status is first reflected in biological
elements: water flora, macro-invertebrates and fish
fauna. The hydromorphological characteristics and
the physico-chemical quality of surface water have a
major impact on life in the water body. The combined
effect of all these factors will determine the ecological status. The good chemical status requires that the
environmental quality standards are met for a certain
number of specific pollutants for which a standard
has been or will be established at European level.
2
Rivers
2.1 Typology
All Scaldit partners have used system B to establish a
typology for rivers. No common types could be established yet for the Scheldt IRBD, because the partners
used different descriptors, a/o because of different
initial situations and because of national limitations.
Table 7 gives an overview per region of the descriptors used for the typification of rivers. For the Flemish
Region, Brussels Capital Region and Walloon Region,
the typology was developed on a regional level, for
France and the Netherlands, it was developed on a
national level.
The use of the descriptors in table 7 enabled each region to define a number of river types for its own part
of the Scheldt IRBD. The types present in the Scheldt
IRBD are given in table 8.
A comparison between the types defined per region
shows that the ecological conditions for the Flemish
and Dutch polder watercourses (see § 3 Lakes) and
the French Moëres watercourses are approximately
the same, so that further attuning of these types
must be possible in the future. Therefore, the water
characteristics and the ecological objectives should
be similar.
The Dutch polder watercourses, however, were categorized as lakes, while these surface waters in France
and in the Flemish Region belong to river types. In
the whole area from Dunkerque to Goerree-Overflakkee, the characteristics of these watercourses are
similar, as they all have a low flow rate and most of
them are artificial or heavily modified waters.
It is also important to know that the river and brook
types from the French clay-sand deposits (types 1,
2, 6, 8 and 9) are comparable to the types from the
Flemish sand/loam – loam area (types 1, 3, 5 and 6)
and the Walloon loam region (all types). The Kempen brooks in the Flemish Region (types 2 and 4) are
similar to the middle course/lower course on sand in
the Dutch typology.
However, in the Netherlands, this only concerns a few
brooks in province Noord-Brabant. Almost all fresh
surface waters in province Zeeland are artificial and
classified in the lakes category.
International attuning will focus on making the quality objectives comparable.
It is also noteworthy that the Brussels Capital Region
is surrounded completely by the Flemish Region. The
Flemish and Brussels partners therefore decided to
use the same typology.
In general, inside Belgium (Flemish Region, BCR and
Walloon Region), the types that have been developed
22
2
Rivers
Table 7 : Descriptors used for the typification of rivers per region
France
Walloon Region
Hydro-ecoregion:
Hydro-ecoregion:
Clay-sand deposits
(subdivided into:
• Flandres intérieures
• Moëres
• Thiérarche
• Douai-Condé)
Loam
Flemish Region and
BCR
Hydro-ecoregion:
Kempen (sand)
Sand/loam - loam
Netherlands
Geology:
Sand
Polders
Lime plateaus
(subdivided into:
• Boulonnais
• Auréole du Crétacé
• Haute NormandiePicardie)
Strahler order:
Catchment area (km²):
Catchment area (km²):
Small (1-3)
Brook (≥ 10 – 100 km2)
River (100 – 1,000 km2)
Small brook (< 100 km2)
Large brook (100 –
300 km2)
Small river (300 –
1,000 km2)
Large river (1,000
– 10,000 km2)
Medium-sized (4-5)
Large River (1,000
– 10,000 km2)
Slope:
Slight (< 0.5 m/km)
Medium (0.5 m/km
– < 7.5 m/km)
Strong (> 7.5 m/km)
for the river category are based on the size of the
catchment area and therefore there is a great correspondence between them.
The typologies developed by France and the Netherlands differ more. Indeed, in France, the Strahler
order was chosen as a descriptor for the size of the
watercourse, as France has the opinion that it reflects
better the changes in size of a watercourse.
In the Netherlands, there are almost no natural river
types and almost all fresh surface water is classified in
the lake category. Indeed, a major part of the Dutch
share of the Scheldt river basin district lies below sea
level, and drainage is controlled by man. In dryer periods, this means that there are prolonged periods
of stagnation. The ecology of such (semi-)stagnant
surface waters is closer to the ecology of lakes than
of rivers.
The differences in type of the cross-border watercourses don’t seem to pose a serious problem. However, the harmonization of the reference status linked
with this, and the corresponding assessment of the
water bodies concerned on both sides of each border,
must be aimed at.
Catchment area (km²)/
width:
Middle course / lower
course (10 – 100 km2)
Slope:
< 1 m/km
2.2 Water bodies
It was not possible to develop harmonized methods
for the whole river basin district, as the partners developed their own method at national/regional level.
As a result, the water bodies in each regional part of
the Scheldt IRBD are delineated in a different way.
An overview of the criteria used to delineate the river
water bodies and the number of resulting water bodies is given in table 9.
Table 9 shows that the criteria used by the different regions differ rather greatly and only the criterion
“categories” is used by all 5 regions. Another criterion, the typology, is also used by all regions, but
this criterion is not applied in the same manner in
the different regions. Overall, all regions also use the
minimum size of 10 km² for the catchment area to
be identified as water body. In the three Belgian Regions, the methods used to delineate the water bodies are similar to a large extent.
There are noticeably few water bodies in the French
part of the IRBD whereas the French part represents
the largest region of the district. The reason for the
23
Walloon Region
BCR
1. Brook with steep slope
1. Small brook
2. Brook with medium slope
2. Large river
3. River with medium slope
4. Large river with gentle slope
France
1. Small watercourse Flandres intérieures
2. Small watercourse Thiérache
3. Small watercourse Boulonnais
4. Small watercourse Auréole crétacé
5. Small watercourse Moëres
6. Small watercourse Douai-Condé
7. Small watercourse Haute NormandiePicardie
8. Medium-sized watercourse Flandres
intérieures
9. Medium-sized watercourse Douai-Condé
10. Medium-sized watercourse Auréole
crétacé
11. Medium-sized watercourse Haute
Normandie-Picardie
Table 8 : River types defined per region, present in the Scheldt IRBD
Flemish Region
1. Small brook
2. Small brook Kempen
3. Large brook
4. Large brook Kempen
5. Small river
6. Large river
7. Polder watercourse
Netherlands
1. Slow flowing middle
course / lower course
on sand
2
Rivers
few water bodies in France is that the French partner
has delineated the water bodies taking into account a
technical restriction (hydrographical zones of the thematic cartographic database Carthage, that already
existed before the entering into force of the WFD).
In the Dutch part too, only few river water bodies
were delineated. Indeed, here, the major part of fresh
surface water was included in the lake category. The
large number of water bodies in the Flemish Region
is due to the strict compliance with the types, subbasin boundaries, nodes and protected areas when
delineating the water bodies.
