Introduction

The dynamic and shifting border between land, water, and in-between places such as tidal marshes and tidal flats make the Elbe estuary and the wider Wadden Sea landscape a unique, volatile, and muddy environment (Döring et al. 2021; Fischer 2014a, 2014b; Gustafson 2020; Hein and Thomsen 2022, Nuhn et al. 1983; Jones 2011). Different regional powers, independent marshland farmers, and the modern German state sought to stabilize and territorialize this amphibian space, where life has been structured by the tidal rhythm and by regular and sometimes devastating storm surges. Land reclamation, dredging, and the construction of a dyke system and other coastal protection measures have been employed to tame and civilize (Fischer 2014a) the estuary and the Wadden Sea. These measures allowed the permanent cultivation of marshland, the expansion of settlements and ports, and the safe navigation of increasingly large ships. These hydrological interventions transformed the Elbe estuary into a “standardized environment” (Carse and Lewis 2017) ready for port use and shipping. However, despite centuries of attempts to stabilize and standardize estuaries, hydrological conditions constantly change and remain a permanent challenge for shipping and coastal protection. Such dynamic and volatile conditions and growing vessel sizes pose serious hydrological and economic risks for estuarine ports. The most common adaptation measure is permanent maintenance dredging to keep navigation channels at a certain depth and to deepen navigation channels regularly to accommodate larger vessels. If the largest vessel classes are not able to call at a port, it may lose important customers and competitive advantages against adjacent ports. Consequently, ports have to dredge and to “grow or die” (Nogué-Algueró 2020). In particular, the “grow or die” logic builds on the permanent spatial expansion at land and sea, as more and more space is required for the disposal of dredged material below water and on land as well as for terrestrial port infrastructure such as container terminals.

We suggest that port expansion and the maintenance of existing navigation channels transform and territorialize apparently empty estuarine spaces on water and land. The interventions go hand in hand with significant regulatory changes that open up new forms of use (e.g. sediment disposal, shipping, container terminals), terminate old forms (e.g. fishing, agriculture, aquaculture), and provide the framework conditions for new profit opportunities (e.g. dredging, ecosystem restoration) (Choi 2020; Grydehøj, 2015; Hein and Thomsen 2022, Lahiri-Dut 2014; Parikh 2021). We consider the power-laden material transformations of the estuarine landscape and associated regulatory changes as specific territorialization processes that produce flourishing urban centres and port zones, and marginalized and jeopardized peripheries. Building on urban political ecology, we assume that port- and shipping-related forms of territorialization in the Elbe estuary and beyond are embedded in and the result of “socio-metabolic processes.” Following Swyngedouw (2006: 24), socio-metabolic processes “[fuse] together physical dynamics with the social regulatory and framing conditions set by the historically specific arrangement of the social relations of appropriation, production, and exchange.” In the case of port cities such as Hamburg, socio-metabolic processes are relevant on two different scales. First of all, the port serves as a metabolic gateway for the import and export of materials. Second, and more important for this article, is the “sediment metabolism” (Gustafson 2020) of port- and shipping-related forms of territorialization. The notion of the sediment metabolism stresses the fundamental importance of sediment dredging not only for maintaining navigation channels and access to ports but also for creating artificial land for terrestrial port infrastructure.

In this paper, we take the Elbe estuary and the port of Hamburg in northern Germany as an example to show how the dynamic materialities of estuarine spaces and hydrological interventions to expand and maintain a functional port, produce a specific form of territoriality at water and land. Our contribution literally follows the sediments dredged from the estuary and dumped on land and water to explain territorialization and the production of estuarine peripheries. By following sediments, we illustrate that the making of ports not only transforms the port district itself but transforms the political ecologies of the entire estuary. We focus, first, on the historical dimensions of the territorialization and material transformation of the Elbe estuary. Second, we focus on the expansive logic of dredging and disposal of sediments and the associated sediment metabolism. Third, we point to the production of estuarine peripheries by following sediments. We focus, in particular, on the marshland village of Hamburg-Moorburg, located in the port expansion zone and a major dumping ground for toxic sediments. We limit our analysis to the estuarine space and therefore build on the notion of estuarine territorialization and do not take the wider hinterland relations of ports associated with the transport of goods into account.

We build on urban political ecology and the notion of “terraqueous territoriality,” outlined by Campling and Colas (2018), to develop our approach to estuarine territorialization. We develop our argument based on information we gathered through research in historical archives, an analysis of newspaper articles and planning documents, and qualitative interviews with residents of Hamburg-Moorburg, members of political parties, NGOs, and state authorities. Our analysis contributes to the small but growing body of critical research on dredging and port management and conflict (Carse and Lewis 2017; Couling and Hein 2020; Gustafson 2020; Jaffee 2015; Lewis and Ernstson 2019; Carse and Lewis 2020; Nogué-Algueró, 2020; Pearson et al. 2016; Teschner 2019) and provides new insights into how “historical geometries of social power” (Lewis and Ernstson 2019: 4) have shaped the estuarine landscape. We further seek to go beyond approaches used in port and transport geography, which often focuses on the line that divides “city” and “port” (Delphine et al. 2019; Lieber 2018) and on the competitiveness of ports and port systems (Notteboom 2016). Instead of considering the estuary, its water bodies, islands, marshes, and tidal flats solely as an “operating environment” (Smith-Godfrey 2016: 3) or a “resource space and frontier” (Midlen 2021), as assumed in blue economy perspectives, we look at port expansion through a terraqueous territorial lens, allowing us to investigate the contested appropriation and material transformation of land and waterbodies. In addition, our article seeks to contribute to a number of recent endeavours to go beyond a land-based perspective on territory (Campling and Colas, 2021; Peters et al. 2018; Satizábal and Batterbury 2018). As Peters and colleagues (2018: 4) rightly argue, “a land based perspective on territory limits our understandings of both power and nature” To frame a “waterway” and a port as a “territory” might not be obvious in the first place. But from our perspective, and building on Carse’s (2014) work on the Panama Canal, Lewis and Ernston’s (2019) on the Mississippi Delta, and Steinberg’s (2001) on the social construction of the ocean, we consider maritime waterways and land-based port infrastructure as vast spatial infrastructures that produce “environments” bound to certain authorities, regulations, borders, and processes of inclusion and exclusion, and hence territories.

