Water governance refers to political, social, economic, and administrative systems that intend to improve water resource management [1
]; for example, promoting sustainable development of water resources and services. In an urban context, rivers have been pervasively modified for various uses and to reduce flood risks [2
]. This development has resulted in severe ecological dysfunctions described as the “urban stream syndrome”, which is characterized by flashier hydrography, elevated concentrations of nutrients and contaminants, altered channel morphology, reduced biotic richness, and increased dominance of tolerant species [4
]. River restoration aims to re-establish ecological functions of running water ecosystems [5
]. According to the definition formulated by Clewell [7
] a broad spectrum of restoration activities, e.g., rehabilitation, reclamation, and revitalization, are gathered under the term “restoration” and differ in their ecological quality goals. Urban river restorations (URR) generally need to integrate ecological goals, physical constraints [8
], flood protection for close-by areas, as well as increasing demands for recreational uses by citizens [9
]. URR are motivated by multiple ecological and societal drivers, especially (a) governmental interventions setting new requirements of legislations and laws, such as the ecological quality goals demanded by the Water Framework Directive [11
]; and (b) citizens’ increasing demands for a better quality of life, e.g., improvement of the recreational potential of the riverine area [11
]. While many urban river restoration projects have been initiated [13
], a review of published articles from the Web of Knowledge carried out by Francis [15
] showed that scientific studies on urban freshwater body restorations remain rare, especially in the case of major cities. However, the publication of feedback is an important issue to fertilize restoration governance, sciences, and practices. When studies on URR exist, they focused on the success of the restoration in terms of ecological recovery [16
] and chemical quality improvement [15
]. Little concern has been given to societal aspects [17
], e.g., how social, cultural, recreational, political, and historical contexts influence water governance and practices in the case of urban river restorations.
The European water governance took, in 2000, a decisive turn with the signature of the Water Framework Directive (WFD). The WFD is one of the most ambitious environmental legislations [12
] and intends to ensure a good ecological quality [21
] of all water bodies inside the European Union, considering biological, hydro-morphological, and chemical characteristics. However, the European political landscape is heterogeneous. Authorities in each European member state incorporate rights and obligations of European directives into their own law. Historic-cultural differences are important inside Europa and each country has developed in the past its own policies for slightly different purposes [22
]. Hence, Europe showed a wide variation of water governance, e.g., policies, before and after the WFD came into force [20
]. This background suggests that, despite the fact that the WFD is a powerful tool, it may differently influence the national water governance failing in homogenizing the restoration effort. The understanding of the country-specific differences of water governance may help to cross-fertilize systems, and to formulate effective E.U. policies.
Cross-national comparative research is an effective tool to understand different societal responses to common issues [26
], and to cross-fertilize knowledge [27
]. This study investigates the variability of URR in different policy and cultural contexts by choosing the cases of projects in major cities in France and Germany to (a) cross-fertilize knowledge; and to (b) investigate the influence of macro-level water governance on micro-level restoration practices in these European countries. The comparison between France and Germany is particularly interesting since they both have a long-standing tradition of restoration and, therefore, a large number of projects. Furthermore, they developed in the past similar strategies in environmental policies as, for example, in flood risk reduction [22
]. However, major differences exist. First, a Europe-wide comparative study showed that fundamental parts of landscape planning policies and landscape approaches differ between France and Germany [28
]. German approaches are usually more ecologically-oriented than French, which underscore human needs and usages. Social concerns and cultural understanding of nature also differ between both countries [26
] and influenced the formulation of planning strategies, as well as the design and management of urban green spaces [31
]. Studies showed that, in France, citizen preference for controlled nature is higher than in Germany, where urban parks have a more natural design comparing, for example, major parks in Paris and Berlin [30
]. Since urban riverine areas are commonly used as urban green spaces, urban river restoration practices may also mirror this difference of nature preferences. Accordingly, we expect to find, in France, restoration projects of the “rehabilitation” type, according to the definition formulated by Clewell [7
] namely focusing on the reestablishment of ecosystem processes, productivity, and services, whereas German projects may target a more ecologically-oriented river restoration. Additionally, water governance prior signature of the WFD differed between the countries, e.g., concerning water quality control policies [23
], and different river management and planning strategies [20
]. These differences may have contributed to the achievement of different river ecological status at the date of the ecological inventory of European freshwater in 2004 [35
]. Different river status in the past may influence the current river restoration strategy. The understanding of country-specific and historical-cultural influence on the restoration practices may provide valuable information for further development of the water governance strategy avoiding disconnection between policy, practices, and governance.
Accordingly to this background, this study aims to investigate the limit of the common framework caused by the influence of socio-cultural drivers on national water governance by comparing urban river restoration projects in France and Germany. We hypothesized that, despite a common framework orchestrating the ecological restoration of the European rivers, between both investigated countries: (1) the driving forces for the restoration effort, e.g., the influence of the WFD, differ; (2) the restoration approaches differ, namely, that the German approach may be more ecologically-oriented than the French, which may be more human-oriented, mirroring higher preferences for nature-control; and (3) antecedent conditions influence different restoration strategies.
