Published February 25, 2026
| Version v1
Journal article
Open
Challenges and opportunities in restoring European free-flowing rivers
Authors/Creators
- 1. Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Department of Community and Ecosystem Ecology, Berlin, Germany|Wageningen University & Research (WUR), Aquaculture Biology and Fisheries Ecology group, Wageningen, Netherlands
- 2. North Rhine-Westphalia State Agency for Nature, Environment and Consumer Protection, Recklinghausen, Germany
- 3. Federal Agency for Nature Conservation (BfN), Bonn, Germany
- 4. Helmholtz-Centre for Environmental Research (UFZ), Department Conservation Biology & Social-Ecological Systems, Leipzig, Germany
- 5. Wageningen University & Research (WUR), Aquaculture Biology and Fisheries Ecology group, Wageningen, Netherlands
Description
Free-flowing rivers (FFRs) across Europe hold high ecological value and clear economic benefits. They support biodiversity by providing habitats for a wide range of aquatic and terrestrial species and strengthen local economies through sustainable practices while reducing the need for costly artificial flood control and water treatment. Rivers also carry deep cultural meaning for European communities, shaping identity, belonging, and wellbeing. Given this ecological, economic, and cultural weight, we argue that safeguarding remaining near-natural or pristine rivers should be the first priority, alongside restoring degraded systems, where meaningful gains are feasible. Herein, we review definitions, restoration objectives, and historical changes in FFRs, and highlight the importance of setting realistic reference conditions that recognise both ecological constraints and future climate change. We stress the value of combining multiple temporal and spatial perspectives in project design and discuss practical restoration and rehabilitation approaches, including the role of stakeholder involvement and public awareness, to achieve successful outcomes. We then consider how biodiversity and climate policies can support protection, restoration, and long-term management of river ecosystems across Europe. Finally, we examine the opportunities and challenges tied to implementing the Nature Restoration Regulation and the EU Biodiversity Strategy for 2030, as well as other policy initiatives, that can help remove obstacles and create better conditions for accelerating progress in restoring free-flowing rivers.
HighlightsNear-pristine rivers should be protected immediately, even with incomplete data.
Freshwater systems need more political attention and stronger stakeholder involvement.
Solutions for FFR restoration should be tailor-made for each unique situation.
FFRs connect diverse ecosystems, needing both meta- and local ecosystem approaches.
Few reference rivers exist; clarifying reference sites and ecological conditions is needed.
Files
NC_article_173762.pdf
Files
(4.7 MB)
| Name | Size | Download all |
|---|---|---|
|
md5:099e859cc1f879cb63cf70527a4da022
|
4.6 MB | Preview Download |
|
md5:77963f3fd6a56da2eeb9bad933cb35bc
|
132.0 kB | Preview Download |
Linked records
Additional details
References
- Acreman MC, Ferguson AJD (2010) Environmental flows and the European water framework directive. Freshwater Biology 55(1): 32–48. https://doi.org/10.1111/j.1365-2427.2009.02181.x
- Albert JS, Destouni G, Duke-Sylvester SM, Magurran AE, Oberdorff T, Reis RE, Winemiller KO, Ripple WJ (2021) Scientists' warning to humanity on the freshwater biodiversity crisis. Ambio 50: 85–94. https://doi.org/10.1007/s13280-020-01318-8
- Allen DC, Kopp DA, Costigan KH, Datry T, Hugueny B, Turner DS, Bodner GS, Flood TJ (2019) Citizen scientists document long-term streamflow declines in intermittent rivers of the desert southwest USA. Freshwater Science 38: 244–256. https://doi.org/10.1086/701483
- Altermatt F (2013) Diversity in riverine metacommunities: A network perspective. Aquatic Ecology 47: 365–377. https://doi.org/10.1007/s10452-013-9450-3