The Elbe estuary has always been a space of constant change. However, since industrialization, the pace of change has increased significantly and has induced fundamental transformations, affecting the entire region. From the eighteenth century onwards, the city expanded the landside port infrastructure, dredged new port basins, and deepened the navigation channel to adapt to increasing vessel sizes. In order to achieve their goals, the city of Hamburg, its merchants and the port industry expanded their influence on the estuary through land transactions with neighbouring duchies and the Danish King, through agreements with Prussia, the Weimar Republic, the Nazi regime (e.g. Greater Hamburg Law from 1938), and the Federal Republic. The expansion of the port transformed wetlands and the marshes previously used for agriculture and housing (such as Altenwerder, Waltershof and Neuhof) into port areas (Markert und Meinicke 1995; Nuhn et al. 1983). In addition, coastal protection measures established a more permanent border between land and water spaces, while continued hydrological interventions blocked or changed the course of river arms and established a navigation channel 17.40 m below mean sea level after the last deepening in 2021.

Our article continues as follows. First, we introduce our urban political ecology approach towards estuarine territorialization. Our approach stresses the relations between territorialization and the volatile material conditions of the estuary and the complex metabolisms of the navigation channel. Second, we provide a short introduction to methods and the study area. Third, we provide an overview on the transformation of materialities of the estuary and associated processes of estuarine territorialization. Fourth, we focus on the sediment metabolism and the associated production of peripheries in the Elbe estuary and struggles of resistance. We close our contribution with a discussion and a short conclusion, stressing the need to go beyond binary land–water conceptualizations of territory when investigating the social production of power-laden estuarine landscapes.

Urban political ecology of estuarine territorialization

Our urban political ecology of estuarine territorialization seeks to denaturalize estuaries as port locations and stresses the importance of in-depth historical and qualitative perspectives to explain environmental change in regions where the current industrialized shape of coasts, estuaries, and deltas and their evolution remains often unquestioned. Before we outline our framework, we will first situate our work within current debates in political geography and urban political ecology on territory, territorialization, and territoriality.

We define territory as a “political technology,” which includes mechanisms to control, regulate, and measure space (Elden 2010). Territorialization as a process goes hand in hand with the development of new regulatory mechanisms, narratives, authorities, and changes in the hydrology and morphology of the coast (Boelens et al 2016; Hein et al. 2020; Rasmussen and Lund 2018; Rodríguez-de-Francisco and Boelens 2016; Satizábal and Batterbury 2018). In Rasmussen and Lund’s words, it is “a strategy of using bounded space for particular outcomes, a resource control strategy” (Rasmussen and Lund 2018: 388). In our case, the main resource is the Elbe estuary as such and the possibility to use it as a waterway. Territoriality, following Elden, is a “condition or status of territory” and suggests that “territory […] is logically prior to territoriality” (Elden 2019: 803). To legitimize territorialization, space, no matter whether land, ocean, or different kinds of in-between spaces, such as tidal wetlands, has often been politically framed as empty, as civilized wilderness or as unproductive (Fischer 2014a; Fold and Hirsch 2009; Satizábal and Batterbury 2018; Tsing 2005). Following Brighenti (2010: 53), we consider territory as a set of practices that helps to organize (in our case) human-estuary relations and the associated “economy of objects and places” (Brighenti 2006: 75). In our case, this refers to the framework conditions of the port economy, namely a shipping channel that allows large vessels to call at the port, port basins, landside infrastructure and coastal protection. Despite such analogies across different materialities, fundamental differences between terrestrial and marine (including estuarine) territorialization exist and require a reconceptualization of territory and territoriality in maritime contexts, in particular, for investigating port geographies (Campling and Colás; 2021; Peters et al. 2018; Satizábal and Batterbury 2018).

First, the probably most obvious difference of aquatic and estuarine forms of territoriality are material. Water and tidal-influenced coastal in-between places are much more volatile and dynamic than their terrestrial counterparts. Campling and Colás (2018) use the term “terraqueous territoriality,” defined as “the distinctly capitalist articulation of sovereignty, territory and appropriation in the capture and coding of maritime space” (ibid. 777). In their seminal book “Capitalism and the Sea,” they point to material and physical properties of the sea which “demand a high price for [the] subordination of natural forces” (Campling and Colás: 2021: 14). Satizabal and Batterbury (2018: 62) argue that “territorialization at sea [is] particularly complex” and criticize Eurocentric notions that build mostly on clear demarcations (UNCLOS) and binary oppositions between water and land (ibid. 66). Estuarine spaces are even more complex in this regard, as the aquatic environment of the Elbe estuary, for example, is characterized by large in-between water and land zones consisting of tidal flats, tidal swamps and marshes, and shifting zones of shallow and deep water. The tidal rhythm produces a complex space where the boundaries between (permanent) land, flood prone tidal marshes, tidal flats, and shallow and deep water are constantly changing (Choi 2020; Hein and Thomsen 2022; Jones 2011).

