The city’s Grünlandkonzept (green space strategy) provides detailed strategic indications for local land use and infrastructure planning (Stadt Linz, 2013). Enhancing and protecting urban green areas is seen as a way of increasing the city’s attractiveness, and will also form part of the upcoming transformation of the city harbour area. Linz AG, a holding company owned by the municipality, is planning to position the harbour on the Danube river as an important regional and international business location, inter alia by means of intensive greening for parts of the area (Masterplan Linzer Hafen, 2017).
NBS policies in the city of Linz are driven by the Urban Development (Stadtplanung) Department, which incorporates biodiversity protection strategies in urban planning goals. Activities are planned using statutory planning instruments, without seeking systemic innovations.
Although NBS are not the explicit focus, the city follows, throughout its urban planning strategy, a greening approach which results in nature-based solutions to address development problems.
NBS project 1: Landschaftspark Bindermichl-Spallerhof
The city has created a landscaped park area of 8 ha over a highway tunnel. The area is divided into different functional zones, including playgrounds and sports facilities. It serves as a recreation space for two nearby residential areas.
NBS project 2: solarCity
The new solarCity residential area was developed on the outskirts of the city, in a rural area close to an ecologically important wetland. The buildings of solarCity achieve high energy-efficiency standards compared to those that were common during the planning and construction period, and the area is well connected to the city centre by public transport. In order to protect the nearby sensitive areas, situated in the floodplains of the rivers Traun and Danube, a landscape park was designed between the settlement and the floodplains; this meets residents’ recreational needs without compromising the protected landscape close by. The landscape design included the extension of a small lake and the renaturation of a small river. Rainwater in solarCity is collected separately from the sewers, in open green ditches.
NBS project 3: Urban greening strategy
The municipality systematically develops green areas within the city and on the outskirts, in order to increase recreational opportunities for residents and improve the quality of urban life. Besides traditionally designed green areas like urban parks, innovative types of open space have also been created (for instance the urban beach on the banks of the Danube River, and the greening of the industrial area of the harbour). During the 1990s, the city started to change existing land use/development plans for the inner city area, in order to protect green areas within housing blocks by prohibiting in-fill, preventing the laying down of impervious surfaces in courtyards, and requiring the creation of vegetated surfaces over underground garages and in courtyards (Alter Bebauungsplan „O100/II“ | Innenhofgrün, 2017). The recent plan for the reorganisation of the harbour area is intended to create areas for recreation which are accessible to the public. These areas will in part be situated at ground level, providing access to the water, and in part on the green rooftops of new warehouses (Projekt Neuland, 2017).
Urban greening used by the city of Linz as a strategy for urban regeneration and growth makes the management of conflicts between investment interests and the goals of protecting biodiversity and green spaces potentially difficult to manage. Although the strategy creates qualities which are crucial for attracting economic activities, competition for land, especially in the inner city areas, can lead to such conflicts, which then need to be resolved without compromising the overall goal of restarting urban growth.
The solarCity development has benefitted from national funding as well as from ERDF funds.
With a population of 193 814 inhabitants (2014), the main challenge for the city of Linz is to manage the transition towards a post-industrial city by conserving and enhancing green spaces while providing opportunities for new development and housing. Challenges to be addressed by NBS and recognised by the local authority focus mainly on improving recreational opportunities in the city. Conservation of biodiversity, while acknowledged as a goal, appears to be subordinate to this primary goal for most green areas. Climate change is addressed explicitly only in terms of mitigation of emissions; nevertheless, green infrastructure is used to address the main current and future climate impacts on the city (heat, flooding, intensive precipitation, loss of biodiversity).
NBS project 1: Landschaftspark Bindermichl-Spallerhof
The park is intended to meet the recreational needs of different social groups living in the nearby residential areas, while at the same time creating space for biodiversity and improving the microclimate. Covering the highway (which was the impetus for establishing the park) protects residential areas from traffic noise.
NBS project 2: solarCity
solarCity has been designed as a green settlement. In addition to an increase of green/blue areas in the settlement and ground water replenishment, the solution for rainwater discharge in solarCity creates economic benefits on account of the reduced discharge into the public sewer system (Lechner and Koblmüller). Green areas have been created to divert recreational activities from the nearby sensitive floodplains of the rivers Traun and Danube. The development explicitly targets middle-income families (Lechner and Koblmüller); the creation of a high quality urban landscape and the design of the surroundings thus translate into high real-estate values.
