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Urban river restoration: a sustainable strategy for storm-water management in Lodz, Poland

Urban river restoration: a sustainable strategy for storm-water management in Lodz, Poland

The 19th century industrialisation in Lodz heavily affected the city’s rivers altering their ecosystems and hydrology. Many rivers in the densely built-up city were canalized. This resulted in a higher flood risk from runoff during heavy rain periods. Low water retention also implies reduction of soil moisture during dry spells, contributing to higher temperature and reduced air humidity (urban heat island).

As the projections suggest that the intensity of heavy rain periods and higher temperatures are likely to increase, these problems are likely to be exacerbated by climate change. In response, Lodz carried out several activities within the EU SWITCH project, as: 1) demonstration project of river restoration using natural processes, and 2) development of a new concept for the city planning, i.e. Blue-Green Network Concept. The developed strategy aims to: improve urban ecosystem health, reduce flood risk, and ameliorate the microclimate, thereby contributing to better quality of life.

Case Study Description


Lodz, whose name in Polish means 'boat', is located in the source area of eighteen streams. The proximity to water enabled the city to become a major manufacturing centre in the 19th century. Lodz’s industrial past and urbanisation resulted in serious water management challenges for the city. The majority of the city’s urban streams were canalized and transformed in culvert pipes. This, combined with high proportion of impermeable surfaces in the city and a consequent reduced rainwater absorption capacity of the land, contributed to an increase in surface run-off and in the speed of water outflow. As a result, parts of the city are badly affected by flooding during storms, which projections suggest may increase in intensity under the changing climate. Large parts of the city have combined sewers, which means that during heavy rainfall the capacity of the wastewater treatment plant is exceeded, which in turn results in pollution of a receiving river. Degradation of the freshwater habitats resulting from pollution and the artificial character of rivers reduces their capacity for water retention and self-purification, leading in turn to poorer water and ecological quality. In addition, the lack of green spaces and open waterways in the city increases air pollution levels, reduces humidity and causes a considerable urban heat island effect. Together these affect the health and quality of life of Lodz’s inhabitants. As the temperature is expected to rise in the future, the need for cool and green environments capable of dealing with heavy rainfall will also increase.


Two major activities were undertaken in Lodz:

  • Elaboration and demonstration of the strategy and technology for restoration of municipal rivers based on natural processes, aiming at: improved storm-water management, increased water retention, and better water quality supporting higher biodiversity and improvement of quality of life.
  • Development of the system-wide approach to the city adaptation strategy based on the  Blue-Green Network Concept. This  assumes that river valleys and green spaces are connected in the city planning and development process, to create a framework for a friendly city, which retains water, supports green infrastructure, encourages society healthy lifestyles, attracts business, and become resilient to global climate change.

Adopted solutions include a demonstration project, implemented on the Sokołówka River, and the development of an overall approach to urban planning based on the Blue-Green Network concept. The SWITCH project introduced a multi-stakeholder (i.e. Learning Alliance) involving all the actors in the city having interest in the water and natural resources management as well as regional and national stakeholders. The multi-stakeholder approach with strong research elements resulted in application of the principles of ecohydrology (studying the interactions between water and ecosystems) and Integrated Urban Water Management in the demonstration project “restoration of the Sokołówka River”. The Sokołówka River which is mostly supplied by storm water outlets, runs partially in an artificial channel and is prone to algal blooms due to high content of nutrients in the storm water. The objectives of this restoration project were as follows:

  • Apply innovative ecosystem biotechnologies according to the principles of eco-hydrology;
  • Increase the capacity of the river system to absorb the urbanisation impact (to increase water storage and purification capacity);
  • Restore the river functions to provide ecosystem services to the inhabitants.

The first step of the pilot project was the acquisition of accurate baseline data (e.g. chemical analysis of bottom sediments and water, biological and ecological data, river water budget and models for storm-water management) that were used to select the appropriate measures to be implemented. The results were used to design and construct three storm-water reservoirs (completed in 2006, 2009 and 2010) and a sequential sedimentation bio-filtration system for storm-water purification (completed in 2011) which was patented as a SWITCH innovation. The project led to a wider plan for rehabilitation of the Sokołówka river (the concept and technical project are finalised) and a plan for the development of Sokołówka River park (approved by the City Council and awaiting funding). The Sokołówka  River restoration project has contributed to resolving the following climate change related challenges:

  • Reduction of the storm-water sewage flow peaks by series of ponds and reservoirs, creation and restoration of river valley and wetlands;
  • Increase of water retentiveness in the city landscape (mitigation of extreme flows, increase of groundwater level, support of city vegetation) by application of phytotechnology;
  • Increase of the water quality, ecological stability of freshwater resources and their carrying capacity by instream ecohydrological regulation;
  • Increase of quality of life and aesthetic values in the catchment by restoration of the river corridor, ecotone zones and landscape;
  • Increase of human health by incorporating the measures into development plan of the city, based on relationships between the effect of green-lands and water on frequency of allergies and asthma cases.

The changes in the Sokołówka valley raised interest among local developers. One company, investing in a housing area near the river, was interested in contributing to more sustainable storm-water management, and decided to introduce related solutions such as retention wells, in a way that all storm-water can be stored entirely within their investment area. Several bottom-up initiatives focussed on rivers and green spaces emerged in other areas of the city, e.g., the historical area of Księży Młyn and Jasień river. Several NGOs became interested in green and blue infrastructure and the possible use of its services, e.g., alternative sustainable transportation routes (cycle paths) or green backyards.