Second, human entanglements with the aquatic environment differ from land-based ones and have received less attention by scholars but also by planners and policy makers (Oslender 2019: Satizábal and Batterbury 2018). Oslender (2019: 1697), for example, stresses the “particular assemblage of spatial relations that results from human entanglements with an aquatic environment.” Based on long-term research on Northern Germany, Fischer (2014a,b) argues that the dyke is a central element structuring landscapes, deeply infused with and reflecting social, cultural, and power relations among people, regional authorities, the emerging modern state, and the North Sea. In his work on the Colombian Pacific coast, Oslender (2019) points to river networks, mangroves, and tidal range, and to specific practices such as human mobility, livelihood patterns, and forms of socio-spatial organization structured by the tidal rhythm and river systems. Moreover, social practices taking place on open water, such as shipping and fishery for example, are as well strongly influenced by the tidal rhythm, weather conditions, seasonality, and shifting water depths (Campling and Colás, 2021: 13; Hein and Thomsen 2022). Moreover, as we sketched above, the estuary and the ocean is not an empty and static space (Satizábal and Batterbury 2018). However, as on land, territorialization reflects power relations and powerful actors seek to ignore, negate, or devalue pre-existing territorial orders, forms of social organization, authorities, and use patterns (Rasmussen and Lund 2018). In our case, for example, the ability of the port industry to handle larger vessels competes with pre-existing estuarine use and practices such as marshland agriculture and fishing (Hein and Thomsen 2022).

Third, estuarine territorialization for the sake of shipping and port development requires constant, complex, and costly hydrological interventions. In particular, the maintenance and expansion of the navigation channel requires permanent maintenance dredging and regular deepening and widening of channels to accommodate larger vessel classes. Consequently, we suggest, based on Heynen (2006) and Gustafson (2020), that estuarine territorialization is embedded in and the result of “socio-metabolic processes.” The concept of metabolism emerged in the nineteenth century, first referring to respiration and energy flows of and between organisms (Swyngedouw 2006: 22). Justus von Liebig further advanced the concept and considered all “biochemical reactions in a living thing” as being part of the metabolism (Liebig, 1840, cited in Swyngedouw 2006: 22). In the social sciences, the concept of metabolism has been introduced by Karl Marx to “describe first the human transformation of nature through labour and second the capitalist system of commodity exchange” (Wachsmuth 2012: 507). In urban political ecology, Erik Swyngedouw (1996) defines metabolism as “social and natural processes [that] combine in a historical–geographical production process of socio-nature whose outcome (historical nature) embodies chemical, physical, social, economic, political and cultural processes in highly contradictory but inseparable manners.” In our case, dredging, reclamation, coastal protection measures, tidal rhythm, and the estuary’s currents are the main socio-natural processes producing the estuary as a socio-natural space. Seth Gustafson (2020) suggests that port and shipping channels strongly rely on the “sediment metabolism.” The constant deepening and widening of shipping channels increase tidal range and tidal pumping, which further accelerates sedimentation, disturbing the metabolism and producing a metabolic rift (Boehlich and Strotmann 2008; 2019; Gustafson 2020; Hein and Thomsen 2022; Winterwerp 2013). The notion of the metabolic rift dates back to Marx as well and originally refers to interruptions of the nutrient cycles in nineteenth century agriculture (Gustafson 2020). To counterbalance the metabolic rift and following our argument to maintain and reproduce estuarine territorialization for shipping and port use, a constantly increasing amount of sediment has to be removed, requiring additional terrestrial and marine disposal sites. In addition to the continuous demand for terrestrial and marine disposal sites for sediments and land for terrestrial port infrastructure, more and more land is required for the compensation of environmental impacts. We consider such legal requirements as part of the socio-metabolic processes that maintain and permit shipping and port use. Environmental offsetting measures and the disposal of sediments are different processes, but they are both fundamental to the appropriation and territorialization of estuarine space and they involve continuous spatial expansion.

Finally, we suggest, based on urban political ecology, that socio-ecological transformation of estuarine spaces, for example by the means of dredging, dyking, and reclamation, are power-laden processes. Thus, we assume that estuarine territorialization leads to the production of uneven socio-ecological relations and flourishing ports and urban centres and neglected peripheries (Ernstson and Swyngedouw 2018; Lewis and Ernstson 2019). Estuarine peripheries, such as the toxic sediment-rinsing fields and sediment hills of Hamburg-Moorburg, have a lot in common with places framed as sacrifice zones — zones that because of human interventions entail “risks of negative impacts on human health, economic livelihood, and ways of life” (Holifield and Day 2017). Following Marcelo Lopes de Souza (2021), sacrifice zones are “from the point of view of national and international elites, with the presence of social classes and groups generally and tacitly assumed as ‘inferior’, the space converted into a sacrifice zone is regarded as particularly ‘suitable’ for receiving,” in our case loads of polluted Elbe sediments.

Methods and study area

The port of Hamburg is located approximately 120 km from the North Sea in the inner delta of the vast estuary (Fig. 1). It dates back to a first port established in the ninth century at the confluence of the tributaries Alster and Bille and the Elbe (Krieger 2006: 21) (Fig. 2) and today covers 7145 ha. This includes 4226 ha of land and 2919 ha of waterbodies. For the Hamburg Port Authority (HPA) and the Federal Waterway Agency (WSV), the Elbe estuary begins at a barrage in the town of Geesthacht in the state of Schleswig–Holstein. Since its completion in 1960, the barrage limits the tidal influence, mitigates negative impacts of dredging in the port areas (such as sinking groundwater levels), and helps to maintain inland water transport on the middle course of the Elbe (Boehlich and Strotmann 2019; WSV n.d.). The estuary and its inner delta can be considered as a vast and highly dynamic terraqueous zone (Boehlich and Strotmann 2019). The cross-section of the river, for example, changes fundamentally between low and high tide. On both sides of the shipping channel, tidal flats of sand and mud become visible during low tide and illustrate the volatile character of the land–water border. Human interventions along the estuary have changed its shape profoundly and have reduced tidal-influenced marshes (Boehlich and Strotmann 2019). Today, marsh islands of the interior delta are all protected by dykes and other coastal protection measures.

