Geoscience Reference
In-Depth Information
be flooded for 80 days per year. The high water-
levels in times of flooding will make it difficult for
channel vegetation to develop owing to the high
water velocities. However, in the area as a whole
features typical of a lowland river mouth should
develop, producing a variety of wetland habitats
and vegetation such as alder (
Alnus
spp.) floodplain
forest, sedges (
Carex
spp.), reedmace (
Typha
spp.),
reed (
Phragmites australis
) flotegrass (
Glyceria
spp.)
and various pondweeds (
Potamogeton
spp.).
simultaneously requires the understanding and
close cooperation of the customers and members
of the Emschergenossenschaft. This applies not
only to the municipalities but also to industrial
partners - often major international businesses -
which require considerable persuasion that formal
and informal tasks are best accomplished together.
Local support for river restoration is a fundamental
requirement ( Aberg and Tapsell, this volume) and
regular sharing of work steps between the various
disciplines leads to a much more efficient planning
process and more relevant outcomes.
Monitoring
Monitoring progress of the rehabilitation work
is extremely important, particularly if the design
or location of structures need to be changed
because they are not producing the required or
anticipated results. The monitoring programme
for the Emscher includes water quantity, water
quality,
Conclusions
There are significant advantages in including
the whole river as part of a major long-term
regional economic regeneration programme, not
least because of the scale of financial investment
involved. The economic and environmental
benefits can be significant, even if the scale of
previous modification caused by industrialization
and mining prevents full restoration of the river.
An ecological concept for the catchment is
helpful for spatial planning of river rehabilitation.
Exploiting opportunities to allow the river to
develop more naturally, such as using natural
recolonization sources provided by tributaries,
and developing ecological 'hotspots' should allow
ecological recovery to be maximized, although this
will take time to happen.
biological
indicators
and
morphological
structure.
Survey
and
assessment
methods
are
based on WFD requirements.
At present about 20 streams which have
already been rehabilitated now have sand substrate
expected for the Emscher under more natural
conditions. The streams have been colonized
by about 400 species of invertebrates (mainly
molluscs, crustaceans, oligochaetes and aquatic
insects) and a variety of fish species; the incoming
fauna also includes some rare species (Semrau
et al
.,
2011).
Discussion
Acknowledgements
Despite being used for wastewater management
for such a long time, the Emscher offers good
potential for a new ecological system with
major benefits both for humans and nature.
An important objective of integrated river basin
management in the Emscher catchment has been
to combine technical work on landscape and urban
development with related projects on art, leisure
and waterfront architecture (Braioni
et al
., this
volume). This contribution to a multi-disciplinary
spatial planning approach has proved to be very
successful.
This chapter is based largely on material in a
paper given at The 4th European Centre for
River Restoration (ECRR) conference in Venice
in June 2008. The ECRR is thanked for allowing
parts of that material to be reproduced from the
Proceedings.
References
Council of the European Communities (2000) Directive
2000/60/EC of the European Parliament and of the
However,
to
achieve
several
goals
