Adaptive Transformation of Historic Water Works in Hamburg, Germany: From Essential Infrastructure and Cornerstone of Public Health to Valuable Man-Made Ecosystems and Designed Public Spaces

Abstract

A lack of safe drinking water supply is the cause of a number of waterborne diseases such as cholera. Even nowadays, an estimated 100,000 people die from cholera each year. Since the early/mid-19th century relatively simple but highly effective engineering solutions were developed that helped provide clean drinking water. In 1892 the City of Hamburg, Germany was hit by a cholera epidemic and more than 8,000 people died within a few weeks. As a consequence, sedimentation and filtration systems to provide clean drinking water were built. They were in operation for nearly a century and subsequently became disused in recent decades. Since then, a number of proposals including large mixed-use developments were put forward and over time adapted to the changing needs to offer educational and recreational services, as well as enhancing natural assets. While the historic buildings of high heritage value were conserved, the sedimentation and filtration systems in their landscape setting transformed through natural succession combined with design interventions into attractive and valuable habitats. In addition, some of the former sedimentation basins were found to be the most suitable locations to compensate for the environmental impact of the highly disputed dredging of the Elbe River and were redesigned to provide a new habitat for a rare and endemic plant species.

● Just 150 years ago, there was essentially no infrastructure in place to provide a clean and safe water supply, which is regarded as standard today

● Unique projects for the adaptive transformation of historical technical infrastructure over a period of more than 150 years address new needs and uses through design interventions towards blue and green infrastructure

● As legally mandated compensation mitigating environmental impacts caused by dredging the Elbe River, the redesigned former sedimentation ponds function as a new habitat for endemic species

Graphical abstract

Keywords

Adaptive Transformation / Waterworks / Sand Filtration System / Cholera / Industrial Heritage / Recreation / Ecological Compensation / Ecosystem Restoration / Nature-based Solutions

1 Introduction: Evolution and Importance of Waterworks for the Provision of Drinking Water

Nowadays, in many countries around the world, people expect that perfectly safe, fresh drinking water is available by just turning the tap. On the other hand, even till now in many countries drinking water is a scarce resource. It is hard to believe that in the 19th century in industrialized countries such as Germany, or pretty much everywhere around the world there was no safe supply of drinking water. In Hamburg, one of the largest German cities at the time, people got their drinking water from the river Elbe, a major river originating at the Polish–Czech border and stretching over more than 1,000 km in length. As Hamburg is close to the sea, there is a considerable tidal influence^[1], with an average difference of 3.66 m between high tide and low tide, exerting a major effect on water quality depending on ebb and flow^[2]. At the same time, the river was used for drinking water and also as a natural sewer^[3]. Not surprisingly, the drinking water was potentially dangerous.

As a consequence, William Lindley, a famous English engineer who worked all across Europe was hired to improve the situation^[4]. Only from 1844 to 1848, an 11 km underground sewage system, as well as a waterworks a bit further upstream in the district of Rothenburgsort to supply the city of Hamburg with drinking water, was built^[4]~[7] (Fig.1). This was the first modern water and sewerage system in mainland Europe. Lindley also suggested a sand filtering system, but for economic reasons it was not implemented. Only four basins for basic sedimentation, without any filtering, were constructed nearby Billwerder^[4].

Although systems for the actual supply of drinking water have been used for thousands of years (e.g., in the Mesopotamian and Mediterranean Region), the actual engineered treatment of water started as late as 1804 when John Gibb designed a slow sand filter for his bleachery in Paisley, Scotland^{[8] [9]}. Other examples to treat sewage and wastewater include the trickle fields in Berlin, which were established in the late 19th century. The wastewater was dispersed over an area of around 100 km² and filtered by the sandy soil^[10].

In 1829, slow sand filtration was introduced on a large scale at the Chelsea Waterworks in London by the engineer James Simpson^[8]. Sand filtration mimics natural processes by removing contaminants (e.g., organic pollutants) through physical (e.g., adsorption) and biological processes helped by non-pathogenic aerobic microorganisms^[11].

