Isar-Plan: Improving flood protection and recreational opportunities by redesigning the Isar

Wasserwirtschaftsamt München
Published: 21 September 2017
Last edited: 22 September 2017
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Summary

The project group “Isar-Plan” was initiated in 1995 to restore the Isar river in Munich from its artificial canal bed to a more natural shape and function in order to improve flood control, biodiversity and recreational opportunities. Construction started in 2000 and was finished in 2011 having restored 8km of river and costing 35 million euros.

Classifications

Region
West and South Europe
Scale of implementation
Local
Ecosystem
Freshwater ecosystems
River, stream
Urban Ecosystem
Urban wetlands
Theme
Adaptation
Cities and infrastructure
Disaster risk reduction
Ecosystem services
Flood management
Habitat fragmentation and degradation
Health and human wellbeing
Restoration
Urban planning
Hazards addressed
Floods
Loss of biodiversity
Sustainable development goals
SDG 6 – Clean water and sanitation
SDG 11 – Sustainable cities and communities
SDG 13 – Climate action
SDG 15 – Life on land
SDG 17 – Partnerships for the goals
Aichi targets
Target 2: Biodiversity values integrated
Target 15: Ecosystem restoration and resilience
Target 19: Sharing information and knowledge
Sendai Framework
Target 4: Reduce disaster damage to critical infrastructure and disruption of basic services, among them health and educational facilities, including through developing their resilience by 2030

Location

Munich, Germany

Challenges

Heavy rain events in the Alps in the years of 1999, 2005 and 2013 led to major floods and substantial financial damage in the South of Germany. Such events are likely to increase with climate change. Furthermore, balancing societal and ecological priorities as well as working to remodel the densely populated inner city to implement the river restoration plan was challenging, with disagreements over the design in certain areas as well as what was feasible within the confines of the city.

Beneficiaries

Given the improved flood protection and the quality of nearby recreational spaces, the main beneficiaries are the surrounding infrastructure, citizens and visitors to the area as well as the economy. The restoration also benefits biodiversity.

How do the building blocks interact?

Strong partnerships and public engagement (building block 1) are essential for the successful implementation of the solution and a prerequisite to allow for multiple goals to be achieved through balancing trade-offs (building block 2). Finally, “learning by doing” (building block 3) allows for improved solutions.

Impacts

The project successfully improved protection against flooding through developing more of a natural river landscape, which allows space for the river. Indeed, a big flood in 2005 had an effect on the whole catchment area and allowed evidence to show where the restoration had mitigated flood damage. As seen through the impacts of this massive flood in other areas of southern Germany, the restoration of the river Isar has improved flood control and reduced the damage that could have been caused.

 

The project has also benefited biodiversity through the creation of new habitats for flora and fauna and through allowing fish to move along the river where before they were impeded.

 

The hydrological status has been also improved to achieve bathing water quality. This means that Munich inhabitants and visitors can swim in the river and benefit from the attractive landscape for many recreational activities.

Story

Wasserwirtschaftsamt München

The Isar river restoration along 8 km in the city of Munich is a spectacular achievement in its ability to accommodate both large floods that regularly impact the area and high recreational usage with up to 30,000 people gathering in the area on warm weekends, while improving biodiversity.

 

The project group “Isar-Plan” was initiated in 1995 during an investigation of the Munich flood protection systems and amidst an increasing demand for a “closer to nature” urban environment which can offer recreational opportunities. The project was headed by Munich City and the Bavarian Water Board and represents an unparalleled level of interdisciplinary cooperation. After preliminary studies in how to design a project that balanced the aims for flood protection, ecology and recreation, work started in 2000. The main channel was widened from 50m to 90m and a number of measures have been undertaken to restore the natural hydrological function, a near-natural appearance of the river, with ample habitat for flora and fauna and recreation areas, while at the same time ensuring flood protection of the surrounding area.

 

In 2003 a landscape design completion was launched with public consultation and participation for the last 1.6Km stretch in the heart of the city (that needed to take into account ecological, flood protection and recreational goals). This resulted in controversial discussions and public quarrel because two near opposing projects (an urban functional design vs a total re-naturalised design) were selected as first and second prize. Finally, in 2005, both teams collaborated to provide a compromised design that encompassed the secure flood protection needed within the constraints required by the heavily built up area and a renaturalised appearance.

 

The restoration finished in 2011.

Contributed by

Wasserwirtschaftsamt München Wasserwirtschaftsamt München

Contributors

Wasserwirtschaftsamt München