Fig. 1
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Maps of the Elbe estuary and the North Sea

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Our main land-based research location is the urban district of Hamburg-Moorburg (Fig. 1). Moorburg is a former marshland village located in the inner delta of the estuary, to the south of Hamburg’s city centre. It was initially founded as a fortification to protect the southern part of the delta and to underpin Hamburg’s claims to control the estuary (Rieck 1975). Today, the urban district is mainly a residential area with a peri-urban character. The population of the district is declining constantly. Today, the district has only 706 inhabitants (Statistisches Amt für Hamburg und Schleswig–Holstein 2020). A few farmers, mainly cultivators of fruit trees, remain in the western part of the district.

We conducted in total 12 semi-structured interviews (in 2020 and 2021, some of them via video conference tools because of the Covid-19 pandemic) with inhabitants of Moorburg, members of an association for the preservation of the church of St. Gertrud of Hamburg-Altenwerder (adjacent district, inhabitants evicted for the construction of Altenwerder Container Terminal), staff of the Hamburg Port Authority (HPA), members of political parties and staff of environmental NGOs. For the interviews with inhabitants of Moorburg, we used an interview guide of open questions on the history of the conflict with the port authority in the district, on port expansion law and its local interpretation, on individual and collective resistance strategies against the port expansion law, and on the relations people in Moorburg have with the estuary and the port. For the interviews with other actors (listed above), we focused on port policies, regulatory frameworks, port expansion plans, environmental impacts, sediment disposal, and the role of the port for Hamburg’s economy and identity. In addition, in August 2021, the first author engaged in a number of informal interviews and conversations on socio-ecological benefits and trade-offs of port expansion with coastal protection staff, a former staff member of a container terminal operator, a farmer, a wadden coachman, a mayor of a marshland municipality in Lower Saxony, and a warden of a bird reserve in Hamburg. We complemented the insights gained through interviews with a qualitative content analysis of newspaper articles on the recent fairway adaptation planning documents, port development strategies, and historical documents. Our corpus of newspaper articles covers the period from February 2017 to August 2018. This covers a period when issues of port expansion and the deepening of the navigation channel received high media attention, as the German Administrative Court rejected the planning approval decision of the latest round of deepening in February 2017 and approved the revised plans in August 2018. All interview data and documents have been coded using a software package. For the newspaper articles, we first conducted a lexicometric analysis and then coded paragraphs with information on the fairway adaptation.

Historical patterns of estuarine territorialization

Since medieval times, Hamburg has secured the connectivity of its port to global trade networks (Rohmann 2019: 208) and has emerged as the dominant political and economic centre of the lower Elbe region and an important transhipment hub for Northern Europe and the Baltic region. Hamburg established connectivity and control over the Elbe estuary by building on a diverse set of political technologies: first, by seeking to legitimize territorial claims over the estuary by reaching out to “higher” political and religious authorities (such as the Holy Roman Emperor, the Pope, the modern German state), and by the means of fraud and military force including construction of fortifications on the island of Neuwerk, in Cuxhaven (former District of Ritzenbüttel) and Hamburg-Moorburg; second, by enforcing trade rules and stacking rights to put pressure on competing ports along the estuary; third, through hydrological interventions to change watercourses, to maintain the safe navigation of ships that were growing in size and to reclaim land for agricultural production (Rohmann 2019; Stahncke n.d).

Most interesting for our argument are the hydrological interventions which changed the material shape of the estuary (Fig. 2). They had a decisive influence over the socio-spatial organization of estuarine space and were key elements of territorialization processes. Since medieval times, the ability to establish clear borders between water and land and to create or re-direct water bodies and river arms have been important manifestations of territorialization processes and power in the Elbe estuary (Rohmann 2019; Strom- und Hafenbau 1992; Fischer 2014a). They were directly associated with establishing and maintaining Hamburg as the main estuarine port. A first larger hydrological intervention in the earlier sixteenth century, for example, intended to transform the Norderelbe into the main river arm to improve navigation to Hamburg’s port and to worsen the conditions on the Süderelbe (Stahncke n.d.), limiting the accessibility of competing ports. In modern times, the mouth of the Köhlbrand stream, for example, was moved 600 m to the west to create space for the container terminal of Waltershof, and the Alte Süderelbe stream was blocked and partially filled after the storm surge of 1962 (Nuhn and Ossenbrügge 1983: 94).

Fig. 2
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Map of the inner delta in the late eighteenth century produced under the supervision of Major Gustav Adolf von Varendorf of Schleswig

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Since the sixteenth century, navigation channels have been constantly monitored, measured, and if necessary, dredged (Köster and Thies 2015). The most profound transformations have been initiated from the nineteenth century onwards. The navigation channel has undergone a process of widening and deepening, from a depth of 5.30 m in preindustrial times to its 2021 depth of 17.40 m below sea level. These interventions have been possible because of Hamburg’s ability to maintain significant influence over the estuary, including on parts belonging to Hanover, Denmark, Prussia, and later to the state of Schleswig–Holstein and Lower Saxony. In 1922, the city reached a still legally and politically relevant agreement with the government of the Weimar Republic, which stressed that “Hamburg has always maintained and adapted the waterway enabling safe access to the port for the largest vessel classes, the Reich will continue this practice” (own translation, Schneider 2019: 45). The still valid Federal Waterway Law from 1968 refers to this agreement (§12 Abs. 4 WaStrG), and until today, the Federal Government has always complied with this law and supported the maintenance and further deepening of the federal waterway Elbe.

The ability to create land from and defend land against the estuary (and other regional powers) is another important manifestation of territoriality and power in the Elbe estuary. Norbert Fischer (2014a) describes the dyke as a representation of periods of land gains through reclamation and land loss after storm surges destroy the dyke system. Land reclamation and the draining of the marshes to create additional fertile agricultural land and land for port infrastructure became important measures to expand agricultural production, port capacities, and to strengthen territorial control. In Hamburg-Moorburg, drainage and the construction of dykes began around 1300 AD and was also an attempt to expand and consolidate the political influence of Hamburg in the southern part of the interior delta. As in other marsh areas, settlers established dyke associations and jointly constructed ditches and dykes in order to comply with the existing dyke construction and maintenance obligations (Aust 1929; Fischer 2014a, 2014b; Lorenzen-Schmidt et al. 1993; Pelosse 1955).

