On
The WFD also notes that there are uses of water that do not fit
into management schemes which simply take aim in improving the ecological
status of watercourses, namely those ”which adversely affect the status of
water but which are considered essential on their own terms – they are
overriding policy objectives. The key examples are flood protection and
essential drinking water supply, and the problem is dealt with by providing
derogations from the requirement to achieve good status for these cases, so
long as all appropriate mitigation measures are taken. Less clear-cut cases are
navigation and power generation, where the activity is open to alternative
approaches (transport can be switched to land, other
means of power generation can be used). Derogations are provided for those
cases also, but subject to three tests: that the alternatives are technically
impossible, that they are prohibitively expensive, or that they produce a worse
overall environmental result.” For these cases the WFD
introduces the alternative goal of achieving ”Good
ecological potential”, i.e. the status of a heavily modified or an artificial
body of water (classified in accordance with the relevant provisions of Annex V
of the WFD):
Definitions for maximum, good and moderate
ecological potential for heavily modified or artificial water bodies
|
Element |
Maximum ecological
potential |
Good ecological
potential |
Moderate ecological
potential |
|
Biological quality
elements |
The values of the relevant biological quality
elements reflect, as far as possible, those associated with the closest
comparable surface water body type, given the physical conditions which
result from the artificial or heavily modified characteristics of the water
body. |
There are slight changes in the values of the
relevant biological quality elements as compared to the values found at
maximum ecological potential. |
There are moderate changes in the values of
the relevant biological quality elements as compared to the values found at
maximum ecological potential. These values are significantly more distorted
than those found under good quality. |
|
Hydromorphological elements |
The hydromorphological
conditions are consistent with the only impacts on the surface water body
being those resulting from the artificial or heavily modified characteristics
of the water body once all mitigation measures have been taken to ensure the
best approximation to ecological continuum, in particular with respect to
migration of fauna and appropriate spawning and breeding grounds. |
Conditions consistent with the achievement of
the values specified above for the biological quality elements. |
Conditions consistent with the achievement of
the values specified above for the biological quality elements. |
”Member
States may designate a body of surface water as artificial or heavily modified,
when:
(a)
the changes to the hydromorphological characteristics of that body which would
be necessary for achieving good ecological status would have significant
adverse effects on:
(i)
the wider environment;
(ii)
navigation, including port
facilities, or recreation;
(iii)
activities for the purposes
of which water is stored, such as drinking-water supply, power generation or
irrigation;
(iv)
water regulation, flood
protection, land drainage, or
(v)
other equally important
sustainable human development activities;
(b)
the beneficial objectives served by the artificial or modified
characteristics of the water body cannot, for reasons of technical feasibility
or disproportionate costs, reasonably be achieved by other means, which are a
significantly better environmental option.”
In
other words, the WFD recognises that there are water
resource uses, other than drinking water supply, that are of outstanding
importance to the society and which necessitate alternative prioritising goals.
The
purpose of this paper is to analyse the implications of the WFD
for hydroelectric generation. In doing so one also needs to consider EU’s ambition to increase the share of renewable energy as
set out in two documents entitled ”Towards a European strategy for the security
of energy supply” and ”Energy for the Future: Renewable sources of energy. White paper for a community strategy and action plan”,
respectively. According to the latter document, released in November
1997, hydroelectric power within the European Union is predicted to account for
105 GW by the year 2010 as compared to 92 GW in 1995. Large hydro is expected to increase its share
by 8.5 GW while small-scale hydro will increase from
9.5 to 14 GW between 1995 and 2010, respectively. The
forecast does not take into consideration any reduction in the current
generation of hydroelectricity that could result from future environmental
restrictions (the WFD was not known at the time but
the work that ultimately lead to the WFD had
commenced by 1997).