All partners have indicated that they would adjust the
delineation of the water bodies further in the future.
Within the international Scheldt river basin district,
there are a number of watercourses that lie across
national/regional borders. These transboundary watercourses require special attuning between the regions concerned.
Each region used the regional or national border
as boundary to delineate the water bodies, so that,
within the Scheldt IRBD, there are no transboundary
water bodies as such.
For certain transboundary watercourses, bilateral
comparisons were made. Table 10 gives an overview
of the relevant transboundary watercourses within
the Scheldt IRBD. It must be noted that part of the
Scheldt on Flemish territory (beyond Ghent) and the
complete Scheldt on Dutch territory belongs to the
transitional water category and that the other watercourses mentioned in the Netherlands are all categorized as lakes.
In the Scheldt IRBD, we have in all 41 transboundary watercourses. Only the Scheldt as such crosses
3 borders (France-Wallonia, Wallonia-Flanders and
Flanders-Netherlands). Five watercourses cross 2
borders: the Leie, the Zwarte Spierebeek and the
Spierekanaal cross the French-Walloon and the Walloon-Flemish border, the Zenne and the Sea canal
Brussels-Scheldt/Canal Brussels-Charleroi cross the
Walloon-Flemish and the Brussels-Flemish border.
The other 35 watercourses cross only one national/
regional border (French-Walloon, French-Flemish,
Walloon-Flemish, Brussels-Flemish or Flemish-Dutch
border).
Table 10 also shows that 93% of the selected transboundary watercourses run through the Flemish Region at the centre of the IRBD. About half flows partly
on Walloon territory and approximately one third on
French territory. Only a quarter of the transboundary
watercourses are located on Dutch territory.
25
II.
Surface water characterization
Table 9 : Criteria used to delineate the river water bodies and the number of water bodies per region
Delineation
steps WB
pursuant to
guidance
document
Step 1:
Categories
France
Walloon
Region
BCR
Flemish
Region
Netherlands
Used
Used
Used
Used
Used
Step 2:
Typology
Used
Used
(Mix of hydroecoregions and
size of the water
bodies)
Used
Used
Used
Step 3:
Physical
characteristics
Strahler order
Length
watercourse
Strahler order
Length
watercourse
Nodes
Step 4:
Other criteria
SAGE
circumference
Sub-basin
limits
Limits
management
plans
Protected areas
(DW, BD, HD)*
Protected areas
(HD, BD, F&S)*
Fish stock
Ecological status
Hydromorphology
Hydromorphology
Load
Step 5:
Heavily modified
nature
Used
53
Used
To be carried
out
Number of river water bodies in the Scheldt IRBD
78
3
32812
Used
3
*DW=drinking water; BD=Bird Directive; HD=Habitat Directive; F&S=fish & shellfish water
2.3 Reference conditions
As the activities for the establishment of type-specific reference conditions for rivers has not been
completed yet for any region, it is impossible to give
a general overview for the river basin district. Most
regions, however, have worked out a number of ecological quality ratios.
Table 11 gives an overview of the existing ecological quality ratios per region and per biological quality
element. It also indicates whether or not reference
conditions have already been established for them.
This table is a snapshot and describes the situation in
June 2004. A description of the methods used to obtain the EQR’s is given in the thematic report “Fresh
surface water”.
26
In table 11, the +/- indicates to what extent the methods used are conformant to the WFD: “+” means that
the method and the corresponding relation to the reference status has been completed or is being worked
out, “-” means that the existing methods still need to
be adjusted to the requirements of the WFD, using
the guidance documents, and finally, “Ø” means that
no method has been developed yet to determine the
EQR, but that studies are ongoing.
The description of the reference conditions in the
specific context of the Scheldt river basin district is
a general problem, as we suspect that there are only
very few locations left that correspond to reference
statuses (undisturbed by human activities) in this river basin district, because many surface waters have
changed dramatically or are even artificially.
2
Rivers
Table 10 : Transboundary watercourses in the Scheldt IRBD
Watercourse
Haine
Grand Courant
Grande Honnelle - Hogneau
Canal Dunkerque-Veurne-Nieuwpoort
Bergenvaart
IJzer
Leie
Gaversebeek
Heidebeek
Vleterbeek
Houtgracht
Zwarte Spierebeek
Spierekanaal
Molenbeek
Canal Ieper-Komen
La Haute Planche
Douvebeek
Grote Spiere(beek)-FabrieksbeekBondillebeek
Scheldt
Nethen-Molenbeek
Mark
Paanhuisbeek
Zenne
Kleine Gete
Grote Gete
Sea canal Brussels-Scheldt/
Canal Brussels-Charleroi
Rhosnes
Laan
Dijle
Dender
Schoorbroekbeek
Woluwe
Damse Vaart/Canal Bruges-Sluis
Leopold canal/Isabella canal
Canal Ghent-Terneuzen
Otheensche kreek
Zoute vaart
Moerspuitse watergang
Oudenburgse sluis/Langelede
Pieters van Endenvaart
Antwerps kanaalpand (Scheldt-Rhine link)
France
x
x
x
x
x
x
x
x
x
x
x
x
x
x
From the summary comparison of the biological assessment methods and related suggestions for classification, put forward by the regions, it appears that
the establishment of reference conditions per type is
first of all, for most regions, the result of the interaction between the input of methodological studies on
Walloon
Region
x
x
x
BCR
Flemish
Region
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Netherlands
x
x
x
x
x
x
x
x
x
x
the one hand and the knowledge of experts on the
other hand.
Then, the reference conditions will be measured in
reference sites for those types for which they are
available.
27
II.
Surface water characterization
As the development of methods by the partners
hasn’t progressed enough yet, a thorough comparison is still impossible.
On European level, an intercalibration exercise is ongoing aimed at enabling a comparison between the
classification used by the different member states to
determine the ecological status.
This exercise is coordinated by the European Commission and first of all consists in establishing an intercalibration network containing locations in all existing
types of surface water bodies. Here, ‘types’ refers to
the typology developed at European level.
In this intercalibration register (provisional version
of 24/5/2004), the following points, located in the
Scheldt IRBD, have been included for the river category:
• type R-C1: 36BE Burggravenstroom 1, 37BE IJsse,
38BE Kleine Nete 2, 52BE Grande Honnelle
• type R-C4: 43BE Grote Nete 1, 44BE IJzer, 45BE
IJzer 1, 46BE Kleine Nete 1, 47BE Laan
• type R-C6: 390FR Aa-Wizernes, 389FR Liane-Hesdigneul, 424FR Hem-Recques
Because of the lack of “natural” water bodies on its
territory, the Brussels Capital Region has not put any
points in the intercalibration register.
In a next stage, the monitoring systems of the member states will be applied on the selected intercalibration points that are relevant for the member state
concerned and the results of this exercise will be used
to determine the values of the class boundaries in the
monitoring system.