- Arthington AH, Bunn SE, Poff NL, Naiman RJ (2006) The challenge of providing environmental flow rules to sustain river ecosystems. Ecological Applications: A Publication of the Ecological Society of America 16: 1311–1318. https://doi.org/10.1890/1051-0761(2006)016[1311:TCOPEF]2.0.CO;2
- Arthington AH, Tickner D, McClain ME, Acreman MC, Anderson EP, Babu S, Dickens CW, Horne AC, Kaushal N, Monk WA (2023) Accelerating environmental flows implementation to bend the curve of global freshwater biodiversity loss. Environmental Reviews 32(3): 387–413. https://doi.org/10.1139/er-2022-0126
- Baldan D, Chattopadhyay S, Prus P, Funk A, Keller A, Piniewski M (2022) Regionalization strategy affects the determinants of fish community structure. Ecohydrology 15: e2425. https://doi.org/10.1002/eco.2425
- Bauer S, Hoye BJ (2014) Migratory animals couple biodiversity and ecosystem functioning worldwide. Science 344: 1242552. https://doi.org/10.1126/science.1242552
- Belletti B, de Leaniz CG, Jones J, Bizzi S, Börger L, Segura G, Castelletti A, Van de Bund W, Aarestrup K, Barry J (2020) More than one million barriers fragment Europe's rivers. Nature 588: 436–441. https://doi.org/10.1038/s41586-020-3005-2
- Birk S, Anzaldua G, Baattrup-Pedersen A, Bérczi-Siket A, Blackstock K, Buijse T, Carmen E, Carvalho L, Garcia X, Gerner N, Grondard N, Hernandez Herrero E, Ibrahim A, Kok S, Lenz M-I, Nyírő F, Okruszko T, Penning E, Pott L, Rouillard J, Schmidt-Kloiber A, Schwerk A, Sommerhäuser MM, St. John R, Waylen K, Hering D (2026) Building blocks for upscaling freshwater ecosystem restoration: Place-based strategies for a transdisciplinary challenge. In: Kaden US, Schmid S, Wulf S, Marsden K, Klusmann C, Bonn A, Tockner K, Scholz M (Eds) Wetlands in a Changing Climate: Restoring Coasts and Floodplains. Nature Conservation 62: 261–287. https://doi.org/10.3897/natureconservation.62.148938
- Bizzi S, Lerner DN (2015) The use of stream power as an indicator of channel sensitivity to erosion and deposition processes. River Research and Applications 31: 16–27. https://doi.org/10.1002/rra.2717
- Blackbourn D (2007) The Conquest of Nature: Water Landscape and the Making of Modern Germany. W. W. Norton Company. https://www.math.chalmers.se/~ulfp/Review/conquest.pdf
- BMUV and BMV (2019) Fachliche Grundlagen zum Bundesprogramm "Blaues Band Deutschland" - Gutachten im Auftrag des Bundesministeriums für Umwelt Klimaschutz Naturschutz und nukleare Sicherheit (BMUV) und des Bundesministeriums für Verkehr (BMV), erarbeitet durch: Generaldirektion Wasserstraßen und Schifffahrt Bundesanstalt für Gewässerkunde Bundesanstalt für Wasserbau Bundesamt für Naturschutz Umweltbundesamt, 176 pp. https://www.blaues-band.bund.de/Projektseiten/Blaues_Band/DE/05_Informationen/Fachinformationen/Fachstudie_BBD.html?nn=958192
- Brettschneider DJ, Spring T, Blumer M, Welge L, Dombrowski A, Schulte-Oehlmann U, Sundermann A, Oetken M, Oehlmann J (2023) Much effort, little success: Causes for the low ecological efficacy of restoration measures in German surface waters. Environmental Sciences Europe 35: 31. https://doi.org/10.1186/s12302-023-00736-1
- Bunn SE, Arthington AH (2002) Basic principles and ecological consequences of altered flow regimes for aquatic biodiversity. Environmental Management 30: 492–507. https://doi.org/10.1007/s00267-002-2737-0
- Carlson PE, McKie BG, Sandin L, Johnson RK (2016) Strong land‐use effects on the dispersal patterns of adult stream insects: Implications for transfers of aquatic subsidies to terrestrial consumers. Freshwater Biology 61: 848–861. https://doi.org/10.1111/fwb.12745
- Carpenter‐Bundhoo L, Butler GL, Espinoza T, Bond NR, Bunn SE, Kennard MJ (2020) Reservoir to river: Quantifying fine‐scale fish movements after translocation. Ecology Freshwater Fish 29: 89–102. https://doi.org/10.1111/eff.12490
- Carraro L, Altermatt F (2022) Optimal Channel Networks accurately model ecologically-relevant geomorphological features of branching river networks. Communications Earth & Environment 3: 125. https://doi.org/10.1038/s43247-022-00454-1