From
the classification of the ecological status and the environmental goals, as
outlined above, it is obvious that the presence of dams across rivers, whether
used for regulating the flow or simply to host a power station, will put the
watershed in the category “heavily modified water body”. The question remains,
however, if the river might still be attributed a ”good
ecological potential”. The definition of “maximum ecological potential” as was
cited above explicitly states that measures have then been taken “to ensure the
best approximation to ecological continuum, in particular with respect to
migration of fauna and appropriate spawning and breeding grounds.” Dams
equipped with ladders or other passage structures for fish may probably satisfy
this requirement whereas dams lacking such facilities do not. It is still not
clear, however, if the less rigorous requirement that would place the watershed
in the next category, i.e. one having a “good ecological potential”, is
fulfilled where dams obstruct the dispersal of fish and other riverine
organisms. The WFD is not specific on this point.
It
is obvious that hydromorphological aspects are much
more difficult to handle compared to for example concentrations of pollutants
where environmental standards are already established and integrated in the WFD. The basic hydromorphology
and its resultant setup of aquatic communities varies
considerably between different geographic regions as do the impact of man-made
structures. A low-head dam located near a river mouth probably exerts a
stronger impact on the ecosystem compared to a high-head dam far up in the
mountains. It would consequently be unwise to try to apply identical
environmental criteria on these dams. Numerous other examples could be used to
illustrate the need to differentiate environmental management according to the
natural ecological setting.
In
semantic terms “good ecological potential” means a situation where a decision
to end a certain disturbing activity would result in a return to natural or
near natural ecological conditions (given the fact that the WFD
makes reference to natural or more pristine conditions when defining the
goals). However, the arguments for realising good ecological status would be
different if this condition could be achieved at any time and at approximately
the same costs or if the uninterrupted disturbance would lead to a successive
deterioration of the overall ecological conditions with an ultimate risk of
irreversible damages or immense future costs. It is clear that releases of
toxic substances may lead to persistent health effects and that pollution
control would reduce the overall and integrated burden. It is, however, less
clear that time per se is essential
for the prospects of restoring ecological conditions following physical changes
in the environment.
The
question of the reversibility of impacts of natural resource utilisation is
vital for the interpretation of “good ecological potential”. Its satisfaction
is generally implicated in both agriculture and forestry, i.e. two other kind
of natural resource use with the potential to provide renewable energy. So
forth, “reversibility” is rarely interpreted in connection with river
regulation.
It is not clear what disturbances caused
by artificially altered water regimes represent in terms of prospects of future
recovery. However, scientific evidence indicates that damages are generally
reversible, i.e. conditions change spontaneously and adhere to near natural
after a few years following the return of the natural flow. One reason for this
is probably that river regulation only influence part of the catchment, leaving
many tributaries undisturbed. Biotope remains that can act as refuges for
re-colonising organisms are then still available. Thus, there is no known loss
of a species from any of the regulated rivers in
It
is obvious that a careful analysis of the WFD and its
potential consequences for the operation of hydroelectric facilities is needed.
Some lines of reasoning, based on the above interpretation of “good ecological
potential”, are, however, obvious already at this stage.
If
the current use of water resources is important for satisfying societal needs
and is not expected to lead to a successive depletion of biological resources
or health risks, one should view the expected environmental gains of reducing
this use in a utilitarian perspective. The same conclusion applies to
situations where the use of water resources has led to irreversible damages. In
the latter case one also needs to consider if irreversibility is absolute or if
it is related to the time horizon.
A
use of water resources that leads to a progressive loss of ecological amenities
should be handled in a completely different way. Relevant environmental
standards and subsequent modifications of this kind of water use have then the
capacity to halt or even reverse the aggravation. However, it is necessary to
evaluate the overall consequences also in this case. A reduction of peaking
power capacity, for example, might necessitate the construction of
fossil-fuelled gas turbines or lead to a less reliable supply of electricity.
Loss
of hydropower also means that the environmental burden of alternative means of
power production must be considered. The WFD allows
for cost-benefit analyses, but it is probably necessary to stress the
importance of such analyses further. At present and following the
implementation of other energy related EU directives, it is sufficient to
consider only other renewable energy sources. Scientific data that can be of
assistance in such comparisons should be compiled and evaluated. Some initial
attempts to do so in