The production of estuarine peripheries and the port metabolism

As we outlined above, we assume that port- and shipping-induced forms of estuarine territorialization lead to specific patterns of uneven development and to the associated production of centres and peripheries, which are, to some degree, related to the specific materiality of estuarine spaces. We focus our attention on the peripheries, in other words, on the marginalized spaces, the sacrifice zones, and on the socio-ecological impacts of estuarine territorialization. The metabolism of estuarine territorialization and the associated permanent need to dredge and to expand marine and terrestrial sediment disposal sites, displaces previous forms of land and marine use practices. In the following, we first focus on sediments, metabolism, and spatial expansion of disposal sites. Second, we follow the dredged sediments to Hamburg-Moorburg and shed light on resistance struggles against sediment disposal and port expansion. Moorburg is thereby an illustrative example for the many places that have to cope with the direct or indirect implications of dredging and sediment disposal at land and water.

The metabolism of maintaining the navigation channel

Federal waterways are territories that are mapped, zoned, and maintained. However, their huge volume and dynamic and fluid character makes their maintenance and their territorialization a challenging endeavour. To maintain water depths in the navigation channels and port basins, WSV and HPA have developed sediment management strategies (HPA 2022; WSV 2018). Their main approach to maintenance dredging of the estuary is the permanent relocation of sediments within the estuary. Material is dredged in one part and disposed in underwater disposal sites further downstream in locations where sediments will be further transported downstream by the ebb flow. HPA claims to build on the “natural framework conditions” of the estuary and and has to cope with the issue of “circular dredging,” which means that sediments are dredged and transported by dredging ships or the ebb flow further downstream, whereas the high tide transports sediments back into the inner parts of the estuary (HPA n.d.). These sediment management strategies lead to enormous sediment loads. In the whole estuary, HPA and WSV removed 368 million m3 of sediments between 2001 and 2019 and an additional 35 million m3 for the most recent deepening of the fairway, completed in 2022 (HPA 2022).

In 2020, 1.5 million tonnes were disposed in the North Sea (most at buoy E3, close to the island of Helgoland), 2.0 million tonnes were disposed at the state border, and 0.19 million tonnes of toxic sediments had to be disposed on land (HPA 2021b).Footnote 1 This only includes the material dredged in the section of the Elbe managed by the HPA. On land, sediments will be washed and dried, for example in the sediment-rinsing fields of Hamburg-Moorburg, and mechanically disaggregated. The resulting materials are either used for reclaiming abandoned port basins or for construction material. However, large quantities have to be stored at terrestrial disposal sites. Both rinsing fields and permanent disposal sites require a significant amount of space in the districts of Moorburg, Moorfleet, and Francop (see Fig. 1). The rinsing fields in Moorburg have a size of approximately 100 ha. The disposal site in Moorfleet, a hill of dredged sediments, is even planned to reach 56 m above sea-level. The disposal site E3 in the North Sea off Schleswig–Holstein’s coast is able to take sediment loads of up to 1.5 million cubic metres per year. The disposal site has been secured by the HPA through an agreement with Schleswig–Holstein, reached in 2016. The Ministry for Energy Transition, Agriculture, Environment, Nature and Digitalization of Schleswig–Holstein designated four “disposal centres,” virtually marked by coordinates, where sediments can be disposed of in a radius of up 1.5 km (Schleswig–Holstein 2016). According to HPA, the site permits the sustainable removal of sediments from the estuary, and comprehensive monitoring confirmed no significant impacts on the marine environment (HPA 2017, 2021a, 2022).

Rising sediment loads caused by the widening and deepening of the navigation channel (Winterwerp 2013) and reduced run off in recent years illustrate the increasing metabolic rift characterizing the Elbe estuary as a federal waterway. Consequently, HPA and WSV are constantly seeking out new disposal sites. The HPA has just completed a screening of a potential site called “Outer Elbe of Hamburg,” close to the islands of Neuwerk and Schärhorn in the estuary mouth. The site is part of the state of Hamburg, within the federal waterway and located outside the national park, the UNESCO Heritage Site, EU Flora Fauna Habitat (FFH), and bird protection areas (HPA 2022). A bird warden told us in August 2021 that the Hamburg Senate intentionally excluded the area when designating the national park in order to secure potential sediment disposal sites within the state boundaries. Other recently secured sites, such as the Medemrinne and Neufelder Sand (both in the mouth of the estuary), are considered as “win–win” measures. They should absorb the dredged sediments (15 million cubic metres will be placed in the Medemrinne) and reduce tidal pumping and sediment transport towards the inner estuary (Förderkreis Rettet die Elbe 2016; 2021; Hein and Thomsen 2022; Wattenmeer-Schutz Cuxhaven 2019). More recently, the HPA and the Hamburg Senate are further expanding their claims to ocean space by requesting approval from the Federal Government to establish new disposal sites within the Exclusive Economic Zone (EEZ) (Freie und Hansestadt Hamburg Behörde für Wirtschaft und Innovation 2022; HPA 2020).

The legal and ecological implications of dredging and below water sediment disposal are contested.Footnote 2 Those using the estuary or its water, such as fishers and farmers, need to apply to the relevant authority for a permit. However, fishing permits do not include the right to a successful catch, as the German Administrative Court has stressed in a recent court proceeding on the deepening and widening of the navigation channel of the estuary (BVerwG 7 A 1.17). In contrast to terrestrial port expansion, the adaptation of the fairway is not deemed to challenge or infringe the property of fishers nor their fishing rights. The judges argue that the planning approval decision (leading to the fairway adaptation) does not revoke any rights. The ability to benefit from rights, and potential income losses because of declining catches caused by dredging, do not have the same weight as property rights on land and, therefore, do not warrant a full review of the planning approval decision (BVerwG 7 A 1.17). The complainants include fishers using stow nets and traps in the river, coastal fishers and owners of fishing concessions further upstream (586.9 to 607.5 km, Geesthacht to Hamburg and 477 to 500 km, close to Gorleben in Lower Saxony). They argued, for example, that below-water sediment disposal areas of the Medemrinne will affect or destroy fishing grounds, and that the impacts of the entire hydrological intervention on the oxygen levels of the estuary, and therefore on marine biodiversity, have not been fully considered in the planning approval decision (BVerwG 7 A 1.17). In addition, the fishers argue that below-water sediment disposal sites will affect important shrimp habitats (Hein and Thomsen 2022). However, the court stressed that “the concerns of commercial fishers carry little weight compared to the public interests in the development of a federal waterway” (BVerwG 7 A 1.17).

