Improved stormwater management

Following a severe storm in 2000 that overwhelmed the sewage system of Portsmouth along with its main Wastewater Pump Station, causing major flooding in the city with the destruction of private and public properties, prevention of such events become a key priority (5).
The Portsmouth Flood Alleviation Scheme aims to relieve the pressure on the sewage system in wet weathers by diverting the accumulated surface water flows away from the combined sewer networks and discharge them into the harbours around the island (5). The Scheme consists of several measures across the city, among others the creation of a new open watercourse channel across the Great Salterns Golf Course diverting surface water directly into Great Salterns Lake (5). This measure of the scheme is a solution that separates surface water to provide resilience, boost flood protection and benefit the environment with the minimum of new infrastructure (1).

New recreation zone "Norikus Bay" in Nurenberg was completed in 2018 on the south bank of the Wöhrder lake, an artificial lake created in 1968 to protect the city from flooding. The dam itself, which is a 400m long path separating a part of the water surface from the bigger part of the lake, has become a tourist attraction with a water playground and other recreational amenities being offered. The water is naturally cleaned through the regeneration zone with natural plant filter, and simultaneously improves the habitat of fish and makes recreational swimming in possible in the cleaner water. New green areas are organized on the shore in order to improve environmental, aesthetic and recreational conditions of the area (1, 7, 8).

Park Track North (Park Spoor Noord) is built on a former railway territory and was aimed to provide a social, green and mobility 'corridor' as the territory disconnected parts of the city (Ref. 1,4). Now, the park has a sustainable drainage system, allows a maximum diversity of people to use the park and has trees that will last for a long time. The park is further considered sustainable because of the use of FSC wood, re-used materials and energy-efficient lighting while the historical railway elements are restored or reused (Ref. 1,7).

Focus Park is a large shopping mall with green terraces (900 m2) and green walls in the city of Bydgoszcz. The project serves marketing purposes – the green areas outside the mall are visible from various vantage points. Due to the selection of pollution resistant plants and installation of an automatic irrigation system the project also involves water retention and supports local biodiversity and good air quality [1].

The green roof and courtyard/patio on a new campus building of the University of Applied Sciences consist of trees and plants that reduce temperature and improve air quality. The plants are grown on a thick substrate layer that allows for extra stormwater storage. The vegetation also provides habitat for species such as insects, filters particulates from the air and reduces noise, and creates aesthetic value for patients in a nearby hospital (Ref. 1).

Instead of expanding the Ring of Antwerp to improve mobility, the municipality of Antwerp decided to use the space to create a Green Ring of 13 kilometers consisting of a wide range of projects (Ref. 3). This large city plan contains green spaces along the Ring, green corridors between those green spaces and with existing parks, a new green park, neighborhood green spaces, restoring the historical city wall and so on (Ref. 3). The plan also contains measures to improve water storing capacity (Ref. 4).

Fobney Island in Reading (which is an area by the River Kennet in Berkshire county) was transformed through a restoration project in order to e.g. attract wildlife (birds; bats; water voles; otters). This partnership project (with work being carried out by the Environment Agency, Reading Borough Council, Thames Water and the Thames Rivers Restoration Trust), includes restoring the river and creating wetlands. (Ref. 1-3)

A roof garden of about 370 square meters was built on the new building of the Diakonissenklinik in the course of the general renovation. The new intensive greening of the roof can be seen from many hospital wards and serves as an additional recreation facility for its patients (Ref. 1).

Thanks to an initiative by the citizens of Sofia, called Green Rails in Sofia, grass was planted by the Municipality on a an area of newly reconstructed tram line in Sofia. The cited benefits were heat reduction, noise reduction, aesthetics, natural water retention and drainage, and lower costs of maintenance in the long term compared to grey alternatives. The grassroots initiative “Green Rails in Sofia” are determined to keep putting pressure on the local authority to continue planting grass on other parts of the tram lines. (Ref. 1; Ref. 2; Ref. 3)

'Groene Mient' (Green Commons) is a citizen initiative that realized an exceptional social-ecological residential project consisting of three housing buildings of energy neutral homes and a 3,500 m2 communal garden (1,6). Storm water is captured from the roofs of the buildings into bioswales, permeable paving is applied, the shared garden is 'eatable' and houses run on sustainable energy (1). The houses do not have a gas connection and have three different sustainable energy systems: heat pump with heat-cold storage, solar boiler or electric heating (6).