- Chiu M-C, Leigh C, Mazor R, Cid N, Resh V (2017) Anthropogenic threats to intermittent rivers and ephemeral streams. Intermittent rivers and ephemeral streams. Elsevier, 433–454. https://doi.org/10.1016/B978-0-12-803835-2.00017-6
- Cid N, Erős T, Heino J, Singer G, Jähnig SC, Cañedo-Argüelles M, Bonada N, Sarremejane R, Mykrä H, Sandin L, Paloniemi R, Varumo L, Datry T (2022) From meta-system theory to the sustainable management of rivers in the Anthropocene. Frontiers in Ecology and the Environment 20: 49–57. https://doi.org/10.1002/fee.2417
- Constantine JA, Dunne T (2008) Meander cutoff and the controls on the production of oxbow lakes. Geology 36: 23–26. https://doi.org/10.1130/G24130A.1
- Costea G, Pusch MT, Bănăduc D, Cosmoiu D, Curtean-Bănăduc A (2021) A review of hydropower plants in Romania: Distribution, current knowledge, and their effects on fish in headwater streams. Renewable & Sustainable Energy Reviews 145: 111003. https://doi.org/10.1016/j.rser.2021.111003
- Cote D, Kehler DG, Bourne C, Wiersma YF (2009) A new measure of longitudinal connectivity for stream networks. Landscape Ecology 24: 101–113. https://doi.org/10.1007/s10980-008-9283-y
- Couto TB, Olden JD (2018) Global proliferation of small hydropower plants-science and policy. Frontiers in Ecology and the Environment 16: 91–100. https://doi.org/10.1002/fee.1746
- de Jalón DG, Bussettini M, Rinaldi M, Grant G, Friberg N, Cowx IG, Magdaleno F, Buijse T (2016) Linking environmental flows to sediment dynamics. Water Policy 19: 358–375. https://doi.org/10.2166/wp.2016.106
- de Leaniz CG, O'Hanley JR (2022) Operational methods for prioritizing the removal of river barriers: Synthesis and guidance. The Science of the Total Environment 157471. https://doi.org/10.1016/j.scitotenv.2022.157471
- Dolan EJ, Soto I, Dick JT, He F, Cuthbert RN (2025) Riverine barrier removals could proliferate biological invasions. Global Change Biology 31(3): e70093. https://doi.org/10.1111/gcb.70093
- Dudgeon D, Arthington AH, Gessner MO, Kawabata Z-I, Knowler DJ, Lévêque C, Naiman RJ, Prieur-Richard A-H, Soto D, Stiassny ML (2006) Freshwater biodiversity: Importance, threats, status and conservation challenges. Biological Reviews of the Cambridge Philosophical Society 81: 163–182. https://doi.org/10.1017/S1464793105006950
- EEA (2018) Environmental indicator report 2018 — In support to the monitoring of the Seventh Environment Action Programm. EEA Report. European Environment Agency. http://doi.org/10.2800/180334
- EEA (2019) The European environment — state and outlook 2020: knowledge for transition to a sustainable Europe. European Environment Agency.
- Environment Agency (2022) RiverWiki: An interactive source of information on river restoration schemes from around Europe. https://www.restorerivers.eu/
- Erős T, Grant EHC (2015) Unifying research on the fragmentation of terrestrial and aquatic habitats: Patches, connectivity and the matrix in riverscapes. Freshwater Biology 60: 1487–1501. https://doi.org/10.1111/fwb.12596
- Erős T, Lowe WH (2019) The landscape ecology of rivers: From patch-based to spatial network analyses. Current Landscape Ecology Reports 4: 103–112. https://doi.org/10.1007/s40823-019-00044-6
- Erős T, O'Hanley JR, Czeglédi I (2018) A unified model for optimizing riverscape conservation. Journal of Applied Ecology 55: 1871–1883. https://doi.org/10.1111/1365-2664.13142
- Erős T, Hermoso V, Langhans SD (2023) Leading the path toward sustainable freshwater management: Reconciling challenges and opportunities in historical, hybrid, and novel ecosystem types. WIREs Water, e1645. https://doi.org/10.1002/wat2.1645
- European Commission (2022) Biodiversity strategy for 2030 - Barrier removal for river restoration. Publications Office of the European Union. https://environment.ec.europa.eu/system/files/2021-12/Barrier%20removal%20for%20river%20restoration.pdf
- Fišer C, Borko Š, Delić T, Kos A, Premate E, Zagmajster M, Zakšek V, Altermatt F (2022) The European Green Deal misses Europe's subterranean biodiversity hotspots. https://doi.org/10.1038/s41559-022-01859-z