2 Waterworks and Cholera: The Hamburg Cholera Epidemic of 1892

While the practice of sand filtration appeared to be very efficient in providing high quality drinking water, broader health science and knowledge about water sanitation was still in its infancy and the existence of pathogenic bacteria in water was unknown.

This was of particular importance as cholera was a widespread disease killing many thousands on a global scale. Quite similar to the early phase of the recent outbreak of the COVID-19 pandemic, at the time it was not clear how the cholera disease was spreading, for instance, water or air through poisonous vapors. In 1854, the physician John Snow investigated approximately 600 deaths in one week caused by cholera and discovered a causal connection between the type of water supply and the fatalities^[12]. In autumn 1892 in Hamburg, there was a major outbreak of cholera killing more than 8,000 people in 10 weeks^{[3] [13]}. Taking into account the larger population nowadays, the death toll then was about three times higher than during the recent COVID-19 pandemic. Robert Koch, a pioneer in bacteriology, investigated the epidemic in Hamburg in detail^[14]. He found that within the contiguous cities of Hamburg and Altona there were clear boundaries separating cholera-infected and non-infected areas^[15].

All infected areas had their water supplied from the city of Hamburg, which drew the drinking water upstream from the Elbe River at Rothenburgsort (Fig.2). The areas not infected were in the neighboring town of Altona which took its drinking water further downstream out of the Elbe River as well. The water quality in Altona was inferior, because the water of the Elbe was highly polluted by the sewage and faeces of about 800,000 people upstream^[3]. However, unlike in Rothenburgsort, Altona had a sand filtration system which helped eliminate the cholera bacteria from the drinking water. Thus Koch was able to prove that cholera bacteria were transmitted via the water and that water filtration was key in providing healthy drinking water^[8].

3 Waterworks in Rothenburgsort and Altona

3.1 Rothenburgsort Waterworks: The Filtration System on Kaltehofe Island and the Sedimentation Basins at Billwerder

Based on the proposals by Lindley, the city of Hamburg established the waterworks in the district of Rothenburgsort, upstream to the East of Hamburg, relying only on four simple sedimentation basins at Billwerder, completed by 1856 (Fig.1, Fig.3). Furthermore, Lindley suggested to construct a large sand filtration system on Kaltehofe Island, just nearby. For financial reasons, it was put on hold until 1890 to start with the construction of the filtration plant^[16]. Already by May 1893, but rather tragically, just after the cholera epidemic, 18 sand filtration basins were completed on Kaltehofe Island with another four by 1896 (Fig.4), constituting the largest plant for water purification of any city at that time^[17]. Initial cleaning was performed by the basins at Billwerder. This ensured provision of safe and clean drinking water from Rothenburgsort to Hamburg until 1990 when the filtration plant on Kaltehofe Island was shut down^[4]. Kaltehofe Island is a unique example of industrial heritage from the 19th century, as it is the only place worldwide where these sand filtration basins still exist and are now transformed and adapted to new functions.

3.2 Altona Waterworks: The Water Pumping System and Sedimentation Basins at Falkenstein

Already in 1859 Altona waterworks started their operation. The key feature was pumping the water directly from the Elbe River at Falkenstein up to the nearby Baursberg Hill, which at 91.6 m elevation is by far the highest point along the Elbe River, a distinctly visible moraine remnant of the glaciation several thousand years ago. The pumping typically happened during or just before high tide, when the best water quality in the Elbe River was reached, i.e. at that point the polluted water from Hamburg which lies upstream was pushed back by the tide^[4]. In addition, in 1896 two sedimentation basins along the banks of Elbe River at Falkenstein were constructed to ensure a pre-cleaning process before the water was pumped uphill (Fig.5). This system involving sedimentation and pumping the water uphill to Baursberg was in operation until 1960. Because of the increasing levels of pollution of the river, the waterworks switched to pumping groundwater.

