Ref. Ares(2023)389474 - 18/01/2023
Ref. Ares(2023)782205 - 02/02/2023
WHY IS NATURE RESTORATION
CRITICAL FOR RIVER CONNECTIVITY?
Publication date: December 2022
Authors: Eleftheria Kampa (Ecologic Institute)
The EU has a target to reach good ecological status for all surface water bodies
including rivers by 2015, at
the latest by 2027, based on the Water Framework Directive (WFD). However, implementation of the WFD is
lagging behind and enforcement must be stepped up. In 2015, only 44 % of EU water bodies were in good
or better ecological status. The Biodiversity Strategy to 2030 called for greater efforts and concrete actions
to restore freshwater ecosystems and the natural functions of rivers to support the WFD objectives. To restore
the natural functions of rivers, the Strategy sets a target to restore by 2030 at least 25,000 km of rivers into
free-flowing rivers through the removal of river barriers and the restoration of floodplains and wetlands.
Healthy rivers require a high degree of connectivity to support the complex life
cycles of many aquatic species and a functioning ecosystem. Only with healthy,
biodiverse water bodies can we allow nature to thrive, ensure clean and sufficient
water supply, and resilience to climate change impacts [1].
River connectivity in Europe is hindered by a very large number of barriers on EU rivers (
at least 1.2 million
barriers) and it is expected that
only few EU rivers are at present free-flowing. Relatively barrier-free rivers
can still be found in the Balkans, the Baltic states, and parts of Scandinavia and southern Europe [2].
A significant number of these man-made river barriers could be removed, as they are no longer useful
(obsolete barriers). The reconnected reaches combined with other river restoration measures can serve as
habitats to restore the populations of several fish and other species.
Gäddede, Sweden, Photo by Jon Flobrant
Why is nature restoration critical for river connectivity?
WHAT CAN THE NATURE RESTORATION LAW ACHIEVE?
The requirement of the NRL to make an
inventory
The Nature Restoration Law (NRL) asks
of barriers to longitudinal and lateral
Member States to make an
inventory of
connectivity is a crucial first step, because existing
barriers to longitudinal and lateral
barrier records underestimate true barrier numbers
connectivity of surface waters and identify the
with considerable variation between EU countries
barriers that need to be removed to contribute
[3]. For barriers to lateral connectivity, there is no
to the achievement of the NRL restoration
systematic overview or mapping at EU level to
targets for relevant habitats and species.
support the development of sound strategies for
barrier removal and to monitor progress.
Restoring rivers to free-flowing state is designed to support and foster the achievement of the WFD
objectives, as well as to boost broader river restoration efforts for the
benefit of habitats and species [4].
The removal of barriers aims to help rivers
re-establish their natural water and sediment flow, and
free-
up migration routes of fish such as salmon, eel and sturgeon and other aquatic species, whose habitats
have become isolated through river fragmentation [5].
• River barriers have been identified as a
significant pressure under the WFD for at least 20%
of EU river water bodies, contributing to the non-achievement of good ecological status [6].
• The presence of river barriers also affects the
condition and conservation status of protected
habitats and species. Under the Habitats Directive,
the top group of pressures affecting
freshwater
habitats is the
modification of hydrology and
hydro-morphology (with
over 33 % of all
pressure records reported as “high-ranking”)
including among others dams and reservoirs,
drainage, water abstraction.
• Habitat fragmentation and the lack of connectivity
in European rivers impacts river biota. Since 1970,
migratory freshwater fish in Europe declined by
93% [7] to a large extent owing to the
fragmentation of migratory routes.
• Until 2020, Dam Removal Europe [8] has
documented the removal of at least 4,984
longitudinal barriers in selected countries.
Even a
small number of strategic barrier removals can
have a significant positive impact: the Open
Aosta, Italy, Photo by Mario Álvarez
Rivers Programme [9], for example, claims that by
removing just 19 specific dams, the programme-
supported projects will free 386 km of rivers [10].
2
Why is nature restoration critical for river connectivity?
•
Free-flowing rivers offer numerous benefits, including improved fishery yields, regulation of
floods, recreation, aesthetics, and water quality advantages. With increasing experience of
barrier removals in Europe, evidence becomes available on the benefits of free-flowing rivers for
humans, biodiversity, and landscapes. Several studies using monitoring data after
barrier
removal measures show positive changes in fish communities. For example, 30 years of data
in Denmark reveal dramatic increase in abundance of the brown trout following dam removal
(Birnie-Gauvin et al, 2017) [11].
The
status of river floodplains is also closely linked to the free-flowing status of rivers. Measures taken to
restore free-flowing rivers will contribute to the restoration of degraded floodplains and re-establish the
connectivity of rivers to their floodplain.
•
70-90 % of European floodplains have been environmentally degraded because of
structural flood protection, river straightening, disconnection of floodplain wetlands from the
river, agricultural land use and urbanisation over the past two centuries [12].
•
Only 17% of habitats found in floodplains are in favourable conservation status, and for
some large biogeographic regions no floodplain habitats are in favourable conservation status
[13].
• Natural floodplains are important for biodiversity and many ecosystem services.
Floodplains
host unique and diverse fauna and flora. Floodplains provide ecosystem services like natural
habitats, drinking water, carbon storage, flood protection, and recreation.
• If kept in a good condition or restored, the
carbon stock capacity of riparian, fluvial and
swamp forests is estimated to be between 6- 8 Gt CO2-eq and their
carbon sequestration
potential per year is calculated to range between 15,129 and 95,171 kt CO2 eq yr-1 [14].
Morava floodplain, Photo by Tomasz Anusiewicz
3
References
1. https://wwfeu.awsassets.panda.org/downloads/river_connectivity___lre_briefing.pdf
2. Belletti et al., 2020, More than one million barriers fragment Europe’s rivers. Nature 588, 436–441 (2020).
https://doi.org/10.1038/s41586-020-3005-2
3. AMBER Policy Brief 1, 2020, https://amber.international/wp-content/uploads/2020/11/AMBER-policy-Brief-1.pdf
4. https://environment.ec.europa.eu/publications/guidance-barrier-removal-river-restoration_en
5. See https://www.eea.europa.eu/themes/water/european-waters/water-use-and-environmental-pressures/tracking-barriersand-
their-impacts
6. EEA (2021). Drivers of and pressures arising from selected key water management challenges — A European overview. EEA Report
No 9/2021. European Environment Agency, Luxembourg.
7. The Living Planet Index for migratory freshwater fish (2020),
https://wwfeu.awsassets.panda.org/downloads/lpi_migratory_freshwater_fish_low_min_1.pdf
8. https://damremoval.eu/about/
9. https://openrivers.eu/open-rivers-programme-supports-19-new-dam-removal-projects-opening-up-386-km-of-river/
10. https://www.freeflowingrivers.eu/home
11. https://www.sciencedirect.com/science/article/pii/S0301479717308848?via%3Dihub
12. EEA (2019). Floodplains: a natural system to preserve and restore. EEA Report. No 24/2019. European Environment Agency,
Luxembourg.
13. https://water.europa.eu/freshwater/europe-freshwater/freshwater-themes/floodplains
14.
https://www.eionet.europa.eu/etcs/etc-di/products/etc-uls-report-10-2021-carbon-pools-and-sequestration-potential-
ofwetlands-in-the-european-union
Funded by the European Union. Views and opinions expressed are however
those of the author(s) only and do not necessarily reflect those of the
European Union or CINEA. Neither the European Union nor CINEA can be held
responsible for them.
These policy briefs were written by IEEP and
Ecologic Institute in the Think Sustainable Europe
Network in response to the proposed EU nature
restoration law.