Table 11 : Overview of the existing calculation methods for ecological quality ratios (EQR) for rivers per region
Biological quality
element
Benthic invertebrate
fauna
Macrophytes
Phytobenthos
Fish fauna
Phytoplankton
France
IBGN
Walloon
Region
IBGN
BCR
Flemish Region
Netherlands
Ø
Revised BBI
Criterion macrofauna
-
+
IBMR
IBD
+
Ø
Ø
IPS
Ø
+
IPR
+
Ø
IBIP
Ø
Ø
Ø
+
MAFWAT
+
IBD
IPS
(SLAD)
(TDI)
IBI
Ø
Criterion
macrophytes and
phytobenthos
+
Criterion fish
Not applicable
IBGN=Indice Biologique Global Normalisé; BBI=Belgische Biotische Index; IBMR=Indice Biologique Macrophytique en Rivière;
IBD=Indice Biologique Diatomées; MAFWAT=Multi-metric Method for Macrophytes in Watercourses; IPS=Indice de Polluo-Sensibilité;
SLAD=Sladeçek; TDI=Trophic Diatom Index; IPR=Indice Poisson Rivière; IBI=Index voor Biotische Integriteit; IBIP=Indice Biologique
d’Intégrité Piscicole
28
2
Rivers
2.4 Current quality
Parameter
2.4.1
Measurements in the field
Temperature
°C
pH
u.pH
Conductivity at 25°C
µS/cm
O2 (dissolved oxygen)
% and mg/l
2.4.1.1
Existing monitoring networks
Homogeneous monitoring network
The quality of the Scheldt water is followed-up in a
harmonized manner through the homogeneous monitoring network that was put into action by the parties
within the framework of their cooperation within the
International Scheldt Commission.
This monitoring network is operational since 1 January 1998 and has the following starting points:
• Comparability of the measurements for a single
parameter:
from sampling to analysis, the same protocols are
followed strictly and are assessed regularly.
• Cooperation principle:
each party has its own laboratory that carries out
the analysis of samples taken in its own measuring
points. The results are given to the French partner,
who includes them in a database.
• Synchronisation principle:
the samplings take place every four weeks, on the
same day, and every three years for the biological
parameter.
• Transparency principle:
everyone has access to all data of the homogeneous monitoring net.
Currently, the homogeneous monitoring network consists of 14 sampling sites, all located on the Scheldt.
These sampling sites are partly located in the “river”
category and partly in the “transitional water” category. The boundary between both categories is located at the Gentbrugge lock near Ghent. This is the
place up to which the tidal action has an effect.
Seven sampling sites are located in the first category (numbers 10, 20, 30, 40, 50, 60 and 70) and
the seven others are located in the second category
(numbers 80, 90, 95, 100, 110, 120 and 130). Three
of the seven transitional water sites are located in
the freshwater tidal area (80, 90 and 95), while in
the four other locations, the influence of salt water is
determining (100, 110, 120 and 130). Map 7 shows
the location of these sampling sites.
Currently, the homogeneous monitoring network of
the Scheldt covers 32 parameters. From the samples
taken in the homogeneous network, 28 parameters
are analysed. During sampling, there are four additional measurements in the field. The table below
gives an overview of these parameters and of the unit
in which the test results are expressed.
Analyses
NO2- (nitrite)
NO3- (nitrate)
NH3 (ammonia)
NH4+ (ammonium)
N-Kjeldahl (Kjeldahl nitrogen)
N-total (total nitrogen)
P-total (total phosphorus)
Ortho-PO43- (orthophosphate)
Cl- (chloride)
SO42- (sulphate)
SS (suspended solids)
BOD5 (Biochemical Oxygen Demand)
COD (Chemical Oxygen Demand)
Chlorophyll-a
Biological index**
Cd (cadmium)*
Cu (copper)
Zn (zinc)
Atrazine*
Simazine*
Lindane*
Diuron*
Fluoranthene*
Benzo(b)fluoranthene*
Benzo(k)fluoranthene*
Benzo(a)pyrene*
Benzo(ghi)perylene*
Indeno(123cd)pyrene*
Unit
mgN/l
mgN/l
mgN/l
mgN/l
mgN/l
mgN/l
mgP/l
mgP/l
mg/l
mg/l
mg/l
mgO2/l
mgO2/l
µg/l
score
µg/l
µg/l
µg/l
µg/l
µg/l
µg/l
µg/l
µg/l
µg/l
µg/l
µg/l
µg/l
µg/l
*Priority substances pursuant to Annex X of the WFD
**Invertebrate index, assessed every 3 years, only in fresh
surface water
2.4.1.2
Regional monitoring networks
In addition to the homogeneous monitoring network, many other monitoring networks are used in
the Scheldt IRBD, which are the responsibility of the
riparian regions. These monitoring networks will need
to be adapted according to the specific monitoring
obligations imposed by the WFD (art. 8) by the end
of 2006.
All regions now have a region-wide physico-chemical
monitoring network. This is not the case yet for all
biological quality elements. Table 12 gives an overview of the existing biological monitoring networks
per region. There is also an indication whether or not
these monitoring networks already meet the 2006
29
Map 7 : Sampling sites of the homogeneous monitoring network (2001)
II.
30
Surface water characterization
2
Rivers
Table 12 : Overview of the existing biological monitoring networks per region
Macroinvertebrates
p-c
e
yes
K
France
yes
Fish
p-c
K
Walloon Region
K
BCR
L
Flemish Region
K
yes
K
Netherlands
J
no
L
Monitoring network type
Phytobenthos
Macrophytes
(diatoms)
e
p-c
e
p-c
e
no
yes
K
L
L
K
L
yes
requirements of the WFD and whether these already
cover the whole region concerned.
In table 12, columns “p-c” indicate whether the type
of monitoring network concerned is already present,
and if so, whether it already meets the provisions
of the WFD to be met by 2006 (conformity). Here,
“J” indicates that a monitoring network exists for the
element concerned and that it already meets the requirements of the WFD for 2006, “K” means that the
monitoring network exists, but that it doesn’t meet
the requirements of the WFD to be met by 2006 and
“L” means that there is no monitoring network yet
for the element concerned. Columns “e” indicate
whether the existing network covers the entire region or not.
As shown in table 12, only the Netherlands have a
monitoring network for macrophytes and for phytoplankton and, until now, the monitoring networks for
macro-invertebrates are the most developed. The
intercalibration exercise described earlier will be applied to the above monitoring networks in order to
test the comparability of the class boundaries established by the different member states.