4 Transition Towards Nature Protection, Recreation, and Industrial Heritage at Rothenburgsort/Kaltehofe

After the sedimentation basins on Kaltehofe Island were shut down in 1990 and fenced off, natural succession with pioneer vegetation took over, including shrubs and trees, wild perennials, and aquatic plants, forming an undisturbed habitat for birds (44 breeding species), bats, small mammals, and amphibians^[18].

An initial proposal was developed to turn the disused site into a mixed-use urban development for approximately 10,000 people living and working on the site, comprising apartment blocks with 4 ~ 6 stories, as well as 7-story office buildings and associated infrastructure such as hotels, restaurants, and 4,500 spaces for parking. This failed because it was too costly and there were high levels of contamination in the soil due to the nearby copper industry^[19]. At the same time local nature protection organizations wanted to conserve and protect the habitats. This conflict of opposing interests could not be solved and in order to coordinate the various stakeholders and their ideas, a local Agenda 21 process was initiated in 2004^[16]. This process builds on the 1992 Rio conference^[20] aiming to develop locally tailored plans for sustainable development by addressing local needs and concerns through the integration of local stakeholders in the decision-making process^[21].

Through meetings, workshops, and conferences, a range of proposals was jointly developed resulting in a masterplan for Kaltehofe Island, which featured a wide variety of possible recreational activities such as swimming, boating, and a 50-meter tall viewing tower as a key attraction^[22]. Again, this proposal was not financially viable.

Based on a downscaled masterplan, Wasserkunst Elbinsel Kaltehofe opened in 2011^[23], consisting of a 143,000 m² sized park in the central part of the island. The majority of the area is inaccessible or even designated as nature reserve and protected area according to the EU birds directive (Fig.6). The term "Wasserkunst" refers to water engineering, which had originated centuries ago in Germany; also, in the context of establishing water features such as fountains in parks of the nobility, the term linguistically relates at the same time to the terms "art," "artificial," and "skill."

The main features of the design include buildings of the former waterworks as industrial heritage, now used as a museum for educational purposes including a café and a venue for meetings. Other interpretative features and historical artifacts include information panels along the water basins, restored slider buildings controlling the waterflow, and a small train reminding visitors that the sand of the filtration basins had to be transported to a special sand washing facility^[23] (Fig.7).

Introduction of new uses include a barefoot trail, a nature discovery trail, wild flower meadows, bee hives, and a bird observation platform to provide opportunities for educational and recreational activities, and support ecological diversity of the site.

5 Transition Towards Nature Protection, Recreation, and Industrial Heritage at Falkenstein and Baursberg

Similar to Kaltehofe Island, there is an accessible as well as an inaccessible part of the site at Falkenstein and Baursberg. As the historic ensemble of the waterworks including the former pump house next to the Elbe River were not in use anymore, in 2015 they were sold to a private investor. To preserve the cultural heritage of the waterworks, the buildings were renovated by keeping the style and combining detailing from the 19th century with modern comfort. The buildings are now being used as private luxury homes as well as a rather unique event space for concerts and exhibitions. The sale of the property was granted subject to the grounds between the waterworks and the shore of Elbe River being accessible to the public^[6].

Since the time when the waterworks at Falkenstein and Baursberg switched to pumping groundwater instead of using the water from the Elbe River from the early 1960s onwards, the two sedimentation basins at Falkenstein became disused and over time turned into a valuable habitat for fish and amphibians^[24]. Right next to the Elbe River, the largest container vessels pass by on their way to and from the North Sea to the port of Hamburg, which ranks 18th globally in terms of tonnage^[25].

In 2010 an ecosystem restoration project in one of the basins took place^[5]. The eastern basin was opened to the Elbe River (Fig.8) and designed as an oxygen-rich shallow water site exposed to the tidal flow in order to serve as breeding and nursery area for a number of fish species including Twait Shad (Alosa fallax) and Asp (Aspius aspius)^[26].