NBS project 3: Urban greening strategy
The municipality’s urban greening strategy highlights recreational functions as the primary goal for the development of green areas. In those cases where the design of green-blue areas focuses, for instance, on renaturation of water bodies, measures seek to reconcile recreational use with the goal of conserving biodiversity. Trade-offs between the two are generally resolved in favour of recreation (any damage to nature will require repair action). Impacts generated by green areas in terms of air quality and pollution reduction, or the mitigation of the urban heat island effect by creating and enhancing ventilation corridors may be recognised (see, for instance, Stadt Linz, 2013), but are not emphasised (interview with Kolouch, Linz City Administration). In some cases, the city’s strategy indicates green areas with specific service functions, such as buffer zones close to emission sources, ventilation corridors for reduction of heat stress in the inner city area, or space for agriculture (Stadt Linz, 2013).
The Urban Development Department (Abt. Stadtentwicklung) incorporates biodiversity protection strategies into urban planning goals. The urban greening activities are planned using statutory planning instruments, without seeking systemic innovations. Strategic urban planning includes a dedicated plan for greening (Stadt Linz, 2013).
The city’s land acquisition strategy is also used, together with supporting housing policies, to protecting green areas; this means that the Municipality of Linz acquires land in order to conserve green and blue areas; this strategy has been employed systematically since the late 1980s for important forest and green areas (Linz - Presse - Rund die Hälfte des Stadtgebietes besteht aus Grünland & Wald, 2017).
Public (city) ownership
Green and blue areas
Woodland and forests
Protected area Traunauen
 Traunauen is a protected area of meadows/wetlands along the river Traun.
The city of Linz uses the statutory channels for public involvement in urban planning processes, as well as periodic satisfaction surveys (Stadtforschung Linz, 2017).
The GREEN SURGE case study report (Hansen, 2015) mentions citizens’ initiatives criticising the local authority’s greening policy as not being sufficiently rigorous in the event of conflicts between investment in new buildings and conservation of existing green, especially mature trees. Trees, with their highly symbolic value, are at the heart of disputes between the public and investors. Several citizens’ initiatives have gone further than simply denouncing cases of – unnecessary — tree felling in various parts of the city, justifying their protest in certain cases by quantifying the ecological (air quality), social (psychological well-being) and in part also economic benefits provided by trees. One citizens’ initiative sought a legal basis in the form of a local charter for the protection of trees (Ortbauer, 2014).
The GREEN SURGE city report (Hansen, 2015) also names bottom-up urban greening initiatives, such as temporary community gardens on underused or derelict land (Freiraum Linz, 2017), supporting free fruit picking while mapping fruit trees (Linz pflückt), establishing a beach along the river Danube, and initiating a public and international debate on the revitalisation of the deindustrialised eastern part of the city (including abandoned green roofs on industrial buildings) and their function for a new and sustainable form of urbanisation.
The city administration has created an online tool for members of the public to make suggestions for action — mainly with regard to maintenance of public spaces and parks; the tool can be used with smartphones (Schau Auf Linz, 2017).
 Linz.pflueckt.at | Linz Pflückt visualisiert die Standorte der Obstbäume der Stadt Linz, 2017).
The overall public strategy for urban greening is intended to improve the city’s attractiveness with a view to attracting new economic investment, as well as tourists. It is difficult to measure the impact of this strategy on restructuring the urban economy, as it is one aspect of the overall image of an attractive city which is well-landscaped.
Deindustrialisation has created windows of opportunity and pressure to give the city a new image. The city’s successful application to be European Capital of Culture in 2009 was used for the same goal (Linz 2009 European Capital of Culture - The Goals of Linz09, 2017).
As part of a national research programme on technologies for sustainable development (Nachhaltig Wirtschaften), initiated by the Austrian Federal Ministry of Transport, Innovation and Technology, the Municipality of Linz has developed a framework for evaluating urban development schemes, entitled ‘LES — Linz entwickelt Stadt!’ (Linz Develops City). The framework comprises a catalogue of target criteria for sustainable urban development that can be used for evaluating large construction projects, including a summary of general requirements for sustainable urban development, social aspects, aspects relating to energy and environmental performance, economic factors, and mobility issues. It is designed for easy use within a city administration structure by means of a database tool suitable for networks (Linz - Life - Evaluation, 2017). The framework was used to carry out a sustainability check of solarCity at the end of 2005, following completion of the first phase of construction (Lechner and Koblmüller).
While GREEN SURGE (Hansen, 2015) has analysed initiatives and projects in Linz, the city has not participated in any further EU projects focusing on urban greening. Furthermore, for the Municipality of Linz, activities by GREENSURGE did not entail implementation of NBS projects, but were limited to analysis of NBS related policies in the case study city, and the analysis had no further impact on the city’s policy.
Gunther Kolouch, Magistrat der Landeshauptstadt Linz (Linz City Administration)
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