2.4.2
2.4.2.1
Quality of the watercourses
The Scheldt
An analysis of the monitoring results of the homogeneous monitoring network for the period 1998-2002
is included in the “Report on the water quality of the
Scheldt” by the ISC. This report concludes that an
improvement has been observed for many parameters over the years. However, according to the report, these observed improvements can mainly be
attributed to an increased drainage in 2001 and 2002
as a result of heavy rainfall. It also concludes that
the considerable improvement for nitrogen (total and
ammoniacal nitrogen) is due to the commissioning of
adequate water treatment plants and to the reduction of certain industrial discharges.
yes
Phytoplankton
p-c
L
L
L
L
L
L
L
L
L
L
J
no
J
e
no
From the results of two monitoring campaigns for biological elements (diatoms in 2000 and benthic macro-invertebrates in 2002), we can also conclude that
the biological water quality is moderate to bad.
The evolution of the water quality in the Scheldt still
rests on a very unstable balance that is influenced by
natural factors (such as rainfall).
2.4.2.2
Transboundary watercourses
For the description of the current quality of watercourses that cross or form borders between regions/countries, the data for the year 2002 (2000
for France) produced by the monitoring networks described under § 2.4.1 are used and in 5 transboundary watercourses (Zenne, Scheldt F-W, Dender, IJzer
and Scheldt VL-NL), two points on both sides of the
border have been selected each time.
For the selected monitoring points, the following
parameters were compared: dissolved oxygen, biochemical oxygen demand, chemical oxygen demand,
ammonium, Kjeldahl nitrogen, nitrate, total phosphate, copper, zinc, chromium, arsenic, cadmium,
mercury, lead and nickel (the last 4 are priority substances pursuant to Decision N° 2455/2001/EC).
Whenever available, data concerning biological quality elements were compared for a larger number of
transboundary watercourses.
Then, the monitoring results collected for the physico-chemical parameters were tested against the
standards existing in the different riparian regions.
For the Flemish Region, the Walloon Region and the
BCR, these are the basic quality standards, for the
Netherlands the standards from the Fourth Note on
Water Management. For France, the results were
tested against the threshold values for the level ‘good
status’ in the ‘Système d’Evaluation de la Qualité de
l’eau’ (SEQ-Eau). For the Walloon Region, a second
test was carried out (second column for Dender W
and Scheldt W – see table 13) on the basis of a revised and provisional version of the SEQ-Eau.
31
II.
Surface water characterization
The monitoring results for the 10 selected monitoring
points, details concerning the standards used and the
results of the test against the standards can be found
in the thematic report “Fresh surface water”.
The available biological data were assessed by the
different partners on the basis of expert judgement.
For the Flemish Region, only data about macro-invertebrates were available (and a few data for fish).
For the Walloon Region, the available data concerned
macro-invertebrates and diatoms. For the Netherlands, data about macro-invertebrates, macrophytes,
phytoplankton and fish were used. For France, only
data for macro-invertebrates were added. The BCR
has no biological data available and was not included
in the comparison.
The results of this assessment, as well as an evaluation across the different biological quality elements,
can be found in the thematic report “Fresh surface
water”.
For the global assessment, the principle ‘one out, all
out’ was applied, i.e. one unsatisfactory score for one
single biological quality element is enough to give an
unsatisfactory final assessment. Finally, the assessments made by the different partners were combined
with each other to form a provisional final assessment for the transboundary watercourses.
A summary of the results of the above exercise can
be found in table 13 for 4 of the 5 transboundary
watercourses for which physico-chemical data were
collected. The Scheldt, where it crosses the border
between Flanders and the Netherlands, was not included in the table because, at that point, it belongs
to the category transitional waters (see § 4).
Observation regarding priority substances:
The drawing up of quality standards for the 33 priority substances listed in Annex X to the WFD has not
been completed yet at European level (a draft daughter directive is expected in 2005). Therefore, it was
not possible to carry out an analysis on this theme.
In table 13, the 4 priority substances for which monitoring data are available for the watercourses concerned (Cd, Hg, Pb and Ni) are therefore considered
as elements of the ‘physico-chemical quality’ (part
inorganic micro-pollutants) for now.
In table 13, the following definitions apply:
• “?” indicates that no assessment can be made because no data are available;
• for the biological quality, red indicates that, on the
basis of the available data, the quality is judged
‘moderate’ or lower (this means ‘poor’ or ‘bad’) and
green indicates that the quality is ‘good’ or higher
(this means ‘high’) (= test against the threshold
value for the ‘good biological status’);
• for the physico-chemical quality, red indicates
that, for the group of parameters concerned (oxygen balance, nutrients or inorganic micro-pollutants) and on the basis of the available data, at
least one parameter exceeds the standard used in
the country concerned; in this case, we indicate for
which parameter the standard is exceeded. Green
indicates that the standard is exceeded for none of
the parameters.
This exercise, whereby the current standards of the
regions were also compared, made it possible to draw
the following conclusions from the physico-chemical
parameters:
• overall, the assessment of the ‘good status’ that
is based on the SEQ-Eau (used in France and the
Walloon Region) is the strictest and often produces a provisional assessment of ‘good status
not achieved’. The Dutch standards are stricter
for nickel and dissolved oxygen only. The Walloon
and Brussels basic quality standards are the most
flexible. Therefore, it is obvious that the different
standards often produce a different assessment
of the parameters concerned. Should the strictest
standards be applied, then the current quality of
the transboundary watercourses concerned would
be non-conformant for most test parameters;
• sometimes, monitoring results from monitoring
sites that are close to each other, but are monitored by different partners, differ significantly. Especially on the Zenne near the border crossing between the Flemish Region and the BCR. Here, the
values measured in one region are up to five times
32
2
Rivers
Table 13 : Current quality of 4 transboundary rivers, on 8 monitoring points near the national / regional borders
Water body
(monitoring point)
Biological quality
Physicooxygen
chemical
balance
quality
nutrients
Zenne VL
(VMM 347000)
MI*
BOD, COD, O2
Zenne BR
(Viangros)
?
COD
NH4+, Ptot, NKj
NH4+
Scheldt F
(AEAP 019000)
?
Scheldt W**
(DGRNE 360)
MI, dialoms
inorganic
micropollutants
Dender W**
(DGRNE 1281)
MI, diatoms
COD
NH4+, Ptot,
NKj
Cr, Cu, Zn,
Pb, Cd
Dender VL
(VMM 511000)
MI
COD
Ptot
First assessment of the
ecological status
Water body
(monitoring point)
Biological quality
Physicooxygen
chemical
balance
quality
nutrients
inorganic
micropollutants
NH4+, Ptot, NKj,
NO3?
NH4+, Ptot,
NKj
Cu, Zn,
Pb, Cd
IJzer F
(AEAP 89000)
MI
IJzer VL
(VMM 916000)
MI
COD, O2
Ptot, NKj, NO3?