- Flávio H, Ferreira P, Formigo N, Svendsen JC (2017) Reconciling agriculture and stream restoration in Europe: A review relating to the EU Water Framework Directive. The Science of the Total Environment 596: 378–395. https://doi.org/10.1016/j.scitotenv.2017.04.057
- Foley MM, Bellmore J, O'Connor JE, Duda JJ, East AE, Grant G, Anderson CW, Bountry JA, Collins MJ, Connolly PJ (2017) Dam removal: Listening in. Water Resources Research 53: 5229–5246. https://doi.org/10.1002/2017WR020457
- Fukui D, Murakami M, Nakano S, Aoi T (2006) Effect of emergent aquatic insects on bat foraging in a riparian forest. The Journal of Animal Ecology 75: 1252–1258. https://doi.org/10.1111/j.1365-2656.2006.01146.x
- Gardner RC, Finlayson C (2018) Global wetland outlook: state of the World's wetlands and their services to people. Ramsar Convention Secretariat: 2020–2025. https://ssrn.com/abstract=3261606
- Geerling GW, Ragas AMJ, Leuven RSEW, Van den Berg JH, Breedveld M, Liefhebber D, Smits AJM (2006) Succession and rejuvenation in floodplains along the river Allier (France). Hydrobiologia 565(1): 71–86. https://doi.org/10.1007/s10750-005-1906-6
- Geist J (2021) Green or red: Challenges for fish and freshwater biodiversity conservation related to hydropower. Aquatic Conservation 31: 1551–1558. https://doi.org/10.1002/aqc.3597
- Gounand I, Little CJ, Harvey E, Altermatt F (2018) Cross-ecosystem carbon flows connecting ecosystems worldwide. Nature Communications 9: 4825. https://doi.org/10.1038/s41467-018-07238-2
- Grill G, Lehner B, Thieme M, Geenen B, Tickner D, Antonelli F, Babu S, Borrelli P, Cheng L, Crochetiere H (2019) Mapping the world's free-flowing rivers. Nature 569: 215–221. https://doi.org/10.1038/s41586-019-1111-9
- Guetz K, Joyal T, Dickson B, Perry D (2022) Prioritizing dams for removal to advance restoration and conservation efforts in the western United States. Restoration Ecology 30: e13583. https://doi.org/10.1111/rec.13583
- Haidvogl G (2018) Historic milestones of human river uses and ecological impacts. Riverine Ecosystem Management: Science for Governing Towards A Sustainable Future: 19–39. https://doi.org/10.1007/978-3-319-73250-3_2
- Havrdová A, Douda J, Doudová J (2023) Threats, biodiversity drivers and restoration in temperate floodplain forests related to spatial scales. The Science of the Total Environment 854: 158743. https://doi.org/10.1016/j.scitotenv.2022.158743
- Hering D, Schürings C, Wenskus F, Blackstock K, Borja A, Birk S, Bullock C, Carvalho L, Dagher-Kharrat MB, Lakner S, Lovrić N, McGuinness S, Nabuurs G-J, Sánchez-Arcilla A, Settele J, Pe'er G (2023) Securing success for the Nature Restoration Law. Science 382: 1248–1250. https://doi.org/10.1126/science.adk1658
- Hermoso V, Abell R, Linke S, Boon P (2016) The role of protected areas for freshwater biodiversity conservation: Challenges and opportunities in a rapidly changing world. Aquatic Conservation 26: 3–11. https://doi.org/10.1002/aqc.2681
- Hermoso V, Clavero M, Filipe AF (2021) An accessible optimisation method for barrier removal planning in stream networks. Science of the Total Environment 752: 141943. https://doi.org/10.1016/j.scitotenv.2020.141943
- Hermoso V, Carvalho S, Giakoumi S, Goldsborough D, Katsanevakis S, Leontiou S, Markantonatou V, Rumes B, Vogiatzakis I, Yates K (2022) The EU Biodiversity Strategy for 2030: Opportunities and challenges on the path towards biodiversity recovery. Environmental Science & Policy 127: 263–271. https://doi.org/10.1016/j.envsci.2021.10.028
- Hohensinner S, Habersack H, Jungwirth M, Zauner G (2004) Reconstruction of the characteristics of a natural alluvial river-floodplain system and hydromorphological changes following human modifications: The Danube River (1812–1991). River Research and Applications 20: 25–41. https://doi.org/10.1002/rra.719
- Hohensinner S, Egger G, Muhar S, Vaudor L, Piégay H (2021) What remains today of pre‐industrial Alpine rivers? Census of historical and current channel patterns in the Alps. River Research and Applications 37: 128–149. https://doi.org/10.1002/rra.3751