The western basin remains as a key habitat for amphibians (Fig.9). Because of this, four special amphibian tunnels were built underneath the minor road separating the sedimentation basin and the nearby forest^[24].

Next to the basins a new park of 4,000 m² was built in 2011 and further extended in 2017^[27]. It is characterized by an orchard-type style with apple and pear trees, as well as by hedges and seating along the riverbank. Similar to Kaltehofe Island, interpretative panels inform people about the history of the waterworks making connections with features and relicts of the history of the site and the waterworks. Besides, the site on top of Baursberg Hill is still used as waterworks and is not accessible by the public. The buildings there are listed as cultural heritage.

6 Linking the Two Sites and Linking the Past and the Present Towards a Safe Future for an Endemic Rare Species

Because of the economic importance of the port of Hamburg, there was a strong interest not only in maintaining but also in widening and deepening the Elbe navigation channel^[1]. As a result of this highly disputed dredging project in the Elbe River fairway between Falkenstein and the island of Neßsand, now ships with a draught of 13.1 m (regardless of tide) or even up to 15.4 m (the largest current container ships) can pass each other on their way to Hamburg Port^[28].

This area is not only a special zone of conservation (a Natura 2000 site) of European dimension as a valuable fish habitat, but also home to an endangered and endemic plant species, the Elbe Water Dropwort (Oenanthe conioides)^[26]. It grows in freshwater tidal zones^[29] nearby the island of Neßsand and at a number of locations in the Elbe estuary, nowhere else on this planet. After 12 years of legal dispute the Federal Administrative Court of Germany in 2017^[30] ruled to permit the dredging of the river bed on the basis of establishing compensation measures to ensure survival of the plant. Following the mitigation hierarchy principle^[31], it was decided to offset the impact and to create a similar habitat at another location. Two of the four sedimentation basins on the island of Billwerder, originating from the waterworks project from 1844 and now also part of a nature reserve, were selected as the most suitable location to compensate the impact of dredging the Elbe River^[32].

As part of the project, an artificial habitat was created (Fig.10), resembling a maze of tidal creeks, mudflats, and small islands with shrubs and an alluvial forest along the river bank. Complicating matters even more, the site is at the same time the largest colony of cormorants in Hamburg^[33]. Because of their breeding season, the construction period had to be limited from September to February.

With a total budget of 11.1 million Euro more than 2,000 Elbe Water Dropwort were planted. As this plant is rather sensitive in terms of habitat needs, several nature protection organizations including WWF raised doubts whether the endangered plant will survive in the newly created habitat in the long term^[34].

7 Conclusions

Similar to other delta regions in the world, such as the Pearl River Delta^{[35] [36]}, the Elbe River is of key economic importance for the city of Hamburg, while at the same time it is home to valuable habitats for animals and plants, offering a range of ecosystem services. This leads to a number of potentially serious conflicts. Adapting the disused waterworks to new needs and uses, instead of destroying them, provides a multitude of opportunities and benefits. Industrial heritage can be experienced in its original setting and at the same time recreational activities as well as nature protection is supported. These unique projects are characterized by their inventive after-use and subtle interventions as valuable elements of the natural and cultural landscape.

Learning and benefitting from the principles of sand filtration and the positive effects on water purification^[37] only for decades, artificial wetlands (Fig.11, Fig.12), reedbeds or even wetland parks have been built and are nowadays established design interventions^[38][39]. While in the past such projects were solely approached from a water engineering perspective, they are now a well-established design feature in the project portfolio of landscape architects^[40][41].

Competing interests The authors declare that they have no competing interests.

References

[1] Hein, J., & Hilder, N. (2023). Estuarine territorialization and the port of Hamburg. Maritime Studies, (22), 39.

[2] Port of Hamburg. (2023). Tides in the River Elbe. Port of Hamburg.