First assessment of the
ecological status
*MI = macro-invertebrates
**For the Walloon Region, the results were tested against the basic quality standard (left-hand column) and against the threshold values
for ‘good status’ of the revised SEQ Eau (‘good biological suitability’ – right-hand column).
higher than in the other region. For some parameters, these differences also produce a different
assessment, for others, the test result is identical.
Of course, these findings don’t make it easy to judge
the quality of the monitored watercourses. Both the
variations in monitoring results and the different assessment systems can result in different conclusions
regarding the water status. These results could indicate the necessity to investigate this issue in further detail, in order to establish together a way in
which assessments could be carried out in the future. The intercalibration exercise provided for by the
WFD must meet this objective. The experiences with
the homogeneous monitoring network on the Scheldt
can contribute to the harmonization of the monitoring methods with a view to making the assessments
comparable.
However, here we must take into account the fact
that these assessments were carried out on the basis of evaluation systems dating back to before the
entering into force of the WFD, and this restricts the
importance of the conclusions with respect to the implementation of the WFD.
Within the framework of the Scaldit activities, we
haven’t succeeded yet in drawing up a list of the relevant substances for the Scheldt. This will be done
in 2005.
Regarding the biological quality, the assessment
revealed that only a few of the approximately fifty
monitoring sites considered achieve good biological
quality.
33
II.
Surface water characterization
3
Lakes
3.1 Typology
To establish a typology for lakes, the Netherlands,
France and the Flemish Region have used system B.
There are no lakes larger than 50 ha in the Brussels
part and in the Walloon part of the Scheldt IRBD. This
is the lower size limit for lakes provided for by the
WFD. Therefore, no typology was developed for these
parts of the river basin district.
Given the great difference in factors used per region,
no common types could be developed. Table 14 gives
an overview per region of the descriptors used for the
typification of lakes. For the Flemish Region, the typology was developed on a regional level, for France
and the Netherlands on a national level.
By applying the descriptors in table 14, it was possible to define a number of types per region. The types
that are found in the Scheldt IRBD are listed in table
15.
Table 14 : Descriptors used for the typification of lakes per region (there are no lakes in the Brussels and Walloon part of the river basin district)
France
Flemish Region
Area:
Area:
> 50 ha
> 50 ha
Depth:
<3m
3 – 15 m
Netherlands
Salinity:
0 – 0.3 g Cl/l
0.3 – 3 g Cl/l
3 – 10 g Cl/l
> 10 g Cl/l
Form, geology:
Non-linear or linear, > 50% siliceous
Area/Width:
< 50 ha
50 – 10,000 ha
Wider than or narrower than 8 m
Depth:
< or > 3 m deep (criterion only applicable if < 0.3 g Cl/l)
Buffer capacity:
weakly buffered 0.1 – 1 meq/l
buffered 1 – 4 meq/l
Table 15 : Defined lake types per region, present in the Scheldt IRBD
France
1. Lakes formed by excavation, in
hard rock, not drainable
2. Shallow lake, obtained by
excavation, in the high
water bed of a watercourse,
connected with the aquifer, Lshaped, without thermocline
3. Lake in plain or medium
highland, on impenetrable
substrate, fed by springs,
temporary watercourses or
class 1 or 2 watercourse,
usually not drained,
but controlled hydraulic
management
34
Flemish Region
1. Moderatly ion rich, alkaline
waters
2. Large, deep, alkaline waters
Netherlands
1. Buffered ditches
2. Weakly buffered ditches
3. Shallow, weakly buffered pools
4. Medium-sized, deep, buffered
lakes
5. Weakly brackish waters
6. Small, brackish to brinish
waters
7. Large, brackish to brinish lakes
Observation: Types 1 and 2 are
the polder watercourses discussed
under § 2.1
3
Table 16 : Number of lake water bodies per region
(there are no lakes in the Brussels and Walloon parts
of the river basin district)
Number of lake water
bodies
3
14
64
81
France
Flemish Region
Netherlands
DISTRICT
Lakes
lineate the lake water bodies. For the Dutch part of
the Scheldt IRBD, additional criteria must be used, as
the Dutch lake water bodies are partly linear waters
and therefore not lakes in the usual sense. Here, the
existing classification into water systems (based on
the hydrological characteristics) was used in addition
to the geographical characteristics (such as dykes,
dams, breakwaters, locks and other gates).
Table 16 gives an overview of the number of delineated lake water bodies in the different parts of the
river basin district.
Because it is very difficult to develop a typology for
lakes in a simple and ecologically consistent manner,
and because it seems much more dependent on local
criteria, it was practically impossible to compare the
lake types from the different regions.
As mentioned under § 3.1, the lakes in the IRBD of
the Scheldt have hardly any common characteristics.
The lakes are also so different, that comparison offers
little added value (France: artificial freshwater lakes
> 50 ha; Flemish Region: freshwater lakes, mostly
artificial > 50 ha; Walloon Region and BCR: no lakes;
Netherlands: brinish/brackish lakes, whereby those
< 50 ha have also been taken into account).
For lakes, type-specific reference conditions must be
worked out, just like for rivers.
The activities regarding the establishment of reference conditions for lakes are less advanced than for
rivers, and we can’t give a general overview for the
river basin district either. Some regions, however,
have developed a number of ecological quality ratios.
Moreover, in the Scheldt IRBD, there are no transboundary lakes. Bilateral attuning between the Flemish Region and the Netherlands will be needed, however, for a number of transboundary canals, the ecological potential of which will probably be compared
to a lake type: Canal Ghent-Terneuzen, Scheldt-Rhine
link and Canal Bruges-Sluis.
3.2 Water bodies
For the French and Flemish part of the IRBD, the
physical boundary was taken as sole criterion to de-
Table 17 : Overview of the existing ecological quality
ratios (EQR) for lakes per region
Biological
quality
element
Benthic invertebrate
fauna
Macrophytes
France
Flemish
Region
Netherlands
Ø
Ø
Ø
Phytobenthos
Fish fauna
Phytoplankton
Ø
MAFST
(R for 1
type)
Ø
Criterion
macro-fauna
(R)
Criterion
macrophytes
and
phytobenthos
(R)
Ø
Ø
Ø
Ø
Criterion fish
Criterion
phytoplankton
3.3 Reference conditions
Table 17 gives an overview of the existing ecological
quality ratios per region and per biological quality element, and indicates whether or not reference conditions have been established for them. A description of
the methods used to obtain the EQR’s can be found in
the thematic report “Fresh surface water”.
In table 17, “R” means that for the biological quality element concerned type-specific reference conditions have already been developed, “Ø” means that
no method exists yet to determine the EQR.
As shown in table 17, the Dutch partner is the only
one who has progressed considerably in working out
ecological quality ratios for lakes. A large part of the
fresh surface water in the Dutch part of the IRBD is
also categorized as lake. Therefore, the lake category
has a much more prominent presence in the Dutch
part and has a much greater importance than in the
other parts of the river basin district.