- Hölker F, Jechow A, Schroer S, Tockner K, Gessner MO (2023) Light pollution of freshwater ecosystems: Principles, ecological impacts and remedies. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 378: 20220360. https://doi.org/10.1098/rstb.2022.0360
- Huddart JE, Thompson MS, Woodward G, Brooks SJ (2016) Citizen science: From detecting pollution to evaluating ecological restoration. Wiley Interdisciplinary Reviews: Water 3: 287–300. https://doi.org/10.1002/wat2.1138
- Jacquet C, Carraro L, Altermatt F (2022) Meta‐ecosystem dynamics drive the spatial distribution of functional groups in river networks. Oikos 2022: e09372. https://doi.org/10.1111/oik.09372
- Jaeger KL, Olden JD, Pelland NA (2014) Climate change poised to threaten hydrologic connectivity and endemic fishes in dryland streams. Proceedings of the National Academy of Sciences of the United States of America 111: 13894–13899. https://doi.org/10.1073/pnas.1320890111
- Jones PE, Consuegra S, Börger L, Jones J, Garcia de Leaniz C (2020) Impacts of artificial barriers on the connectivity and dispersal of vascular macrophytes in rivers: A critical review. Freshwater Biology 65: 1165–1180. https://doi.org/10.1111/fwb.13493
- Jones PE, Tummers JS, Galib SM, Woodford DJ, Hume JB, Silva LG, Lucas MC (2021) The use of barriers to limit the spread of aquatic invasive animal species: A global review. Frontiers in Ecology and Evolution 9: 611631. https://doi.org/10.3389/fevo.2021.611631
- Jumani S, Andrews L, Grantham TE, McKay SK, Duda J, Howard J (2023) A decision‐support framework for dam removal planning and its application in northern California. Environmental Challenges 12: 100731. https://doi.org/10.1016/j.envc.2023.100731
- Kaden US, Schmid S, Vieweg M, Scholz M, Dufour S (2026) European riverine and coastal wetlands under pressure: biodiversity and climate change. In: Kaden US, Schmid S, Wulf S, Marsden K, Klusmann C, Bonn A, Tockner K, Scholz M (Eds) Wetlands in a Changing Climate: Restoring Coasts and Floodplains. Nature Conservation 62: 13–45. https://doi.org/10.3897/natureconservation.62.163636
- Keeley AT, Fremier AK, Goertler PA, Huber PR, Sturrock AM, Bashevkin SM, Barbaree BA, Grenier JL, Dilts TE, Gogol-Prokurat M (2022) Governing ecological connectivity in cross-scale dependent systems. Bioscience 72: 372–386. https://doi.org/10.1093/biosci/biab140
- Klusmann C, Brotherton P, Schiller T, Wulf S, Marsden K (2026) Wetlands in the EU policy context. In: Kaden US, Schmid S, Wulf S, Marsden K, Klusmann C, Bonn A, Tockner K, Scholz M (Eds) Wetlands in a Changing Climate: Restoring Coasts and Floodplains. Nature Conservation 62: 317–335. https://doi.org/10.3897/natureconservation.62.163780
- Kmetova-Biro E, Rožac V, Frank G, Marušić M, Lagutov V (2026) Bridging protected areas along the Danube. In: Kaden US, Schmid S, Wulf S, Marsden K, Klusmann C, Bonn A, Tockner K, Scholz M (Eds) Wetlands in a Changing Climate: Restoring Coasts and Floodplains. Nature Conservation 62: 217–236. https://doi.org/10.3897/natureconservation.62.160887
- Knez S, Štrbac S, Podbregar I (2022) Climate change in the Western Balkans and EU Green Deal: Status, mitigation and challenges. Energy, Sustainability and Society 12: 1–14. https://doi.org/10.1186/s13705-021-00328-y
- Koenzen U, Kurth A, Günther-Diringer D (2021) Status Report on Floodplains 2021 - Floodplains in Germany. Federal Agency for Nature Conservation (BfN), The Federal Ministry for the Environment Nature Conservation and Nuclear Safety (BMU), Bonn. https://doi.org/10.19217/brs211en
- Lane CR, Creed IF, Golden HE, Leibowitz SG, Mushet DM, Rains MC, Wu Q, D'Amico E, Alexander LC, Ali GA (2023) Vulnerable waters are essential to watershed resilience. Ecosystems (New York, N.Y.) 26: 1–28. https://doi.org/10.1007/s10021-021-00737-2
- Lenders HJR (2003) Environmental rehabilitation of the river landscape in the Netherlands: a blend of five dimensions. https://repository.ubn.ru.nl/bitstream/handle/2066/19357/19357_envireoft.pdf
- Lennox RJ, Crook DA, Moyle PB, Struthers DP, Cooke SJ (2019) Toward a better understanding of freshwater fish responses to an increasingly drought-stricken world. Reviews in Fish Biology and Fisheries 29: 71–92. https://doi.org/10.1007/s11160-018-09545-9
