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Ireland’s Environment 2012
48
Canal Water Quality
The main canal systems (the Royal
and Grand Canals) and sections
of the Shannon-Erne Waterway
have been identified as artificial
water bodies (AWBs) under the
WFD. They are required to achieve
good ecological potential rather
than ecological status. Ecological
potential means that the water body
is managed to achieve the biology
that can be attained given its artificial
nature. For classification purposes,
the ecological potential can be
maximum, good, moderate, poor
or bad. The interim classification of
ecological potential for Irish canals,
based on chemical, biological and
hydromorphological criteria, showed
that 87% of the 332 km surveyed
was at good ecological potential
(Waterways Ireland and Central
Fisheries Board, 2008).
Water-quality monitoring over
the period 2007–2009 indicated
generally good conditions in the
Royal and Grand Canal systems
and in the canalised section of the
Shannon-Erne Waterway (Central
Fisheries Board, 2008 and 2009).
In 2010 and 2011 quality remained
generally in good condition.
Lake Water Quality
In the period 2008–2010, ecological
status was assigned to 208 lakes by
the EPA, representing 981 km
2
of
lake surface water covering 65% of
the total lake surface area in Ireland
(see Table 4.3).
This shows that 97 (46.6%) lakes
were of high or good status with the
majority, 39%, in the latter category.
Ireland ranks very favourably in
a comparison of nutrients and
chlorophyll against other European
countries. Figure 4.6 compares
average concentrations of total
phosphorus, chlorophyll, nitrate
and ammonia in lakes over the
period 2007–2009, which were the
latest dates available at the time of
writing. Ireland has the third lowest
concentrations of total phosphorus;
the 4th lowest concentrations of
chlorophyll and ammonia; and
the 7th lowest concentrations of
nitrate or oxidised nitrogen in this
representative network of lakes.
Figure 4.5
Map showing Main Canal Systems Identified as Artificial
Water Bodies (AWBs) under the Water Framework Directive (WFD).
(Source: Waterways Ireland)
Table 4.3
Lake Water Quality in Ireland – Ecological Status 2008–2010 (Source: EPA)
Ecological Status
Number of Lakes
% of Lakes
Surface Area
(km
2
)
% Area
High
16
7.7
22.1
2.3
Good
81
38.9
412.0
42.0
Moderate
69
33.2
282.3
28.8
Poor
37
17.8
257.2
26.2
Bad
5
2.4
7.4
0.8