Mostly uncontested is that the accelerated deepening and widening of the fairway during the twentieth century, the embankment of floodplains, land reclamation, and the barrage in Geesthacht are all causes of the increased tidal range and tidal pumping (Boehlich and Strotmann 2019; Fickert and Strotmann 2007; Winterwerp 2013), further increasing the unpredictability of the estuary. Since the beginning of the twentieth century, the tidal range at the gauge of Hamburg-St. Pauli has increased from 1.60 to 3.66 m (Fickert and Strotmann 2007; Hafen Hamburg Marketing 2022). Tidal pumping leads to the transportation of mud sediments towards the inner estuary, and stronger and shifting tidal currents cause significant erosion in the outer parts. As a result, for example, the Medemsand, a former island in the mouth of the estuary, disappeared during the 2000s.

The most recent deepening and widening of the navigation channel have been declared as failed by a number of observers, the Green Party and the mediaFootnote 3 (NDR 2022a; Förderkreis Rettet die Elbe 2023). Increased sedimentation since the completion of the intervention, in particular at the margins of the navigation channel caused by submarine sediment slides, reduced the water depth in parts of the estuary (NDR 2022a; Förderkreis Rettet die Elbe 2023). In August 2022, the rather small tanker “Sten Arnold” with a drought of only 8.5 m was stuck in mud in an area which had, according to most recent maps, a depth of 11.5 m. Investigations by the harbour police revealed that the incident was caused by an underwater sediment hill. The hill, according to the investigations, occurred because of “natural turbulences” (NDR 2022b). Moreover, the incident indicates that the recently deepened estuary is currently too dynamic to be adequately mapped, illustrating the very specific territoriality of the estuary. As a response, the federal water way agency reduced the permitted draught by 80 cm and announced additional and more coordinated dredging efforts supported by HPA (WSV 2022).

Estuarine peripheries

When arriving at the district of Hamburg-Moorburg, with its large green hills of dredged sediments and excavated material from the construction of the Container Terminal Altenwerder (CTA), lived-in and abandoned houses and well-managed and run-wild gardens, one immediately recognizes the specific character of this place. A resident told us in an interview that Moorburg is unique because “life as such is political here, it is always about port expansion, all the time […] it is the chronic disease of Moorburg, a pain in your back reminding you that things can suddenly change […].”Footnote 4 In fact, the district is an island surrounded by the above-mentioned green hills of dredged Elbe sediments, sediment-rinsing fields, the CTA, and a coal power plant. It is divided by Hamburg’s most important north–south federal highway (A7) and impacted by the construction of the new federal highway (A26) linking Hamburg with Stade.

Since 1928, Moorburg had been designated for port expansion. In 1982, based on the Port Development Law, large parts of Moorburg became classified for immediate port expansion (Zone I) or as a reserve for future expansions (Zone II), and eviction notices were distributed to residents in Zone I (Freie und Hansestadt Hamburg 1982). The Port Development law (and its predecessor the Port Expansion Law from 1961) is unique in the German context (Badura and Schmidt-Assmann 1983; Kühling 2011; Raloff 1982). Within these zones, the Hamburg Port Authority and its predecessors have pre-emption rights and are authorized to legitimize changes in land use, to organize expropriation of land, and to prepare land and water spaces for port use. The port expansion plans in the area of Moorburg included the dredging of port basins and land-based port infrastructure. As of 2022, port expansion has not materialized because of stagnating container handling, but, as hills and vast sediment-rinsing fields indicate, the district did become a major dumping site for dredged Elbe and port sediments and a site directly related to the sediment metabolism and the expansive logic of port development. The first sediment-rinsing fields were created in the 1950s, and these fertile fields were, until the 1970s, even used for agricultural production, before the high concentrations of heavy metals were discovered (Euler et al. 1982: 40). The disposal of sediments within the port expansion zone was also used to raise the land, and was considered as a preparatory step for port expansion (interview with vice-head of Strom und Hafen, cited in Euler et al. 1982: 23).

The first attempts of the Hamburg Senate to relocate Moorburg, and the first purchases of land and buildings, started after the Köhlbrand Treaty with Prussia in 1928 (Lorenzen-Schmidt et al. 1993). Land purchases continued in the post-war period. In the devastating storm surge of 1962, five citizens died in Moorburg, a large number of livestock drowned, and 16 houses were destroyed. In the aftermath, many inhabitants (in particular farmers) sold their land and left Moorburg. Some inhabitants accused the senate and port authority of not having maintained and repaired the dykes appropriately because they anticipated the district being turned into a port area.Footnote 5 We were not able to verify this claim, but the poor condition of the dykes of Moorburg was known about. They did not even fulfil the nominal height of 5.65 m, defined in 1889, and their further elevation to 6.20 m was planned just before the flood occurred (Bütow 1962; Meyer n. d). In the 1970s, the first residents of eastern Moorburg had to leave their homes for the development of an industrial park.