In the European intercalibration register (provisional
version of 24/5/2004), the following points located
in the Scheldt IRBD have been included in the lake
category:
• type L-CE1: 18BE Gavers – Harelbeke
• type L-CE2: 17BE Blokkersdijk, 20BE Torfbroek
– Berg
• type L-CE3: 19BE Groot Schietveld – Wuustwezel
MAFST=multimetric method for macrophytes in standing waters
35
II.
Surface water characterization
4
Transitional waters
4.1 Typology
All regions in the Scheldt river basin district opted
for system B to establish a typology for transitional
waters.
The cooperation within Scaldit has resulted in a common transnational typification of transitional waters
in the Scheldt river basin district, based on the European recommendations. The water types were established in the way proposed by the CIS guidance
document “Typology, reference conditions and classification systems for transitional and coastal waters”,
§ 3.5.
The determining physical parameters used for the
typification of transitional water are the following:
• salinity;
• tidal range;
• composition of the substrate;
• velocity.
The application of these descriptors has resulted in
the identification of five types of transitional waters
for the entire Scheldt IRBD. Table 18 gives an overview of the five defined types.
Table 18 : Defined types of transitional water in the
Scheldt IRBD
Type
Type 1
Type 2
Type 3
Type 4*
Type 5*
Type description
macro-tidal, mixed sediment, medium
to high velocity (estuary)
meso-tidal, silt and sandy sediment,
high velocity (estuary)
macro-tidal, silt and sandy sediment,
low velocity (estuary)
macro-tidal, silt and sandy sediment,
low velocity (port)
macro-tidal, silt and sandy sediment,
medium to high velocity (port)
*In France, the typology was simplified at the national level. This
resulted in the merger of (local) types 4 and 5 into a single type
at national level: “large, macro-tidal ports”.
3.4 Current quality
A lot less information is available about the current
quality of lake water bodies than about the river water bodies. In France and in the Flemish Region, no
permanent monitoring points in lakes have been included in the existing monitoring networks, and only
results of studies are available. As a result it is difficult
to judge the current quality of lake water bodies.
Monitoring results are only available for the Dutch
part of the Scheldt IRBD, where almost all fresh surface waters are considered as lakes. For this, we refer
to the Dutch art. 5 report.
36
4.2 Water bodies
Before we can apply the typology, the categories to
which the water bodies belong must be established.
This is done by establishing boundaries in the surface
water between transitional water, coastal water and
freshwater, on the basis of several criteria.
The boundary between categories coastal water and
transitional water can be determined in several ways,
i.e. on the basis of:
• European or national legislation;
• the salt content (salinity);
• physical or geographical characteristics.
4
Transitional waters
Table 20 : Delineated transitional water bodies per region.
Delineated transitional water body
France
Flemish Region
Netherlands
1.
2.
3.
4.
1.
2.
3.
4.
5.
1.
Somme (estuary) (TWSF1)*
Dunkerque (port) (TWSFDK)*
Calais (port) (TWSFCL)*
Boulogne (port) (TWSFBL)*
IJzer (estuary) (TWSB2)*
Scheldt and tidal linked tributaries
(cluster) (TWSB1)*
Zeebrugge (port)
Blankenberge (port)
Ostend (port)
Westerschelde (TWSN1)*
Type of water body
(see table 18)
type 3
type 4
type 4
type 5
type 2
type 1
not typified (artificial)
not typified (artificial)
not typified (artificial)
type 1
*Code used for the water body
For the boundary between fresh surface water and
transitional water, we can use either the salt/fresh
boundary or the tidal boundary, depending on the
boundary that best suits the local conditions.
We can conclude that all regions in the river basin district were able, with the boundaries or starting points
put forward by the WFD, to establish the boundaries
between coastal and transitional waters. Here, we
must indicate that locks and differentiations provided for in the national legislations were also used as
boundary between river and transitional water. Table
19 shows an overview of the boundaries used.
Ten transitional water bodies were identified in the
Scheldt river basin district. Table 20 gives, per region, which transitional water bodies were delineated
and to which type these water bodies belong.
In the Scheldt IRBD, there is one transitional water
with a transboundary nature, i.e. the transitional water Scheldt (TWSB1) – Westerschelde (TWSN1). How-
Table 19 : Boundaries used to delineate coastal and
transitional water bodies
Boundary between
Coastal water and
transitional water
Transitional water and
fresh surface water
Coastal waters
Transitional water and
land
Coastal water and land
Coastal water and fresh
surface water
Criterion used
Salinity, hydrology
or physiographical
characteristic
Locks, tidal limits,
national legislation
Typology, flood barrier
Dykes
High water line
National legislation,
physiographical
characteristic
ever, the national border has been used to delineate
the water bodies, so that, within the Scheldt IRBD,
they are considered as ‘neighbouring water bodies of
the same type’, instead of transboundary water bodies. Here, we must also indicate that the transitional
water body ‘Scheldt and tidal linked tributaries’ on the
Flemish territory, that has been clustered for Scaldit
purposes, in fact consists of several water bodies.
We can conclude that all transitional waters in the
Scheldt river basin district are delineated and typified
in an unequivocal, comparable manner. For the identified neighbouring water bodies of the same type, we
will then aim at transnational agreements regarding
the objectives and measures to be taken.
4.3 Reference conditions
It is currently impossible to compare the available
references for transitional waters in the Scheldt river
basin district. This is due to the different methods
used in the different countries to establish the reference conditions. It was impossible to harmonize the
methods because this requires thorough scientific
consultation beyond the scope of Scaldit.
There are good opportunities to learn from each other’s approach during further cooperation and to enrich
the national debate in order to reach a comparable
description of the reference conditions. The search
for coherence is important, a/o, for the neighbouring
water bodies of the same type, like the Scheldt estuary. First of all, the national methods are based on
the following elements:
• In the Netherlands, provisional reference conditions for transitional waters and a classification
(classes ranging from ‘high status’ to ‘bad status’) per biological quality element have been established. This is based on expert judgement and
available (historic) information on the quality ele37
II.
