River Liesing, Vienna

Restructuring and renaturalisation of a former 70ies "Concrete bed river" in the City of Vienna according to the European water directive

Name	please enter the name here
Place	please enter the town/area name
Country	please enter the country here
Topic	please enter the topic here
Author(s)	Please enter your name(s)
Completion	Please enter the date of completion
Client	Please enter the client
Project costs	Please enter the costs (if known)


<googlemap version="0.9" lat="48.204998" lon="16.246719" type="satellite" zoom="11" width="300" height="250"> </googlemap>

Rationale: Why is this case study interesting?

Please summarise:- e.g. Design Innovation? Planning Exemplar? Theoretical Insights? Lessons learned from its failure? [It doesn’t have to have been successful]

Think about it from the view of another educator/student in a different country. Why should I use this case study in my teaching/education?

Author's perspective

What theoretical or professional perspective do you bring to the case study?

Landscape and/or urban context

Biogeography, cultural features, overall character, history and dynamics

Illustration: Map; sketches; short descriptive analyses

The river Liesing is located in the South of Vienna. It has two souces, the “Dürre Liesing” and the “Reiche Liesing”. While the Dürre Liesing arises from a limestone area, the Reiche Liesing arisies from the flysch limbestone area of the Wienerwald, which makes the river grow rapidly in case of heavy rainfall, this lead despite the strict regulation in a concrete river bed to the river bursting its banks. In Vienna river Lising has shaped the landscape through meanders, deposition of sediments and erosion earlier, but after a havy regulation in the 50ies followed by an even stricter regulation in the 70ies it was forced in the staight river bed, which lead to a low biodiversity and to the river running quickly. After housing development in the areas around the river, mainly in the 90ies, first attempts to rearrange the surrounding and to adapt it to the new user needs were atarted, after two major fluds in the 90ies, and the implementation of the European Water Directive the City of Vienna decided for the revitalisation of a 5,5 km area of the river to be completely renewed and revitalised.

Cultural/social/political context

The Policy background of this project is the implementation of the European Water Directive 1 The purpose of this Directive is to establish a framework for the protection of inland surface waters, transitional waters, coastal waters and groundwater which:

(a) prevents further deterioration and protects and enhances the status of aquatic ecosystems and, with regard to their water needs, terrestrial ecosystems and wetlands directly depending on the aquatic ecosystems; (b) promotes sustainable water use based on a long-term protection of available water resources; (c) aims at enhanced protection and improvement of the aquatic environment, inter alia, through specific measures for the progressive reduction of discharges, emissions and losses of priority substances and the cessation or phasing-out of discharges, emissions and losses of the priority hazardous substances; (d) ensures the progressive reduction of pollution of groundwater and prevents its further pollution, and (e) contributes to mitigating the effects of floods and droughts

Government bodies of the EC member states are requested to implement the directive into national law and to identify river basin districts and responsible authorities (Art. 23, Art. 3) until 2003. The basic units of the directive have to be defined until end of 2004 (Art. 5). A monitoring network has to be established and accompanied by public relations work until 2006. In 2008 draft river management plans have to be in a form to be presented to the public. For 2009, the finalised river management plans should include milestones and an implementation plan to achieve the specific objectives (Art. 13, Art 11). Following this timetable it is expected that member states of the European Union will meet the environmental objectives in 2015.

History

The aim of the project was to improve the situation at the river Liesing according to the EU Water Directive in order to archive “maximum ecological potential” of a heavily modified water body.

The specific aims of the projects were: • Improvement of the water quality to quality class II according to the saprobic system. • Re-introduction of a diverse macrozoobenthos and river-specific fish species into the relevant river section. • Establishment of a string of aquatic ecosystems with restored ecosystem function and structure which may function as aquatic ecological corridor extending far into the urban area. • Creation of new habitats for priority species (council directive 92/43/EEC on the conservation of natural habitats and of wild fauna and flora). • International exchange of project results.

After valuation of the actual state, a project structure has been developed by the landscape architecture office Knoll and the City of Vienna, Departments 30 and 45.

The area has been divided into 4 sections, the following landscape architecture offices in Vienna were comissioned to design the areas according to the master plan by office Knoll