Improved water quality

The Brackwede open-air pools have been a significant landmark of the city of Bielefeld and part of locals' life since 1926. After several renovations since its opening, in 2005, the maintaining company of the Brackwede open-air pools proposed to convert the pools into natural-water bodies through the application of natural water filtration systems. The pools are supplied from the natural underground stream of Ems-Lutter whose spring water is physically and biologically purified by natural mineral soil filter and water plants. Chlorine is prohibited in this pool - the nature itself ensures water quality (1). Since 2009, the Natural pool of Brackwede offers natural facilities for swimming and other water-related activities besides cultural, sport and recreational opportunities for all (1).

On the derelict industrial plant in Brackwede, which was independent until 1973, a large leisure facility with an extensive range of leisure activities was planned. However, due to more recent findings, this direction was rejected and a natural green corridor was created with unique biotope areas that had developed over time from the abandoned bleaching ponds and meadows. The Luttertal is located in Bielefeld Quelle, south of the
The industrial plant in Brackwede was intentionally abandoned since 1973, due to the local municipality recently cancelled the project of the redevelopment of the area and kept it intact. Till now, a “natural green area developed with very interesting biotope areas, which had evolved over time” at the abandoned site.

The lagoon has a great local significance for its biodiversity with the presence of certain species of rare birds regularly stationed in this area. Much of the biotope was degraded in the last decade by systematic embankments, constructions, as well as the inconvenience caused by various man-made pressures. A project was developed to reconstruct the area within the framework of a collaboration of the Institute of Marine Biological Resources, Inland Waters of HCMR, and Hellenic Ornology Company. The project offers directions for completing a protected region and proposes specific projects and actions of scientific monitoring, ecological rehabilitation, regeneration, and promotion. (Ref 3)

A significant expansion of the summer water level in the biggest local natural river, Giber River, was carried out in Aarhus. The increase in water flow in Giber River was achieved by a range of different measures, such as pumping purified wastewater into the river and building a string of rainwater collection ponds that will be allowed to slowly drain into the river. (Ref. 1)

“An integrated solution for groundwater, rainwater, waste water, streams and ponds creates attractive housing in a new suburb (NyE), with room for exciting architecture. The water cycle plays a key role in urban development in Denmark, and water is one of the ever-present elements in our lives. Århus needs to prevent flooding caused by climate change, avoid polluting our groundwater, and improve the environment in streams and ponds to allow the use of water to create recreational value for the residents. This way, Århus can build a balanced aquatic environment, which will ultimately create a better city.” (Ref. 1)

The establishment of the first stage consisting of 650 homes, day care center and grocery store was initiated in the autumn of 2016 after more than 10 years of planning, and in the summer of 2018, the first residents moved into Nye. More homes are on the way. (Ref 14). In its current form of just over 150 ha, it has a capacity of approx. 15,000-20,000 inhabitants or approx. 10,000 homes at full expansion (Ref 15)

The project was about restoration of the Aarhus river. The river was piped during the 1930s for hygienic reasons and to give space for road infrastructure. In 1989, the city decided to resurface the river. The river acts as a green and blue corridor running through the city centre. Furthermore, The City Council approved a plan for the recreational vision of the Aarhus River and e.g. flood prevention measures have been taken. (Ref. 1, 2, 3) The Aarhus Å project was completed in the years from 2006 to 2013. (Ref. 15)

Before the intervention, the dam was a derelict former industrial and recreational area. (Reference 6) It was transformed into a green recreational park of the southern part of Budapest. 40,000 square metres of grass was laid, 700 trees, 20,000 shrubs and 20,000 perennials were planted. (Reference 4) The park now is a home to a biodiverse population of wild birds. It is one of the few places of the city that have direct connection to the Danube, giving space for strolling, doing sport, playing and relaxing. In 2018, a large-scale development began next to the dam, with the aim of creating a new city center. This would make the park a place for leisure for much greater number of people, but may be detrimental to the ecosystem of the dam. (Reference 6)

The Street Office (Gatukontoret) and VA Syd rebuilt Fjärilsparken (The butterfly park) in Bunkeflostrand (Malmö). For the shallow stream that runs through the park the slopes of the dikes have been made flat, meadow vegetation and wetland-plants planted in the wetlands. An area east of the park was built with houses and stormwater was managed in new ways (ref. 1). Opening the park up to the sea, flower beds were planted for richer plant and wildlife, butterfly-attracting plants were planted, lighting for safety was installed and areas with benches and bridges were created (ref. 1).

The 18 km long Rheindorfer stream flowing into the Rhine has faced increased urbanization, industrial activity and surface sealing over the last decades of the 20th century. As a result, numerous interventions were made to its original structure, such as the creation of a concrete bed for the stream and the straightening of the stream course. Meanwhile, an increasing amount of pressure was put on its water carrying capacity. In order to improve the flood retention capacity of the stream, the renaturalization project of the stream was executed in some parts of the water body. The project aims were 1) to restore the natural course of the stream and the state of the riverbeds, thus enhancing the stream's capacity to buffer floods, 2) restore the natural biodiversity of the floodplain and 3) to create a recreational area for locals (1,2).

This NBS involved the reconstruction of two of the total of four lakes/ponds at the Iron Fountain (Železná studnička) and was one of the project sites undertaken by the Bratislava Zelenaj project. (7, 8, 10) The location served as a recreational and relaxing spot for locals and tourists. To undertake the reconstruction, the two lakes/ponds no. 3 and no. 4 had to be discharged. Upon doing so many species of fish were found, including carp, caras, catfish, rabbitfish, toothpick, lure or amur, and also bivalve molluscs and troughs. Reconstruction of water reservoirs (ponds) no. 3 and no. 4 were implemented by the City of Bratislava within the framework of the project in cooperation with the Monumental Office of the Slovak Republic and the Municipal Forests company. (9, 11, 20)