Improved water quality

The renaturalization of the water canal Hirtenbach project was part of the larger city-wide initiative that aimed at the naturalization of different parts of the city's drainage system including small trenches and streams. The initiative aimed to decrease the risk of floods, improve the water quality, protect the local flora and fauna from the pollution, as well as provide for an additional recreational area for the citizens. (Reference 1)
In 2000, natural remodelling or the creation of near-natural structures began in sections. A 20, 000 m3 retention basin was also built. These actions improved flood protection and ecology of the area, and it provided local recreation opportunities. However, a study conducted in 2014 revealed that the restoration measures brought positive changes, but it was not enough to achieve a “good water status” defined by the European Water Framework Directive. Intensive care from silting and lush plant growth, wide margins, and the reduction of nutrients coming from the drainage and agriculture, need to be addressed. (Reference 2)
A new landscape is expected to be created when the alder trees grow. Waterbirds and waders, as well as insects like dragonflies, bees, butterflies and crickets, have been observed in the area (Reference 3).
The large drainage system of the city of Hannover includes many small trenches and streams with a total length of 152 kilometres. The intervention in Hirtenbach involved renaturalization worked on the total length of approximately 10,5 km (of which 3,3 km in the urban area). (Reference 2)

In 2016, owing to the participatory budget of Białystok, the citizens received a long-awaited outdoor gym and playground in the vacant green area of the city. The initiative aimed to increase public access to the green recreational area in the city, and connect the Białka riverside with residential boroughs. The project involved greenery planting and re-arrangement of the greenery (including some deforestation), revitalization of a pond and water purification, connecting walking and bicycle paths. Lawns are available for family picnics and recreation [1,2].

Owing to European Funds, the University of Białystok opened a new modern ecological campus for the faculties of biology, mathematics and computer science. The new campus was designed to incorporate green and blue infrastructure elements, and embody the pro-ecological profile of the investment. Green vegetation covers the university's walls and roofs, which is nearly half of the 30,000 square meters big campus. There is a brook around buildings and small ponds in the university's inner courtyards. The campus uses a sustainable rain drainage system, which is located on the roof, and the rainwater flows to the artificial water tanks and is continuously filtered and redistributed. Finally, there is a publicly accessible centre for ecological education. Large decorative installations on each of the four courtyards enhance the aesthetic experience in the campus and inspire the faculty and students [1,2].

The project revitalized two old ponds – previous industrial and derelict area – and created two new ponds on the Marczukowska street in the city of Bialystok. The investment in its current shape is a tourist attraction and a valuable ecosystem for birds and amphibians. The project resulted in the increase of biodiversity in the area (additional ponds for the breeding of amphibians, two nesting islands not accessible to the public), and more effective management of the local water resources (cleaning and deepening of ponds, restoring an outflow for the excess water directly to the Biała river). Finally, it is a popular place with publicly open educational trails and bicycle paths [2,3,4].

Situated on an area of 52 acres, Father Collins Park incorporates many sustainability-focused features and has won a number of awards. Over 1200 trees and 2000 native saplings were planted to help integrate the existing woodland, maximise biodiversity, and vastly increase the ecological value of the park. Also, wetland areas were created to filter and clean the water in the park as part of a recycling system that replenishes and helps clean the lake and water features. The wetland areas mimic the characteristics of natural wetlands and create a special ecosystem that encourages greater biodiversity in the park. (Ref. 1)

This project deals with the creation of a green roof and a green area around the new headquarters of the IDOM Group (an independent multinational company that offers professional integrated services in Consulting, Engineering and Architecture around the world), located in an old French warehouse (a customs warehouse) on the Deusto canal in the port of Bilbao. It has an area of ​​14,400 m2 dedicated to offices, research and development spaces such as white room and workshop prototypes, and social spaces. (Ref 1)

As part of the EU Life+ CITYWATER project (of 3 cities), a sustainable stormwater management solution based on biofiltration was implemented in Maunulanpuisto Park in Helsinki, in order to purify rainwater and meltwater and improve water quality in the Haaganpuro Brook.
As the drainage area is heavily trafficked and paved with asphalt, high solid, nutrient and oil levels have occasionally been measured in the rainwater and meltwater entering the Haaganpuro brook. Such contamination is harmful to the fish stocks (e.g. trout) and other organisms in the brook. The biofiltration solution was the first of its kind in Helsinki. The solution also supported the City of Helsinki stormwater strategy, which aims at changing management towards sustainable solutions and states that stormwater should in first hand be infiltrated on spot, where it is created (ref. 1).

Kuninkaantammi is a new energy- and eco-efficient residential district by the Vantaa River and Helsinki’s Central Park that is in the construction phase with a dense urban design, consistent with the ecological, experiential and community requirements of modern housing. It will become a climate-smart neighbourhood for 5,000 inhabitants. Environmental factors have already been noted in the zoning of the area, and energy efficiency guides the design and building processes.
Kuninkaantammi will be a pilot project for stormwater runoff management in Helsinki using green infrastructure. The construction is ongoing (2013-2025). Management of storm waters in the area will be carried out through natural methods (ref. 1, 11).

The city of Wuppertal participates as a model region in the joint research project SAMUWA which aims at developing planning instruments which combine urban drainage with urban and open space development measures. With regards to the work package C.1: open space design strategies for a water sensitive city, one focus area and proposed measure, namely the "Varresbecker" flood channel is of special interest since it has been subject to comprehensive implementation plans in Wuppertal so that its implementation can be expected in the next years (Ref. 1, 2, 4 and 5). Alongside the water channel, a recreational area will be created with information to raise awareness about water management issues and climate change. (Ref. 2)

The Salitre Garden was a public park inaugurated in 1994 and built around the area of the former gunpowder factory. For this reason, it is also known as the Garden of Gunpowder (Ref 2). It is a green space planned in the urban centre, that has gone through different rehabilitation and remodelling stages. The first one was in 1987 when the land was bought by the municipality and made into the park (Ref 2 and 3). The second one was in 2012 by covering a green space around the powder factory (Ref 5). Another one was the inclusion of a new green labyrinth was installed in 2017 (Ref 4). The last one was in 2020 when a new botanical garden will be created on the island, with an open-air gym and a children's area (Ref 8).