- Lindenmayer D (2020) Improving restoration programs through greater connection with ecological theory and better monitoring. Frontiers in Ecology and Evolution 8: 50. https://doi.org/10.3389/fevo.2020.00050
- Maasri A, Jähnig SC, Adamescu MC, Adrian R, Baigun C, Baird DJ, Batista‐Morales A, Bonada N, Brown LE, Cai Q (2022) A global agenda for advancing freshwater biodiversity research. Ecology Letters 25: 255–263. https://doi.org/10.1111/ele.13931
- Macháč J, Zaňková L, Hekrle M, Scholz M (2026) Nature-based solutions with sponge functions: socio-economic importance and valuation. In: Kaden US, Schmid S, Wulf S, Marsden K, Klusmann C, Bonn A, Tockner K, Scholz M (Eds) Wetlands in a Changing Climate: Restoring Coasts and Floodplains. Nature Conservation 62: 289–315. https://doi.org/10.3897/natureconservation.62.164530
- Magilligan FJ, Graber BE, Nislow KH, Chipman JW, Sneddon CS, Fox CA (2016) River restoration by dam removal: Enhancing connectivity at watershed scalesRiver restoration by dam removal. Elementa 4. https://doi.org/10.12952/journal.elementa.000108
- Messager ML, Lehner B, Cockburn C, Lamouroux N, Pella H, Snelder T, Tockner K, Trautmann T, Watt C, Datry T (2021) Global prevalence of non-perennial rivers and streams. Nature 594: 391–397. https://doi.org/10.1038/s41586-021-03565-5
- Mueller M, Pander J, Geist J (2011) The effects of weirs on structural stream habitat and biological communities. Journal of Applied Ecology 48(6): 1450–1461. https://doi.org/10.1111/j.1365-2664.2011.02035.x
- Nagel C, Pander J, Droll J, Loy G, Grüner B, Wesemann J, Geist J (2025) Fish and chips: Conservation of freshwater fish populations through an integrative multi-stakeholder approach. Journal of Applied Ecology 62: 744–752. https://doi.org/10.1111/1365-2664.70004
- Olden JD, Poff NL (2003) Toward a mechanistic understanding and prediction of biotic homogenization. The American Naturalist 162: 442–460. https://doi.org/10.1086/378212
- Opperman JJ, Shahbol N, Maynard J, Grill G, Higgins J, Tracey D, Thieme M (2021) Safeguarding free-flowing rivers: The global extent of free-flowing rivers in protected areas. Sustainability 13: 2805. https://doi.org/10.3390/su13052805
- Palmer M, Ruhi A (2019) Linkages between flow regime, biota, and ecosystem processes: Implications for river restoration. Science 365: 134915. https://doi.org/10.1126/science.aaw2087
- Palmer MA, Lettenmaier DP, Poff NL, Postel SL, Richter B, Warner R (2009) Climate change and river ecosystems: Protection and adaptation options. Environmental Management 44: 1053–1068. https://doi.org/10.1007/s00267-009-9329-1
- Pander J, Geist J (2013) Ecological indicators for stream restoration success. Ecological Indicators 30: 106–118. https://doi.org/10.1016/j.ecolind.2013.01.039
- Pander J, Geist J (2018) The contribution of different restored habitats to fish diversity and population development in a highly modified river: A case study from the river Günz. Water (Basel) 10: 1202. https://doi.org/10.3390/w10091202
- Pander J, Knott J, Mueller M, Geist J (2019) Effects of environmental flows in a restored floodplain system on the community composition of fish, macroinvertebrates and macrophytes. Ecological Engineering 132: 75–86. https://doi.org/10.1016/j.ecoleng.2019.04.003
- Peipoch M, Brauns M, Hauer FR, Weitere M, Valett HM (2015) Ecological simplification: Human influences on riverscape complexity. Bioscience 65: 1057–1065. https://doi.org/10.1093/biosci/biv120
- Perry D, Harrison I, Fernandes S, Burnham S, Nichols A (2021) Global analysis of durable policies for free-flowing river protections. Sustainability 13(4): 2347. https://doi.org/10.3390/su13042347
- Petts GE, Moeller H, Roux AL (1989) Historical change of large alluvial rivers: Western Europe. https://www.osti.gov/biblio/5630431
- Poff NL, Zimmerman JK (2010) Ecological responses to altered flow regimes: A literature review to inform the science and management of environmental flows. Freshwater Biology 55: 194–205. https://doi.org/10.1111/j.1365-2427.2009.02272.x