The investigation of the restoration driving force (hypothesis 1) showed major differences between the countries. French and German authorities restored their rivers with the same intensity (between 50% and 60% of the FURR and GURR). Most of the projects (>80%) in both countries were implemented after 2000, the date of signature of the WFD. However only 45% of the projects were initiated to implement the WFD. Differences between countries existed with regard to most variables and are summarized in Table 2
. The most frequent project motivation in Germany was the implementation of the WFD (60%), while the desire for a better quality of life for the citizens was the most declared motivation in France (55%) (Figure 2
). Accordingly, measures intending to improve the recreational potential and the integration of the river into the city are more often implemented in France than in Germany (Table 2
), i.e., planting of recreational grassland (52% of the FURR against 15% of the GURR), creation of playgrounds (58% of the FURR against 22% of the GURR), improvement of the river accessibility for recreational users (87% of the FURR against 30% of the GURR). Before the WFD came into force, few projects had been implemented in both countries: n
= 5 in France and n
= 8 in Germany. However, already at this time, an important part of GURR were initiated to improve the ecological status of the rivers (50%), whereas this motivation was mentioned only once in France. Textual analysis on the project descriptions also showed that communications about projects in Germany referred more often to the term “restoration” and the WFD than communications about French projects (51.2% of GURR against 12.5% of FURR).
The comparison of the understanding of the restoration approach between the countries (hypothesis 2) showed that the French approach is broader than the German approach, which focuses on the ecological improvement according to the WFD. The comparison of the terms used in the project title showed that the word “restoration” was the most frequent in Germany (51.2% of the projects, n
= 22) whereas, in France, the diversity of terms was higher, e.g., reclamation (18.7%, n
= 6), restoration (12.5%, n
= 4), and rehabilitation (9.4%, n
= 3). The analysis of word co-occurrences on the short project descriptions showed that, in France, the relationship between the city (used for 46% of the projects) and the river (used for 75% of the projects) is meaningful with a co-occurrence for 32% of the projects, whereas in Germany the terms WFD (used for 50% of the projects), restoration (used for 42% of the projects), and ecological (used for 35% of the projects) are the most frequent terms of the project descriptions and have a high degree of co-occurrence (46% of the projects). The investigation on the relationship between the project title and the implemented measures showed that: (a) in both countries, projects labelled “restoration” implemented similar measures and with similar frequency (Figure 3
). For example, French and German projects labelled “restoration” intend to improve physical habitats by reestablishing (i) near-natural patterns of the river hydromorphology through artificial bank removal, embankment remodeling, and bed expansion; and (ii) the longitudinal connectivity through river bed glide removal and construction of fish friendly solution, such as ramps and fish passes; (b) the main differences between projects in France and Germany concerned projects with title other than “restoration”, e.g., rehabilitation. French projects not labelled “restoration” significantly differed from French projects labelled “restoration” and German projects. The difference between the German projects labelled “restoration”, or not, is less significant than in France. The differences concern ecological and social measures.
The investigation of different antecedent morphological conditions between the countries (hypothesis 3) was conclusive. The morphological pattern of the rivers prior to restoration differed with regard to two characteristics (Table 2
): the straightened river channel and the existence of highways or national roads along the riverbanks. German rivers were straighter than French rivers (83% of the restored urban river sections in Germany against 60% in France) and highways more often bordered restored river sections in France (50%) than in Germany (6%). Removal of roads at the riverside as part of URR was not significantly more frequent in France than in Germany. The analysis of the short project descriptions showed that the relationship between citizens and their rivers is an issue in France (46%), but not in Germany.
The objectives of this study were to provide a detailed account of the French and German urban river restoration efforts, comparing projects in both countries and focusing on their political and socio-cultural drivers. Our results showed that: (a) in both countries, the urban river restoration effort is partly driven by EU policy, but with different intensity; (b) the understanding of the restoration approach in both countries is similar, but differs for projects that are not labelled as restoration; and (c) historical relations between citizens and their rivers highly influence the restoration strategy and consequently practices.
The WFD is one of the most ambitious environmental EU policies and is a driver of the European restoration effort and river governance [12
]. The WFD intends to homogenize the EU water policy and demands to protect and/or restore all EU water bodies. France and Germany qualified the demands of the WFD as obligations of results [47
]. However, the study showed that the influence of the WFD on the restoration practices is limited. In particular, in France, where only a quarter of the URR has been directly motivated by the implementation of the WFD, the improvement of the quality of life for citizens was the most frequent project motivation. This finding shows a disconnection between macro-level policy and micro-level governance and practice. However, despite the fact that Aradóttir [11
] stated in the case of Iceland, that policies have limited impact on restoration practices and governance, the WFD seems to be a great value to set ecological standards of the European restoration effort. The study showed that, despite this common framework, both countries developed different URR practices and approaches underscoring the strength of micro-level societal drivers. German URR is ecologically oriented, as defined by the WFD, which places aquatic ecology in the center of river restoration [12
]. In France, the restoration approach is understood more broadly and projects were both ecologically and societally oriented. The differences between the countries may have several socio-cultural reasons and indicate the importance of national contexts.