The port development law and its restrictions on land use in order to create opportunities to expand the port, hampered the development of Moorburg significantly. In addition, the destruction caused by the storm surge, the transformation of agricultural land to industrial use in eastern Moorburg, the construction of the railway and highways, and the expansion of the rinsing fields worsened the living conditions of the inhabitants significantly. An environmental activist and member of the Green party complained, in an article published by Der Spiegel in 1982 (Der Spiegel 1982), that the population is “deliberately demoralized” by representatives of the city. Moreover, she accused the representatives of “blackmail and threatening the inhabitants with expropriation even though there was no legal basis for doing so (own translation).”

However, some inhabitants engaged in active or passive resistance against sediment disposal and port expansion. Environmental activists moved to Moorburg to challenge the Senate’s port expansion plans, while some residents of Moorburg just continued their lives and ignored the eviction notices of the Senate.Footnote 6 In a public hearing of the Hamburg Parliament, the citizen association of Moorburg and of neighbouring Francop questioned the assumptions made by the Senate about freight growth and opposed the plans to relocate inhabitants to large housing estates (Bürgerschaft der Freien und Hansestadt Hamburg 1981). They worried that the remaining parts of Moorburg would not be used for the construction of port facilities but only for the further expansion of sediment-rinsing fields, and stressed that they would not accept the demolition of their buildings to turn Moorburg into a dump for toxic sediments. An activist and citizen of Moorburg claimed that their protest led the Senate to decide to maintain the purchased buildings and to turn them into tenements instead of destroying them years before the actual expansion (as had been done in Altenwerder).Footnote 7 A former resident of Altenwerder explained in one of our interviewsFootnote 8 that the immediate destruction of houses bought by the city turned Altenwerder into a place not worth living in and significantly reduced their motivation to resist the port expansion years before the construction of the CTA.

In January 1982, just before the new Port Development Law was adopted, environmental activists, lawyers, and members of the citizens association of Francop and Moorburg developed a highly creative form of resistance. They jointly bought a house and issued share certificates to 2000 shareholders (some of whom lived in distant places such as New York and Baghdad) to complicate any expropriation.Footnote 9 The housing project was part of a larger and emerging environmental movement in northern Germany questioning industrialization, the growth paradigm, and the expansion of the port to encompass Altenwerder and Moorburg (Nuhn et al. 1983).

Many of the rather conservative inhabitants were quite sceptical about this externally driven protest and have continued to use hidden and clandestine resistance strategies, such as strategically ignoring regulations. Representatives of local churches suggested that existing port areas should be developed when more land for container terminals was needed, instead of destroying a village, and that the only alternative was to release Moorburg from the port development area (Bürgerschaft der Freien und Hansestadt Hamburg 1981). The association of farmers in Hamburg argued that Moorburg was historical farmland, developed by generations of local farmers, and that destroying Moorburg meant destroying their livelihoods (Bürgerschaft der Freien und Hansestadt Hamburg 1981). A number of our research participants confirmed the importance of centuries-old agriculture to the marshes and the continuous “making of agricultural land” for the identity of Moorburg.Footnote 10 Two of them claimed that their families had lived there for centuries and had reclaimed the muddy marshes and constructed dykes to protect the land from regular storm surges.

Since life in Moorburg is “political,” not accepting relocation can be considered as a form of resistance. This was reflected in the activities of our research participants. A member of an established family of marshland farmers explained that many people in Moorburg just tried to ignore the potential implications of the Port Development Law: “I do not care about the restrictions.” He added that “we as farmers in zone II are in a better position than others […] we are privileged, for us it’s still permitted to construct new farm buildings within our farmsteads.”Footnote 11 Moreover, he explained that the city constantly requires more land for sediment disposal and new infrastructure, such as the new A26 to Stade, and farmers still own significant amounts of land. He added that, together with other farmers, they recently achieved a major success against the Senate and the HPA. For their land on the planned route of the highway they received land in Moorburg, within the port expansion area, as compensation. He added that the authorities planned to compensate them with money but the farmers “only gave land for land,”Footnote 12 and the authorities finally agreed in order to be able to continue the road construction. Other forms of resistance mentioned by research participants were the construction of buildings without permits, explaining that in this part of Hamburg the administration does not have the capacity to monitor and enforce all regulations. Moreover, a resident argued that their construction activities are backed by the federal construction law which they claim is stronger than state law of Hamburg.Footnote 13 Another explained that he is seeking protection for some buildings from the historical preservation office to force Hamburg’s public housing company (SAGA), which owns most of the buildings in Moorburg, to maintain their buildings in order to complicate their demolition.Footnote 14

Currently, the clearing of Moorburg for port expansion does not seem to be very likely. However, the district and its classification as port expansion zone remain relevant for the disposal of dredged sediments. A staff member of HPAFootnote 15 confirmed that in the short term: “I cannot see the demand for a port expansion to Moorburg.” However, he also pointed to the fact that the construction of a new tunnel replacing the Köhlbrand Bridge will allow larger vessels to enter the CTA. He explained that the CTA could potentially be expanded towards Moorburg and that the possibility of constructing a port basin, which would affect the entire district, has not officially been abandoned. Environmental NGOs and all larger political parties, with the exception of the Social Democrats, are in favour of ending the designation of Moorburg and Francop as part of the port expansion zone.Footnote 16 Ironically, obstacles for a southward expansion of the CTA towards Moorburg are the large hills of dredged sediments and sediment-rinsing fields north of Moorburg. In January 2021, the chamber of commerce of Hamburg presented ideas for developing an “energy and climate port” in Moorburg. The plan foresees the retention of Moorburg, aligns well with the supposed role of ports in the blue economy, and focuses mainly on hydrogen shipping and production (Handelskammer Hamburg 2021).

Discussion

Despite centuries of attempts to tame the Elbe estuary, its complex tidal-influenced environment has not been stabilized and fully ‘standardized’, as the recent incident with the tanker Sten Arnold getting stuck in mud indicates. The territorialization of the Elbe estuary through dredging, reclamation, and the construction of dykes led to profound changes in the coastal morphology. The interventions created a clearer border between water and land and between shallow water and navigation channels. However, despite all efforts, the terraqueous territoriality of the Elbe estuary still remains highly volatile, dynamic, and difficult to control by established political and hydrological technologies of territory.