- Poff NL, Allan JD, Bain MB, Karr JR, Prestegaard KL, Richter BD, Sparks RE, Stromberg JC (1997) The natural flow regime. Bioscience 47: 769–784. https://doi.org/10.2307/1313099
- Ramos V, Formigo N, Maia R (2017) Ecological flows and the water framework directive implementation: An effective coevolution. European Water 60: 423–432. https://www.ewra.net/ew/pdf/EW_2017_60_58.pdf
- Rinaldi A (2021) Biodiversity 2030: a road paved with good intentions: The new EU Commission's biodiversity Strategy risks to remain an empty husk without proper implementation. EMBO Reports 22: e53130. https://doi.org/10.15252/embr.202153130
- Rodriguez-Iturbe I, Rinaldo A (1997) Fractal river basins: chance and self-organization. Cambridge University Press. https://doi.org/10.1063/1.882305
- Rouillard J, Meier J, Blackstock KL, Matthews KB, Birk S (2026) Does the Common Agricultural Policy 2023–2027 support the restoration of freshwater ecosystems? In: Kaden US, Schmid S, Wulf S, Marsden K, Klusmann C, Bonn A, Tockner K, Scholz M (Eds) Wetlands in a Changing Climate: Restoring Coasts and Floodplains. Nature Conservation 62: 337–354. https://doi.org/10.3897/natureconservation.62.148845
- Sarker S, Veremyev A, Boginski V, Singh A (2019) Critical nodes in river networks. Scientific Reports 9: 11178. https://doi.org/10.1038/s41598-019-47292-4
- Schwarz U (2020) Hydropower Projects on Balkan Rivers - 2020 Update. RiverWatch EuroNatur, 33 pp. https://balkanrivers.net/uploads/files/3/Balkan_HPP_Update_2020.pdf
- Serra-Llobet A, Jähnig SC, Geist J, Kondolf GM, Damm C, Scholz M, Lund J, Opperman JJ, Yarnell SM, Pawley A, Shader E, Cain J, Zingraff-Hamed A, Grantham TE, Eisenstein W, Schmitt R (2022) Restoring Rivers and Floodplains for Habitat and Flood Risk Reduction: Experiences in Multi-Benefit Floodplain Management From California and Germany. Frontiers in Environmental Science 9: 778568. https://doi.org/10.3389/fenvs.2021.778568
- Smith LC (2020) Rivers of power: how a natural force raised kingdoms, destroyed civilizations, and shapes our world. Penguin, UK.
- Stammel B, Cyffka B, Geist J, Müller M, Pander J, Blasch G, Fischer P, Gruppe A, Haas F, Kilg M, Lang P, Schopf R, Schwab A, Utschik H, Weißbrod M (2012) Floodplain restoration on the Upper Danube (Germany) by re-establishing water and sediment dynamics: A scientific monitoring as part of the implementation. River Systems 20(1–2): 55–70. https://www.academia.edu/download/42329534/Floodplain_restoration_on_the_Upper_Danu20160207-26127-1n01bun.pdf
- Stammel B, Jähnig SC, Mehl D, Pusch M, Srđević Z, Tschikof M, Wulf S, Scholz M (2026) Assessing ecosystem services across scales to support nature-based solutions in river floodplains: a review of non-monetary tools. In: Kaden US, Schmid S, Wulf S, Marsden K, Klusmann C, Bonn A, Tockner K, Scholz M (Eds) Wetlands in a Changing Climate: Restoring Coasts and Floodplains. Nature Conservation 62: 95–119. https://doi.org/10.3897/natureconservation.62.148716
- Stoffers T, Collas F, Buijse A, Geerling G, Jans L, Van Kessel N, Verreth J, Nagelkerke L (2021) 30 years of large river restoration: How long do restored floodplain channels remain suitable for targeted rheophilic fishes in the lower river Rhine? The Science of the Total Environment 755: 142931. https://doi.org/10.1016/j.scitotenv.2020.142931
- Stoffers T, Buijse A, Geerling G, Jans L, Schoor M, Poos J, Verreth J, Nagelkerke L (2022) Freshwater fish biodiversity restoration in floodplain rivers requires connectivity and habitat heterogeneity at multiple spatial scales. The Science of the Total Environment 156509. https://doi.org/10.1016/j.scitotenv.2022.156509
- Stoffers T, Altermatt F, Baldan D, Bilous O, Borgwardt F, Buijse AD, Bondar‐Kunze E, Cid N, Erős T, Ferreira MT (2024) Reviving Europe's rivers: Seven challenges in the implementation of the Nature Restoration Law to restore free‐flowing rivers. Wiley Interdisciplinary Reviews. Water (Basel) 1717. https://doi.org/10.1002/wat2.1717
- Ten Brinke W (2005) The Dutch Rhine: a restrained river. Veen Magazines.