[3] Exner, M. (2015). Cholera Epidemic in Hamburg, Germany 1892. In: J. Bartram, R. Baum, P. Coclanis, D. Gute, D. Kay, S. McFadyen, K. Pond, W. Robertson, & M. Rouse (Eds. ), Routledge Handbook of Water and Health (pp. 644–647). Routledge.

[4] Meng, A. (1993). History of Hamburg's Drinking Water Supply [Geschichte der Hamburger Wasserversorgung] (p. 454). Schubert.

[5] Sewig, C. (2010). New biotope on the Falkensteiner Ufer [Neues Biotop am Falkensteiner Ufer]. Hamburger Abendblatt.

[6] Ulrich, F. (2021). How a unique residential project was created on the Elbe [Wie an der Elbe ein einzigartiges Wohnprojekt entstand]. Hamburger Abendblatt.

[7] Hamburg Authority for the Environment, Climate, Energy and Agriculture. (2023). Falkensteiner Ufer Elbpark.

[8] Huisman, L., & Wood, W. E. (1974). Slow Sand Filtration (p. 122). World Health Organization.

[9] Ellis, K. V., & Wood, W. E. (1985). Slow sand filtration. Critical Reviews in Environmental Control, 15(4), 315– 354.

[10] Gray, M. W. (2014). Urban sewage and green meadows: Berlin's expansion to the south 1870–1920. Central European History, 47(2), 275– 306.

[11] Maiyo, J. K., Dasika, S., & Jafvert, C. T. (2023). Slow sand filters for the 21st century: A review. International Journal of Environmental Research and Public Health, 20(2), 1019.

[12] Tulchinsky, T. H. (2018). John Snow, Cholera, the Broad Street Pump; Waterborne Diseases Then and Now. Case Studies in Public Health (pp. 77–99). Elsevier Inc.

[13] Koch, R. (1893). Cholera in Germany during the winter of 1892 to 1893 [Die Cholera in Deutschland während des Winters 1892 bis 1893]. Deutsche Medizinische Wochenschrift, (26), 207– 261.

[14] Koch, R. (1894). Professor Koch on the Bacteriological Diagnosis of Cholera, Water-filtration and Cholera, and the Cholera in Germany during the Winter of 1892-93 (p. 150). David Douglas.

[15] Thorne, R. (1893). Cholera causation and prevention at home and at Hamburg. The Lancet, 142(3644), 50– 51.

[16] Schutzgemeinschaft Deutscher Wald. (2005). PAgenda 21-process Hamburg Kaltehofe [Agenda 21-Prozess Hamburg Kaltehofe].

[17] Shaw, A. (1894). Hamburg's new sanitary impulse. The Atlantic, (6), 787– 796.

[18] Brandt, I., & Haack, A. (2010). Wasserkunst Kaltehofe—Landscape management supporting plan [Wasserkunst Kaltehofe—Landschaftspflegerischer Begleitplan (LBP)] (p. 54). Hamburg Wasser.

[19] Schachtschneider-Baum, D. (2015). From Water Extraction to Local Recreation [Von der Wassergewinnung zur Naherholung]. In: D. Ermert, S. Horst, J. Lieven, & H. Stökl (Eds. ), In the River—Water in the Garden and Landscape [Im Fluss—Wasser in Garten und Landschaft] (pp. 14–17). Deutsche Gesellschaft für Gartenkunst und Landschaftskultur (DGGL).

[20] United Nations Conference on Environment and Development. (1992). Agenda 21.

[21] Smardon, R. C. (2008). A comparison of Local Agenda 21 implementation in North American, European and Indian cities. Management of Environmental Quality, 19(1), 118– 137.

[22] Schutzgemeinschaft Deutscher Wald. (2007). Masterplan Kaltehofe.

[23] Decker, E., & Schilling, J. (2017). Wasserkunst Elbinsel Kaltehofe. Hamburger Bauheft 15 (2nd ed. ) (p. 44). Schaff.