Surface water characterization
Table 21 : Current ecological quality of the transitional water bodies
Water body
Biological quality
Physicochemical
quality
Somme
(estuary)
Boulogne
(port)
Calais
(port)
Duinkerke
(port)
(F)
phytoplankton
(F)
(for 6070% of the
territory)
(F)
benthic
fauna (for
70% of the
territory)
(F)
benthic
fauna,
macro-algae
oxygen
balance
nutrients
micropollutants
O2
N
Cd, Hg, Zn,
PAH
PAH
Scheldt
and tidal
linked
tributaries
(VL)
phytoplankton,
macrofauna, fish
Westerschelde
(NL)
phytoplankton, macrofauna, macro-algae,
fish
T, O2
susp.
matter, O2
N, P
N, P
N, P
Cd, Pb, Zn,
Hg, PAH
Zn, Cd, PAH
Zn, Cu
First estimate of the
ecological status
: quality ‘close to undisturbed conditions’
: quality ‘remote from undisturbed conditions’. In the cells of the table, we indicated which quality element or which substance
caused the water body to be remote from the undisturbed condition.
ments. No references have been described yet for
the physico-chemical quality elements. For now,
the national standards for these elements (substances) are used. There are no natural reference
locations for transitional water in the Dutch part of
the Scheldt river basin district.
• The Flemish Region has developed provisional reference conditions and a classification system in
five classes to describe the biological quality elements. Expert judgement, historic information and
a scientific approach of the working of an estuary
system were used to set up the classification. No
references have been described yet for the physico-chemical quality elements. There are no natural reference locations for transitional water in the
Flemish part of the Scheldt river basin district.
• As yet, France doesn’t have any reference conditions or classification system in five classes for the
biological quality elements as prescribed by the
WFD. The ecological quality is assessed through a
simplified approach. On the basis of expert judgement, completed with data where these are available, it is assessed whether the current quality is
‘close’ or ‘remote’ from undisturbed conditions.
This applies for biological and for physico-chemical
quality elements. For some types of water bodies
and certain biological quality elements, natural locations for transitional water have been identified
38
that reveal a current quality that could match undisturbed conditions according to experts.
In the European intercalibration register (provisional
version of 24/5/2004), the following point has been
registered for the category transitional water in the
Scheldt IRBD:
• type TW-NEA11: 99NL Westerschelde
4.4 Current quality
Strictly speaking, a transnational comparison of the
current ecological and chemical status of the water
bodies is impossible for now. For the chemical status in the sense of the WFD, this is due to (1) the
different monitoring and analysis methods used for
monitoring in the different countries and (2) the lack
of environmental quality standards for WFD Annex
IX and X substances. For the ecological status in the
sense of the WFD, this isn’t possible either, because
of the different approaches for establishing the reference conditions and the classification.
However, a simplified method was used with a view
to a coordinated description of the current ecological
quality of the water bodies.
It is not possible yet to assess the current quality for
the IJzer estuary, because there is no monitoring.
4
4.4.1
Transitional waters
Ecological quality
Within the project, a transnational, simplified comparison of the current ecological quality has been
carried out. Here, the French approach was followed
to describe the quality. For the biological quality elements, the Flemish Region and the Netherlands have
done this by making the classification ‘good’ (and
higher) equivalent to the (French) quality ‘close to
undisturbed conditions’ and the classifications ‘moderate’ and lower to the (French) quality ‘remote from
undisturbed conditions’.
For the physico-chemical quality elements, the Flemish Region and the Netherlands have done this by
establishing that, if the national standard of a physico-chemical element (substance) is exceeded, this is
equivalent to the French quality ‘remote from undisturbed conditions’.
The result of this comparison is presented in table 21.
We can conclude that none of the transitional waters
in the Scheldt river basin district are close to undisturbed conditions. In almost all transitional waters,
the biological quality elements and the chemical elements are ‘remote from undisturbed conditions’. For
the biological quality, in general, the quality of phytoplankton and of the benthic invertebrate fauna is
insufficient. For the chemical quality elements, heavy
metals and PAH’s are usually a problem, as well as
nutrients.
4.4.2
Chemical quality
Pending the establishment by the EC of environmental quality standards for WFD Annex IX and Annex
X substances, France and the Flemish Region have
made no assessment yet of the chemical status of the
transitional waters in the sense of the WFD.
The Netherlands has carried out a provisional assessment of the current chemical status. The Westerschelde is not in a good chemical status. In the
assessment, the Netherlands used the provisional
standards drawn up by the Fraunhofer Institute. In
the Westerschelde, the standards for a number of
substances are exceeded. Problem substances in the
Westerschelde are nickel and TBT.
Strictly speaking, for the Flemish Region and the
Netherlands, due to the presence of a homogeneous
monitoring network, a transnational comparison of
the chemical status could be possible.
39
II.
Surface water characterization
5
Coastal waters
Table 23 : Delineated coastal water bodies per region
Delineated coastal
water bodies
5.1 Typology
All regions in the Scheldt river basin district have
opted for system B to establish a typology for coastal
waters.
France
The cooperation within Scaldit has resulted in a common transnational typification of coastal waters in the
Scheldt river basin district, based on the European
recommendations. The establishment of the water
types was done in the way presented in the CIS guidance document “Typology, reference conditions and
classification systems for transitional and coastal waters”, § 3.5.
The determining physical parameters used for the
typification of coastal waters are the following:
• salinity;
• tidal range;
• wave action;
• composition of the substrate.
The application of these descriptors resulted in the
identification of six types of coastal waters. Table 22
gives an overview of the six defined types.
Table 22 : Defined types of coastal water in the
Scheldt IRBD
Type
Type 1
Type 2
Type 3
Type 4*
Type 5*
Type 6
Type description
meso-tidal, polyhaline, very
protected, mixed sediment
meso-tidal, euhaline, unprotected,
sandy
meso-tidal, euhaline, protected,
sandy
macro-tidal, euhaline, medium
unprotected, sandy
macro-tidal, euhaline, medium
unprotected, gravel to pebbles
macro-tidal, euhaline, medium
unprotected, pebbles to rock
*In France, the typology was simplified on a national level. This
results in the regrouping of the (local) types 4 and 5 in a single
type at national level: “macro-tidal coast, mainly sand”
5.2 Water bodies
Eleven coastal water bodies were delineated in the
Scheldt river basin district. The criteria used for delineation are listed in table 19. Table 23 gives, per
region, which coastal water bodies were delineated
and to which type they belong.
40
Belgium
Federal**
Flemish
Region
Netherlands
1. Coast Be-Fr border
to pier at Malo
(CWSF1)*
2. Coast Malo to Cap
Gris Nez (CWSF2)*
3. Coast Cap Gris Nez
to Slack (CWSF3)*
4. Coast Slack to La
Warenne (CWSF4)*
5. Coast La Warenne to
Ault (CWSF5)*
1. Belgian coast
(CWSB1)*
1. The Zwin (VL)
(CWSB2)*
1. The Zwin (NL)
(CWSN3)*
2. Zeeland coast
(CWSN1)*
3. Oosterschelde
(CWSN2)*
4. Canal through ZuidBeveland (CWSN4)*
Type of the
water body
(see table
22)
type 2
type 4
type 6
type 5
type 4
type 2
type 1
type 1
type 2
type 3
type 3
*Code used for the water body
**In Belgium, the Federal State, and not the Regions, is competent for territorial waters, and therefore coastal waters. The
Zwin is an exception, because this is an inlet located on Flemish
territory. Notwithstanding, the category “coastal water” is not
defined pursuant to the Flemish legislation.
