Improved water quality

The Green Corridor Bernetal developing on the site of the former sewerage system will link the downtown of Essen with the districts of Altenessen and Freiräumen in the North of the city. New green and blue infrastructure will be introduced along the modernized way available also for pedestrians and cyclists. The project is developed along with the city policy towards environmental regeneration of the Emscher region (Ref. 1).

The Molenvlietpark is a large park in the Viletzoom area of The Hague which will serve as an ecological corridor and stormwater storage. Beside flowery grasslands, the park has several interconnected ponds serving as water storing facilities that can temporarily collect a large amount of water during heavy rainfall. The green and blue areas with diverse vegetation provide habitat for a large variety of species and a fish spawning ground supporting biodiversity (1,5,6,7). It will also include paths for cyclists and pedestrians. (1) The first phase of the park construction has been completed, while the second phase is planned to be executed in 2021-2022.

Paljassaare peninsula hosts the Paljassaare special conservation area and is partly a nature reserve and partly used to accommodate a wastewater treatment facility (ref 3). The leftovers from the treatment facility, processes of urbanisation and cyanobacteria blooms from the Baltic sea are largely influencing the fragile ecosystem of the peninsula through eutrophication. By this, the different cycles and ecosystems (both natural and urban) got more and more intertwined. ‘Perpetuum Mobile’ project aims to rebalance the urban metabolism of Tallinn city with the ecological processes on the Paljassaare peninsula through natural de-eutrophication of the area (ref 4).

In 2017, under a bigger project, the municipality of Sintra started the work for the rehabilitation of an area that included beaches and rivers, such as the Mata river. The NBS solves a problem of accumulation of water and sludge that was unsolved, through the recovery and cleaning of Ribeira da Mata (small river/brook), planting trees and promotion of an improvement in water quality and sand on the beach.
(1)

The main problem of Lake Ülemiste is high phytoplankton biomass, which increases the cost of water treatment (ref 1). Improving the water quality of Lake Ülemiste by biomanipulation has been considered as a management alternative. Lake Ülemiste was bio-remediated after reduction of external loading and the shifts in water quality were studied during the active-phase of the measure. (ref 1). Tallinn obtains 88% of the water it needs from Lake Ülemiste. Pine forest in the sanitary protection zone surrounding Lake Ülemiste offers several ecosystem services that help to improve the quality of the city’s drinking water (ref 4).

This project aimed at the reconstruction of the Lepiku channel that is part of the drainage system, which starts next to the Tallinn Botanic Garden and includes wetlands, detention ponds, ditches and channels and flows into the Pirita river. The aim of the project was to improve the quality of the stormwater that flows into the Pirita river which is a Natura 2000 site and flows into the Baltic Sea. The work included: widening of channel bottom in different segments, creating artificial dykes and rapids and creating suitable conditions for the aquatic plants exhibited in Botanic Garden (ref 1). With the project, 200m of the channel was reconstructed (ref. 5).

The "Ciobarciu wetland" project resulted in the creation of a wetland area of ​​about 224 hectares near the city of Iasi (30 Km distance). The area of ​​nature thus became in spring and autumn a significant resting place for migratory birds, and the specific types of natural vegetation are growing again, constituting a natural habitat for the locales specific to these places. The project was developed by the National Administration of the Romanian Waters alongside the Dutch Government in order to restore the area and to include it in the ecosystem of the place (1)

The Deûle park is a periurban park in northern France, which was created to protect the irreplaceable capture fields of the south of the Lille conurbation. It is an important element of the Regional Green Trail and an important recreation area in a region that is particularly densely urbanized and poor in green spaces. The park is the winner of the " Landscape Award 2006" and the European Landscape Award from the Council of Europe in 2009 (Ref 2).

The water treatment station in Marquette-lez-Lille had a makeover in September 2014. The facility was renovated and rebuilt with cutting-edge technologies and included a new energy production unit. The plant serves 37 municipalities with treated water. The renovation project enabled the station to be integrated into an urban environment. Almost 17 acres have been transformed into a wetland with the planting of more than 20,000 trees and shrubbery. Encircled by a high-speed road, the Deûle canal, a forest and homes, this classified site is marked by exceptional biodiversity. The Marquette station is recognized as a leader in its industry and was nominated by Global Water Intelligence (GWI) as one of the four projects of the year worldwide for 2014 (Ref 1).

Since the decay of the former DDR, the lignite industry had a major downturn. Most of the mines were closed and its remaining craters re-naturalized and flooded with ground- or rainwater to be revived as recreational lakes. In the Leipzig area of "Neuseenland" up to 23 artificial lakes were created since the nineties by the respective mining company "Lausitzer und Mitteldeutsche Bergbau-Verwaltungsgesellschaft mbH" which has the obligation to securely and sustainably redevelop the area into forestry, agricultural, natural or recreational areas and reintegrate it into the adjacent landscape. The lakes have become important recreational areas for citizens (4, 8).