First, according to a Europa-wide comparative study of landscape planning policies and landscape approaches [28
], our results showed that the German urban river restoration approach focuses more on ecological improvement than French projects, which are more comprehensive. Germany is, historically, an industrialized country with high population density [26
] and related pollution problems. The Sandoz Industry disaster (1986) causing major pollution of the Rhine River initiated in Europe, and more particularly in Germany, changes of environmental perception and governance strengthening policy for nature conservation and (river) restoration [48
]. According to this background, the German ecological river restoration trend was initiated long before the WFD came into force, for instance, with the emblematic Project Emscher restoration (1992–2020) [49
]. This circumstance may explain why German water governance is particularly related to an ecological approach similar to the one formulated by the WFD. This finding underscores the difficulties of changing water governance trends as also described in the Philippines [51
Second, previous study showed that recreational demands are, since the 1990s, increasingly important motivations of restoration [11
]. Citizens value the benefits of urban green spaces according to various subjective parameters, such as their perception of the area [29
]. However, a comparative study between France and Germany showed that nature perceptions of city-dwellers differ between both countries in their preference for nature-control, namely, that it is higher in France than in Germany [30
]. As expected from this background we found that French URR implemented measures quite well for the improvement of the recreational potential via man-made recreational facilities (e.g., playgrounds) in comparison with German URR. On the contrary, measures, such as the keeping of deadwood, at the river banks could not be observed in France, probably because it did not fit with the perception of a well-kept urban landscape. We assume that, in the context of socio-ecological change perceptions of nature, may evolve apace and that educational work should guide perception changes, ensuring public support to ecologically-oriented projects.
Third, urban-crossing rivers have social values beyond the ecological [52
]. The emotional and spiritual relationship between human beings and the rivers impact the governance and drivers of river conservation and restoration [9
] . We suggest that the historical relation between citizens and their rivers influenced the project motivation and related implemented social measures. This can be evidenced by the morphological development of the river. We found that French and German urban rivers had similar morphological status prior to restoration. The single significant difference between the restored urban river sections in these countries was the more frequent existence of urban express road or highways on the riverbanks in France. Urban highways have been built in Europe, as in post Second World War North America, during the auto city trend using vacant plot of land [53
]. German urban riversides are relatively free from urban highways, in comparison with France, even if exceptions exist. While the French state owned the major part of the urban riverside that offers a convenient plot of land for the urban highway construction [54
], neglecting social and ecological values of the river, construction of most of the German major cities infrastructure benefited from the tabula rasa caused by U.S. bombing during the Second World War, offering vacant plots of land [55
]. Interestingly, the four German URR of our sample bordering an urban highway, i.e., Saarbrücken, Siegen, Darmstadt, and Frankfurt am Main, are outliers of the German trend and have been initiated to improve the quality of life for citizens, much like most of the French URR. The finding suggests that the existence of highways on the riverside strongly influences the ecological and social restoration potential. However, we found that highways have not been removed during the restoration process. This is understandable considering that the URR stakeholders are mainly local or regional, whereas the highway removal can only be decided by national authorities.
Our study presents an original dataset of URR, a group of river restoration projects previously underrepresented in national, as well as European databases, and in publications. The extensive survey and the high participation rate led to a high significance of our results. However, we cannot definitively affirm that studied societal drivers, i.e., political and socio-cultural, alone accounted for country specific restoration trends. Other drivers or other unknown variables may also have contributed to this effect. Finally, according to the goals of the study, we presented an overview of the trends. Exceptions exist in the dataset.
This study explored the influence of some societal drivers, i.e., political and socio-cultural, on the urban river restoration trends in France and Germany. We found that the WFD assures an ecological standard and the same understanding of river restoration in Europe, but drives with more intensity urban river restoration efforts in Germany than in France. The study showed that micro-level drivers still overtake E.U. policy. The differences of practices between the countries may have several socio-cultural reasons and indicate the importance of considering national and local contexts to avoid disconnection between policy, practices, and governance.
First, our results highlighted the historical ecologically-oriented water governance in Germany. However, even if the French urban river restoration effort is more often motivated by the improvement of the quality of life for citizens than by the implementation of the WFD, ecological improvements are still a major concern.
Second, national urban river restoration trends mirror different relationships between humans and nature. Understanding the implications of city dwellers’ perceptions and expectations for urban open space planning is an important issue to estimate public endorsement, orchestrate public participation, support educational work, and ensure coherence in the water governance strategy.
Third, previous water governance strategies indirectly, but strongly, drive the current river restoration effort. Reversing historical morphological changes and restoring social and ecological functions need cooperation between stakeholders working in different agencies and government.
Taken together, our findings demonstrated that, despite powerful European legislation, the urban river restoration efforts still maintain strong national specificities. The study demonstrates that socio-cultural differences challenge the unity of E.U. water governance. Despite common requirements for ecological quality of the freshwater bodies within the European Union, the variation of societal driving forces and other contextual conditions would make it difficult if not impossible to develop a “silver bullet” approach for urban river restoration. However, a comparison of projects based on rigorous analytical frameworks, as initiated with this study, is helpful for supporting further development of guidelines for urban river restorations.