[24] City of Hamburg 2023. (2023, January 25). Safely to the spawning waters: Construction of amphibian protection system on Falkensteiner Ufer [Sicher zu den Laichgewässern. Bau von Amphibienschutzsystem am Falkensteiner Ufer].

[25] World Shipping Council. (2022). The Top 50 Container Ports.

[26] Elbe Estuary Working Group. (2012). Integrated management plan for the Elbe estuary.

[27] Krause, K. (2017). PFalkensteiner Ufer: New piece of beach for everyone—Elbpark opens in Blankenese [Falkensteiner Ufer: Neues Stück Strand für alle—Elbpark in Blankenese eröffnet]. Hamburger Abendblatt.

[28] Port of Hamburg. (2023). The fairway is ready for deeper ships.

[29] Kadereit, G., & Kadereit, J. W. (2005). Phylogenetic relationships, evolutionary origin, taxonomic status, and genetic structure of the endangered local Lower Elbe river (Germany) endemic Oenanthe conioides (Nolte ex Rchb. f. ) Lange (Apiaceae): ITS and AFLP evidence. Flora - Morphology, Distribution, Functional Ecology of Plants, 200(1), 15– 29.

[30] Hein, J., & Thomsen, J. (2022). Contested estuary ontologies: The conflict over the fairway adaptation of the Elbe River, Germany. Environment and Planning E: Nature and Space, 6(1), 153– 177.

[31] Arlidge, W. N. S., Bull, J. W., Addison, P. F. E., Burgass, M. J., Gianuca, D., Gorham, T. M., Jacob, C., Shumway, N., Sinclair, S. P., Watson, J. E. M., Wilcox, C., & Milner-Gulland, E. J. (2018). A global mitigation hierarchy for nature conservation. BioScience, 68(5), 336– 347.

[32] Bielfeldt, H. -R., & Berg, K. (2018). Coherence measure of "Tide connection Billwerder" Island [Kohärenzsicherungsmaßnahme „Tideanschluß Billwerder" Insel] (p. 114). Landschaftspflegerischer Begleitplan.

[33] Heyen, T., & Diekmann, L. (2020). Billwerder Island—Water fennel habitat in Moorfleet: Conversion is progressing [Billwerder Insel. Wasserfenchel Habitat im Moorfleet. Umbau kommt voran]. Bergedorfer Zeitung.

[34] Hamburger Abendblatt. (2021). Elbe deepening: Hemlock water fennel again causes annoyance [Elbvertiefung: Schierlings-Wasserfenchel sorgt erneut für Verärgerung].

[35] Nijhuis, S., Sun, Y., & Lange, E. (2023). Adaptive Urban Transformation: Urban Landscape Dynamics, Regional Design and Territorial Governance in the Pearl River Delta, China (p. 314). Springer Cham.

[36] Hehl-Lange, S., & Lange, E. (2019). The big picture: Landscape dynamics in the Pearl River Delta. Landscape Architecture, 26(9), 23– 30.

[37] Vymazal, J. (2010). Constructed wetlands for wastewater treatment: Five decades of experience. Environmental Science & Technology, 45(1), 61– 69.

[38] Huang, Y., Lange, E., & Ma, Y. (2022). Living with floods and reconnecting to the water—Landscape planning and design for delta plains. Journal of Environmental Engineering and Landscape Management, 30(1), 206– 219.

[39] Zhai, X., & Lange, E. (2021). The influence of Covid-19 on perceived health effects of wetland parks in China. Wetlands, (41), 101.

[40] Dreiseitl, H. (2020). Water and Sustainable Design. In: R. Meyers (Ed. ), Encyclopedia of Sustainability Science and Technology (pp. 1–19). Springer.

[41] Yu, K. (2021). Climate adaptation and resilience. Landscape Architecture Frontiers, 9(6), 4– 7.

RIGHTS & PERMISSIONS

Higher Education Press 2023