The pilot river restoration activities implemented around the Sokołówka River have been a success, and have convinced the Lodz authorities and water professionals of the value of replicating these for other rivers across the city. One of the follow-up projects is Arturówek Reservoirs, which provides an important recreational area for the city inhabitants, visited by up to 3,000 people a day in high season. This area is now a subject of the EU LIFE+ project “Ecohydrologic rehabilitation of recreational reservoirs Arturówek (Łódź) as a model approach to rehabilitation of urban reservoirs”.

Following on from the Sokołówka river demonstration project, the Blue-Green Network concept was developed by the researchers from the European Regional Centre for Ecohydrology at the Polish Academy of Science in Lodz in 2008. The idea is to frame the development in the city by a network of (restored) river systems and green spaces (agricultural areas, parks and brownfield land). Connecting ‘blue’ and ‘green’ spaces could help to maintain the continuity of ecological processes and provide an integrated approach to storm-water retention and to purification and amelioration of the city microclimate, thus allowing flexible adaptation to climate change and improvements in quality of life and environment in the urban area.


Case mainly developed and implemented because of other policy objectives, but with significant consideration of CCA aspects

Additional Details

Stakeholder Participation

The close links between the researchers from the University of Lodz and the City of Lodz, in existence since the 1990s, provided a good basis for the collaboration in the SWITCH project. The cooperation was substantially enhanced and widened to include other relevant stakeholders through the establishment of the SWITCH Learning Alliance in Lodz - a stakeholder forum for exchanging ideas, plans and interests, with allocated EU funds for its activities. This process started in March 2006, initially involving the stakeholders perceived to have the most critical roles in water management. Over time, additional important actors were identified and involved. The key stakeholders in the Lodz Learning Alliance at its peak included partners from 25 different organisations, the most important being:

  • City of Lodz departments: Municipal Management, Environment and Agriculture, Strategic Planning;
  • Waterworks and Sewage Company, which operates the treatment plants and water supply and sewerage networks in Lodz;
  • Lodz Infrastructure Company, which owns the treatment plants and water supply and sewerage networks in Lodz;
  • Lodz Wastewater Treatment Plant;
  • Research institutes: (i) Department of Applied Ecology of the University of Lodz, (ii) European Regional Centre for Ecohydrology under the auspices of UNESCO – the International Institute of the Polish Academy of Sciences, (iii) Technical University of Lodz, (iv) Medical University of Lodz, (v) Institute of Occupational Medicine in Lodz;
  • Several NGOs, which joined the Lodz Learning Alliance in 2009 at the Blue-Green Network development launch.

The learning Alliance built and trained a facilitation team, developed a website and communication strategy and hosted several meetings, trainings and workshops on different urban water management issues. Each workshop expanded the membership of the Alliance. The SWITCH team in Lodz undertook a wide range of awareness raising and advocacy activities. These included engaging young people to raise their awareness of environmental issues and to create interest in the city’s hidden rivers. The mass media, especially radio and newspapers, were also engaged. 

Success and Limiting Factors

Main success factors can be summarised as follows:

  • Participation in the SWITCH project was a major driving factor, not least due to the funding available through the project. Participation in the project helped to marry the technical expertise with the planning in the city and raise awareness of the need to consider green and blue spaces in the city. A professor from the University of Lodz stated that “SWITCH has completely changed how the city looks at water (...) The idea that water and green areas can be central in the future of Lodz has become an accepted view in the city”.
  • Stakeholder involvement through the Learning Alliance was a strong driver of the initiative. Through the alliance, strong new linkages were forged between scientists, decision makers and other key stakeholders. These links are being maintained well beyond the conclusion of the SWITCH project.
  • A big part of the Learning Alliance success is due to the strong champions within the forum. Committed individuals, in particular a professor from the University of Lodz who has promoted river restoration since the 1990s, have been instrumental to the process of building the partnership and keeping it going. The success of the Learning Alliance also relied upon strong facilitation, frequent communication, and the commitment of stakeholders from all organisations to regular involvement. Although the Learning Alliance is no longer operating officially, the links established still bring benefits, in the form of new projects, initiatives and better cooperation among the Learning Alliance former members.

Discontinuation of funding after completion of the SWITCH project is a major limiting factor, which means replicating  the demonstration project will be difficult.

Costs and Benefits

The EU funding was vital to the project. The total SWITCH project budget for activities in Lodz of about €1,150,000 covered the costs to the university and to the City of Lodz for five years. The Sokołówka River demonstration project had a budget of approximately € 700,000. About € 130,000 was invested in the Learning Alliance activities. It should be mentioned that many in-kind contributions were made, in particular by the researchers and PhD students from the research institutions in Lodz.

Benefits have not been quantified so far, but need to be computed taking into account avoided damages from flooding in the urban area, increased quality of the urban environment, improvements of air quality and reduction of the urban heat island effect.

In May 2009, the recommendations for a Blue-Green Network were incorporated into one of the most important strategic city’s documents used as a basis for spatial planning: the Study of Conditions and Directions of Spatial Development of the City of Lodz. In 2012, the concept became officially part of the Strategy for Integrated Development of Lodz 2020+. The follow up Arturowek Reservoirs project directly responds to the requirements of the EU Directive 2006/7/WE on bathing waters and Water Framework Directive 2000/60/UE.

Implementation Time


Life Time

Whilst restoration of damaged ecological systems and ecosystem functions is difficult and can be costly, it is also long-lasting and its effects are likely to exceed the lifetime of one generation.

Reference Information


Dr. Iwona Wagner
University of Łódź
Department of Applied Ecology University of Lodz
90-237 Lodz, 12/16 Banach Str.
Tel. +48 42 635 44 48
E-mail: iwwag@biol.uni.lodz.pl

SWITCH (Sustainable Water Management Improves Tomorrow Cities Health) project

Published in Climate ADAPT Jun 07 2016   -   Last Modified in Climate ADAPT Dec 23 2020

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