By literally following sediments from sites of extraction to terrestrial and marine dumping grounds, we argue that for understanding port- and estuary-specific forms of territoriality and also processes such as urban land reclamation — which is increasingly reshaping coastlines across continents —, it is worthwhile to consider the metabolic dimension of coastal transformation. The notion of the metabolism points to the permanent flows of aggregates within estuaries and deltas mobilized by the tidal regime and dredging vessels. If the metabolism were interrupted, the port and waterway function of an estuary would suddenly collapse and undermine trade and connectivity. Thus, to maintain connectivity, ports have to dredge and to permanently claim additional land for disposing sediments. Dredging and dumping of sediments is not a simple technical fix; it is a contested process, as protests in Moorburg and court proceedings initiated by fishers and NGOs indicate. Therefore, they reflect societal power relations in estuarine landscapes. They are the result of, and to some degree also explain, uneven development in estuarine landscapes, as they limit the development opportunities of other actors such as fishers, the tourism industry, farmers, and competing ports.

In the case of the Elbe estuary, the governance of estuarine landscapes within Hamburg and beyond, as the Federal Waterway Law and the Port Expansion Law indicate, secure the conditions of accumulation for the port industry by providing sufficient space on water and land for sediment disposal and future port expansions, and by maintaining water depths to allow the largest vessel classes to call at the port. Therefore, not only do disposal sites on water and land become sacrifice zones for maintaining connectivity to global trade but the whole estuary is transformed and impacted, and becomes a standardized environment (Carse and Lewis 2017). The historical development of Hamburg, and of port cities such as New Orleans and Antwerp, has been inextricably linked to their abilities to control the coastal landscape and to hold land reserves to expand port areas (Dooms et al. 2013; Lewis and Ernstson 2019). In Greece and Israel, for example, as in the case of Hamburg, port planning authorities have far-reaching competencies over land-use planning and laws restrict the construction of residential buildings in port areas (Teschner 2019). Over centuries, many port cities have successfully positioned themselves as central nodes in the regional economy and managed to subordinate their peripheries (Lewis and Ernstson 2019). Hamburg, for example, not only managed to maintain its connectivity by continuously expanding a navigation channel that crosses the territory of Schleswig–Holstein and Lower Saxony, the city-state also managed to benefit from uneven development caused by its dominance. The HPA and WSV, for example, developed biodiversity offsetting sites and environmental compensation measures beyond Hamburg’s state borders, where land prices and population densities are lower (WSV 2011, 2019). Dredged sediments are disposed of at buoy E3 in the coastal waters of Schleswig–Holstein, potentially impacting coastal fisheries, which — following the court decision on the fairway adaptation — count less than the port as a common good (Hein and Thomsen 2022).

Within its state borders, the Hamburg Senate has restricted the development of marshland agriculture and of residential areas in the southern marshes. Development in Moorburg has been “frozen” to spare land for the port and its sediments. “Value” created by toxic sediments in the rinsing fields of Moorburg seemed to outweigh the practices of the population and the marshland landscape created centuries ago in the course of colonization initiatives. In the periphery namely, residents in Moorburg, fruit tree growers, and fishers question the narrative of port growth as a common good for the entire region. So far, at least, Moorburg has successfully resisted being transformed into container terminals, but the apparent strategy of the Hamburg Senate to worsen the residents’ living conditions by, for example, surrounding the district with hills of dredged sediments and rinsing fields, has successfully reduced the population and the number of property owners to almost zero. However, Moorburg’s remaining inhabitants use their agency strategically and interpret regulations to their own benefit in order to maintain Moorburg as a habitable environment and to resist the production of Mooburg as a sacrifice zone for the sake of port developments. Moreover, the resistance of the population against the demolition of houses in the former village has very likely prevented the further expansion of sediment disposal sites and rinsing fields.

Conclusion

In this article, we showed how the materiality and the tidal-fuelled power of the estuary and constant hydrological interventions produce a specific form of territoriality, which is itself dynamic and in constant change, reflecting power dynamics within society and among humans and the estuary. Power asymmetries within society have led to uneven development in an estuarine region characterized by well-managed port zones, secured shipping channels and sacrifice zones for dumping sediments. However, a suddenly emerging below-water sediment hill challenging navigation, and resistance against the port expansion zone in Moorburg, illustrate power struggles involving the estuary as such, the population of Moorburg, the port authority and the waterway agency.

Our urban political ecology approach acknowledges that the territorialization of the Elbe estuary and the current shape of the estuary environment reflect historically rooted structured inequalities. This approach provides, from our perspective, a fruitful entry point to investigate the emergence of highly industrialized estuarine landscapes. It sensitives us to not take the current shape of the land–water interface and centre-periphery relations for granted. We suggest that, for investigating the “making” of coastal landscapes and port environments, it is imperative to rethink land-based notions of territory and to overcome the “agonistic relation between water and land” (Chalfin 2019: 815). From our perspective, thinking about an estuarine port as a specific form of territoriality linked through its metabolism to marine and terrestrial dumping grounds, is a fruitful avenue for developing a notion of territory that includes different aquatic spaces (from shallow to deep water, below-water disposal sites), spaces at the land–water interface (tidal flats, mangroves, salt marshes, urban waterfronts), and terrestrial and reclaimed zones, including sediment-rinsing fields and disposal sites. Moreover, we call for further research into metabolism and political ecologies of ports to improve our knowledge on the implications of ever growing ports for ecosystems and coastal populations. This is particularly relevant in the context of the increasing relevance of blue economy approaches, which mainly consider estuaries as operating environments for shipping industry and for new profit options such as sand mining. Critical port research in the marine social sciences could thereby help to counterbalance and challenge the often technical and modelling-driven approaches by planning authorities and hydrologists.