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Department of Spatial Planning
Urban River Regeneration

Urban River Regeneration - Evidence from international comparative research on old-industrial regions

In this study a combination of a survey and case studies serves to answer the central question of what approaches to river restoration exist in old-industrial regions.

In the Ruhr region in western Germany, the "Emscher reconstruction" of the past thirty years has enormously improved the water quality and ecological condition of the Emscher river system and created a green-blue infrastructure in the Ruhr region that is attractive in terms of landscape. In the coming years, it will be important to capitalize on these successes and use them as a driver for regional development. New impulses are needed to achieve a substantial improvement in the quality of life in the Emscher region that goes beyond the ecological and landscape improvements that have been made. In doing so, the Ruhr region can learn from experiences made else­where. To this end, the project will create a database in which old-industrial city-regions worldwide with their selected watercourses (rivers and canals) have been recorded. Secondly, particularly inspiring examples of urban regeneration through river restoration in old-industrial city-regions will be compiled in the form of information sheets. The combination of survey and case studies serves to answer the central question of what approaches to river restoration exist in old-industrial regions.

Old-industrial areas today often face multiple challenges. On the one hand, they suffer from the loss of function of once dominant industries and a process of deindustria­lization with typical consequential problems such as job losses, low per capita income, social problems and migration. On the other hand, since industrialization, nature in these areas has experienced an unprecedented degree of transformation and environmental destruction. An essential prerequisite for industrialization was the location of produc­tion sites on navigable rivers or the coast, as well as a favorable water supply. Rivers were used not only for the transport of goods, but also for industrial production, energy generation, potable water production and wastewater disposal. In the emerging industrial age, many canals were also built as waterways fed by river water. To this day, many soils and waters at old-industrial sites are contaminated with highly toxic pollutants.

Thus, the "Urban-River Regeneration" approach combines trends and socio-economic challenges of urban regeneration with legacy and ecological challen­ges of river restoration in old-industrial city-regions.

To describe the examples, the dimensions of context (polity), process (politics) and content (policy) are considered. Strategy research and political science today recognize that political or strategic decision-making processes can only be analyzed and explained with a view to all three dimensions and their interactions. Just as content and process are inextricably linked, all strategy processes are embedded in specific contexts and can only be interpreted in relation to context. Variations in context or process, as well as shifts over time, lead to changed outcomes. A deeper understanding of the cases under consideration is therefore only possible if all three or - if the temporal dimension is added - four dimensions are taken into account.


For the database, a comprehensive desk research is conducted as part of the present study. This covers old-industrial city-regions worldwide in which river restoration projects were implemented to upgrade urban spaces. The basis is primarily a systematic internet search. The main sources of information for this secondary research includes websites of authorities, communities, associations and research institutions, but also academic literature and press articles.

Three criteria are used in the creation of the database:

  • 1st criterion: Old-industrial region of the first two industrialization waves
  • 2nd criterion: Urban environment with at least 50,000 inhabitants in the urban region.
  • 3rd criterion: Running waters with moderate to poor ecological status.

For all cases, the following attributes are recorded:

  • World region
  • City-Region
  • Country (in the US and Canada also states and provinces)
  • Population in city-region
  • (Selected) flowing waters, differentiated according to heavily modified and artificial waters.

To date, the database includes a total of 511 old-industrial city-regions worldwide, 264 of which are in fourteen countries in Europe, 237 in twenty-seven states in the USA and two provinces in Canada, and 10 in Japan. Approximately 386 million people currently live in these old-industrial city-regions.

A total of 1,641 urban watercourses (rivers, streams, and canals) were surveyed in the so far included 511 city-regions. Some of the water­courses flow through several old-industrial city-regions in their course. This is especially true for major rivers (such as the Delaware, Elbe, Hudson, Mississippi, Ohio, Po, Susquehanna, or Thames), but also significant canals (such as the Erie Canal, Grand Union Canal, Leeds and Liverpool Canal, or Ohio and Erie Canal). Subtracting multiple responses, the total number of waterbodies included is so far 1,349 urban watercourses. Of these, 192 canals are classified as artificial waters.

In Europe, 86% or 228 of the 264 old-industrial city-regions are concentrated in seven countries: the UK (82), Italy (48), Germany (38), France (18), Poland (17), Czech Republic (14) and Belgium (11). Similarly, in the U.S., clusters also emerge in eight 'Rust Belt' states in the Midwest and Northeast: the most old-industry city-regions are in Ohio (30), Pennsylvania (29), Wisconsin (24), Michigan (22), New York (22), Indiana (19), Illinois (17), and West Virginia (14). In Canada, the geographic focus is Ontario (22).

In terms of population, Tokyo, New York City, Kansai (with Osaka), Paris, London, Chicago, Aichi (with Nagoya), Washington, Phila­delphia and Toronto are among the top ten largest city regions with an old-industrial heritage. The Ruhr region and Berlin follow directly behind in eleventh and twelfth place. Relatively few large city regions are contrasted by a relatively large number of medium-sized and smaller city regions. The arithmetic mean of the number of inhabi­tants is around 750,000, the median around 200,000. 95 of the 511 city regions have a population of 50,000 to 100,000, which is only just above the minimum value (criterion 2). However, 72 city regions have more than 1 million inhabitants. With 272 million people, they are home to more than two-thirds of the inhabitants of the 511 old-industrial city regions.

In Europe, old-industrial city-regions with particularly high numbers of heavily modified or artificial waters include cities such as Berlin, Birmingham, London, Milan, Manchester, Padua and Turin. In America, this is true of cities such as Baltimore, Boston, Chicago, Cleveland, Milwaukee, Montreal, New York City, Philadelphia, and Toronto.

Good Practice

Best practice is a common business method for empirically determining the best solution for a task by bench marking. Best practice studies should help to solve tasks in an optimal way by using experiences from comparable situations. However, it is questionable to what extent there can be a standardized optimum for complex urban and spatial development tasks, a best way that can be measured in terms of key figures. Therefore, good practice studies do not focus on the best solution, but on practically successful solutions that are potentially exemplary and worthy of imitation according to. They represent an aid on the way to a solution, but do not intend to be a blueprint. By evaluating projects that have already been tried and tested and thus concentrating on the past, the innovative content of good practice studies is naturally limited. However, there is creative potential in the (partial) transfer of solutions to a new context.

Very different solutions can be considered good practice at the same time; the possibilities for comparison are thus broader and more open from the outset. However, this does not exempt an evaluation of the examples considered in terms of observable results and sustainable (and potentially replicable elsewhere) success of the measure.

In the present project, examples that are particularly worthy of imitation are selected from a good dozen of the old-industrial city-regions recorded in the database. In the sense explained above, the focus is not on the best, but on good examples of neighbor­hood revitalization and conversion through blue infrastructure measures in urban areas. In addition to the information already collected in the desk research, supplemen­tary primary surveys were conducted on the selected projects, in particular through walk-throughs and interviews. The infor­mation collected in this way was processed and evaluated using a standardized system and condensed into a case description in the form of a two-page information sheet.

In addition to a brief description of 400 words of the case study, all info sheets contain information about the city-region, the flowing waters, the duration and the type of urban-river regeneration. In addition, the info sheets contain illustrations, a map, and selected additional sources on the case study.



Prof. Dr. Thorsten Wiechmann

Dr. Letizia Imbres

Duration: 01.10.2022 - 30.09.2024