In the Scheldt IRBD, there are several transboundary coastal waters. For legal reasons, the national
borders are used as boundary to delineate the water
bodies, so that, within the Scheldt IRBD, they are
considered as ‘neighbouring water bodies of the same
type’ instead of transboundary water bodies. These
are the Zwin (VL) (CWSB2) – Zwin (NL) (CWSN3)
and Zeeland coast (CWSN1) – Belgian coast (CWSB1)
– coast Be-Fr border to pier at Malo (CWSF1). For
these neighbouring water bodies, it is important that
comparable reference conditions and environmental
objectives are defined for the river basin management plan and that measures are attuned.
For the coastal waters in the Scheldt river basin district too, we can conclude that they are delineated
and typified in an unequivocal and comparable manner. In a next stage, the aim for the neighbouring
water bodies will be the establishment of transnational agreements on objectives and measures to be
taken.
5
Coastal waters
Table 24 : Current ecological quality of the coastal water bodies
Water body
Biological quality
Physicochemical
quality
Coast La
Coast
Warenne to
Slack to La
Ault
Warenne
(F)
(F)
phytoplankton phytoplankton
Coast Cap
Gris Nez to
Slack
(F)
phytoplankton
Coast Malo to
Cap Gris Nez
Oosterschelde
(F)
phytoplankton
(NL)
macro-algae
oxygen
balance
nutrients
N
N
N
N, P
micropollutants
PAH, PCB
153, lindane
lindane
PAH
PAH, PCB 153,
lindane
organotin
compounds
First estimate of the
ecological status
: quality ‘close to undisturbed conditions’
: quality ‘remote from undisturbed conditions’. In the cells of the table, we indicated which quality element or which substance
caused the water body to be remote from the undisturbed condition.
5.3 Reference conditions
It is currently impossible to compare the available
references for coastal waters in the Scheldt river basin district. This is due to the different methods used
in the different countries to establish the reference
conditions. Harmonization of these methods was
impossible because this requires thorough scientific
consultation beyond the scope of Scaldit.
There are good opportunities to learn from each other’s approach during further cooperation and to enrich
the national debate in order to reach a comparable
description of the reference conditions. The search
for coherence is important, a/o, for the neighbouring
water bodies of the same type. First of all, the national methods are based on the following elements:
• In the Netherlands, provisional reference conditions for coastal waters and a classification (classes ranging from ‘high status’ to ‘bad status’) per
biological quality element have been established.
This is based on expert judgement and available
(historic) information on the quality elements. No
references have been described yet for the physico-chemical quality elements. For now, the national standards for these elements (substances) are
used. There are no natural reference locations for
coastal water in the Dutch part of the Scheldt river
basin district.
• The Flemish Region and Belgium don’t have any
reference conditions and classification system for
their coastal waters yet. Research in this matter is
ongoing. Relevant activities for defining reference
conditions and the classification systems for coast-
al water are discussed within the framework of the
OSPAR Convention (Convention for the Protection
of the Marine Environment of the North-East Atlantic, 22/09/1992), to which France, Belgium and
the Netherlands are parties.
• As yet, France doesn’t have any reference conditions or classification system in five classes for the
biological quality elements as prescribed by the
WFD. The ecological quality is assessed through a
simplified approach. On the basis of expert judgement, completed with data where these are available, it is assessed whether the current quality is
‘close’ or ‘remote’ from undisturbed conditions.
This applies for biological and for physico-chemical
quality elements. For some types of water bodies
and certain biological quality elements, natural locations for coastal water have been identified that
reveal a current quality that could match undisturbed conditions according to experts.
In the European intercalibration register (provisional version of 24/5/2004), the following point has
been registered for the category coastal water in the
Scheldt IRBD:
• type CW-NEA1: 96NL Schelde Kust
5.4 Current quality
Strictly speaking, a transnational comparison of the
current ecological and chemical status of the water
bodies is impossible for now. For the chemical status in the sense of the WFD, this is due to (1) the
different monitoring and analysis methods used for
monitoring in the different countries and (2) the lack
41
II.
Surface water characterization
Table 25 : Current ecological quality of neighbouring coastal water bodies of the same type (type 2)
Water body
Biological quality
Physicochemical
quality
oxygen
balance
nutrients
micropollutants
Coast Be-Fr border to
pier Malo
(F)
phytoplankton
Belgian Coast
Zeeland Coast
(B)
phytoplankton
(NL)
phytoplankton
N, P
N, P
N, P
PAH, PCB 153
PCB
PCB, organotin
compounds
First estimate of the
ecological status
: quality ‘close to undisturbed conditions’
: quality ‘remote from undisturbed conditions’. In the cells of the table, we indicated which quality element or which substance
caused the water body to be remote from the undisturbed condition.
of environmental quality standards for WFD Annex
IX and X substances. For the ecological status in the
sense of the WFD, this isn’t possible either, because
of the different approaches for establishing the reference conditions and the classification.
However, a simplified method was used with a view
to a coordinated description of the current ecological
quality of the water bodies.
It is not possible yet to assess the current quality for
the Zwin (both NL and VL) and for the Canal through
Zuid Beveland, because no monitoring is carried out.
5.4.1
Ecological quality
Within the project, a transnational, simplified comparison of the current ecological quality has been
carried out. Here, the French approach was followed
to describe the quality. For the biological quality el-
ements, Belgium and the Netherlands have done
this by making the classification ‘good’ (and higher)
equivalent to the (French) quality ‘close to undisturbed conditions’ and the classifications ‘moderate’
and lower to the (French) quality ‘remote from undisturbed conditions’.
For the physico-chemical quality elements, Belgium
and the Netherlands have done this by establishing
that, if the national standard of a physico-chemical
element (substance) is exceeded, this is equivalent
to the French quality ‘remote from undisturbed conditions’. The result of this comparison is presented in
tables 24 and 25.
We can conclude that none of the coastal waters in
the Scheldt river basin district are close to undisturbed conditions. For the biological quality, in general, the quality of phytoplankton is insufficient. For
the chemical quality elements, PCB’s, PAH’s, lindane
and organotin compounds are a problem, as well as
nutrients.
Table 25 shows that the assessment of the different
quality elements in the neighbouring water bodies of
the same type matches. The phytoplankton quality
is insufficient everywhere as a result of Phaeocystis
proliferation. Nitrogen and phosphate are a problem
in all three water bodies. The problem substances
among the micro-pollutants are comparable in most
cases.
5.4.2
Chemical quality
Pending the establishment by the EC of environmental quality standards for WFD Annex IX and Annex X
substances, France and Belgium have made no as42