- Thieme M, Birnie-Gauvin K, Opperman JJ, Franklin PA, Richter H, Baumgartner L, Ning N, Vu AV, Brink K, Sakala M (2023) Measures to safeguard and restore river connectivity. Environmental Reviews. https://doi.org/10.1139/er-2023-0019
- Tockner K, Stanford JA (2002) Riverine flood plains: Present state and future trends. Environmental Conservation 29: 308–330. https://doi.org/10.1017/S037689290200022X
- Tockner K, Ward JV, Arscott DB, Edwards PJ, Kollmann J, Gurnell AM, Edwards PJ, Kollmann J, Gurnell AM, Petts GE, Maiolini B (2003) The Tagliamento River: A model ecosystem of European importance. Aquatic Sciences 65(3): 239–253. https://doi.org/10.1007/s00027-003-0699-9
- Tonkin JD, Stoll S, Sundermann A, Haase P (2014) Dispersal distance and the pool of taxa, but not barriers, determine the colonisation of restored river reaches by benthic invertebrates. Freshwater Biology 59: 1843–1855. https://doi.org/10.1111/fwb.12387
- Truchy A, Csabai Z, Mimeau L, Künne A, Pernecker B, Bertin W, Pellizzaro F, Datry T (2023) Citizen scientists can help advance the science and management of intermittent rivers and ephemeral streams. Bioscience 73(7): 513–521. https://doi.org/10.1093/biosci/biad045
- Van de Bund W, Muehlmann H, Ofenboeck G, Schmitt K, Schultze A, Bussettini M, Peruzzi C, Parasiewicz P, Belka K, Calleja B, Magdaleno G, Bartkova T, Goltara A, Reckendorfer W, Christiansen T, Isid D, Bastino V (2024) BDS2030: Criteria for identifying free-flowing rivers for the EU Biodiversity Strategy. European Commission Ispra. https://doi.org/10.2760/402517
- Van Looy K, Tonkin JD, Floury M, Leigh C, Soininen J, Larsen S, Heino J, LeRoy Poff N, Delong M, Jähnig SC (2019) The three Rs of river ecosystem resilience: Resources, recruitment, and refugia. River Research and Applications 35: 107–120. https://doi.org/10.1002/rra.3396
- Van Puijenbroek PJ, Buijse AD, Kraak MH, Verdonschot PF (2019) Species and river specific effects of river fragmentation on European anadromous fish species. River Research and Applications 35: 68–77. https://doi.org/10.1002/rra.3386
- Vári Á, Podschun SA, Erős T, Hein T, Pataki B, Iojă I-C, Adamescu CM, Gerhardt A, Gruber T, Dedić A (2022) Freshwater systems and ecosystem services: Challenges and chances for cross-fertilization of disciplines. Ambio 51: 135–151. https://doi.org/10.1007/s13280-021-01556-4
- Villéger S, Blanchet S, Beauchard O, Oberdorff T, Brosse S (2011) Homogenization a of the world's freshwater fish faunas. Proceedings of the National Academy of Sciences of the United States of America 108: 18003–18008. https://doi.org/10.1073/pnas.1107614108
- Ward JV (1989) The four-dimensional nature of lotic ecosystems. Journal of the North American Benthological Society 8(1): 2–8. https://doi.org/10.2307/1467397
- Ward JV, Stanford J (1995) The serial discontinuity concept: Extending the model to floodplain rivers. Regulated Rivers 10: 159–168. https://doi.org/10.1002/rrr.3450100211
- Ward JV, Tockner K, Edwards PJ, Kollmann J, Bretschko G, Gurnell AM, Rossaro B (1999) A reference river system for the Alps: the 'Fiume Tagliamento'. River research and applications 15(1–3): 63–75. https://doi.org/10.1002/(SICI)1099-1646(199901/06)15:1/3%3C63::AID-RRR538%3E3.0.CO;2-F
- Winemiller KO, McIntyre PB, Castello L, Fluet-Chouinard E, Giarrizzo T, Nam S, Baird I, Darwall W, Lujan N, Harrison I (2016) Balancing hydropower and biodiversity in the Amazon Congo, and Mekong. Science 351: 128–129. https://doi.org/10.1126/science.aac7082
- Wohl E, Brierley G, Cadol D, Coulthard TJ, Covino T, Fryirs KA, Grant G, Hilton RG, Lane SN, Magilligan FJ (2019) Connectivity as an emergent property of geomorphic systems. Earth Surface Processes and Landforms 44: 4–26. https://doi.org/10.1002/esp.4434
- Zarfl C, Lumsdon AE, Berlekamp J, Tydecks L, Tockner K (2015) A global boom in hydropower dam construction. Aquatic Sciences 77: 161–170. https://doi.org/10.1007/s00027-014-0377-0