Uni Of Lodz
Nahuel Anschutz
The pilot river restoration activities implemented around the Sokołwka, using eco-hydrology as part of a Blue-Green Network, 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.
In response to this range of issues, a demonstration project of Sokołwka river restoration using natural processes was carried out in Lodz as part of the EU funded SWITCH project. A Blue-Green Network concept was piloted, aiming to improve urban ecosystem health, reduce flood risk, and ameliorate the microclimate, thereby contributing to better quality of life. The Blue-Green Network concept remains relevant in the city planning of Lodz and the multiple benefits of river restoration projects have sparked interest and action towards adaptation of the used technologies to new locations and development of green areas in connection to the water elements present in the city.
The Sokołwka River, which is mostly supplied by storm water outlets, runs partially in an artificial channel and has been prone to algal blooms due to high content of nutrients in the storm water. The objectives of the restoration project were as follows:
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. This step provided the information for the design and construction of 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. Moreover, the project led to a wider plan for rehabilitation of the Sokołwka river and a plan for the development of Sokołwka River park.
The changes in the Sokołwka valley raised interest among local developers. A 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 focusing 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 experiences and preliminary results of the Sokołwka river restoration project were also utilized in an EU LIFE+ project that took place in 2010-2015: ER-REK, Ecohydrologic rehabilitation of recreational reservoirs Arturwek (Łdź) as a model approach to rehabilitation of urban reservoirs. The rehabilitated Arturwek reservoirs provide an important recreational area for the city inhabitants that is visited by up to 3,000 people a day in high season. The sequential sedimentation-biofiltration system (SSBS) for stormwater purification developed in Sokołwka and EH-REK has been later utilized for the upgrade of efficiency in small sewage treatment plants.
The close links between the researchers from the University of Lodz and the City of Lodz, in existence since the 1990s, provided a solid basis for the collaboration in the SWITCH project. The cooperation was substantially enhanced and expanded 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:
The multiple benefits of the Sokołwka restoration project have not been quantified, but include at least avoided damages from urban flooding, increased value of the attractive urban environment, health benefits due to the improvements in air quality and the reduction of the urban heat island effect. The solution has proved itself in practice as the reservoirs collect excess water at every rainfall event and the area is evidently more attractive to live in. New buildings are planned to be built in the area and people are willing to pay more for the apartments in the area. Most importantly however, the people living in the area are very attached to the parks and the river which build up the local identity.
In May 2009, the recommendations for a Blue-Green Network were incorporated into one of the most important strategic documents of the city 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 officially became 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 the Water Framework Directive 2000/60/UE.
The re-engineering of the Sokołwka river took place primarily during the SWITCH project in 2006-2011. The rehabilitation project of Arturowek reservoirs (EH-REK) capitalized on the early results of the Sokołwka river restoration and was carried out in 2010-2015. The follow-up development projects initiated during the SWTICH project have been advanced later by the city of Lodz. The redevelopment plan of the Sokołwka park was approved in 2016 and a new concept for the wider rehabilitation plan of the Sokołwka river was developed in 2020.
Whilst restoration of damaged ecological systems and ecosystem functions is difficult and can be costly, it is also a long-lasting solution and its effects are likely to exceed the lifetime of one generation.
Maciej Zalewski
European Regional Centre For Ecohydrology Polish Academy of Sciences (ERCE PAS)
E-mail: m.zal...@erce.unesco.lodz.pl
UNESCO Chair on Ecohydrology and Applied Ecology, University of Lodz
E-mail: m.zal...@erce.unesco.lodz.pl