A nearly fifty year-old urban policy combining health, ecology, and cultural motivations for changing the use and planning of urban rivers
Context
“When we forget we are embedded within the natural world, we also forget that what we do to our surroundings, we are doing to ourselves.”
Rivers—particularly in urban areas—demonstrate societal attitudes towards our relationship with nature. For hundreds of years, rivers were used as ‘“sinks” in densifying cities: handy devices for removing unwanted things from the surface, such as wastewater, industrial effluent, and human sewerage. This often resulted in the death of rivers as ecosystems, with both loss of habitats and danger to human health as they became fetid corridors that only transmitted disease—such as in the great stink of London in 1858—rather than being valued as living parts of the city. A typical response to such events was the covering of urban streams and rivers, or ‘culverting’ in underground tunnels so that many cities lost a large proportion of their visible rivers that were combined with underground sewers, buried beneath the pavement and fading from memory. Many of the remaining above-ground rivers persist as unhealthy environments, particularly in countries like the UK with poorly-regulated private water companies.
In the years since, the need for healthy waterways becomes more apparent, as the relationships between healthy river ecosystems and urban biodiversity have been more comprehensively studied. Urban rivers are also valued as places of transportation, recreation, and as a way of connecting with nature: places where wellbeing and collective experience converge with planetary health and climate. Rivers connect places and systems beyond man-made boundaries, and bring various ecosystems together—requiring planners to think about the interdependency of places and the reliance of cities on places and processes far outside their supposed limits.
Practice
In response to growing awareness around the environmental importance of rivers, Swiss cities such as Basel, Bern, Zurich, and Geneva have been at the forefront of transforming their river fronts into accessible public spaces over the last few decades. This transformation has involved waterways that were previously reserved for industrial use that are now regularly enjoyed by the citizens for more than recreation. A prime example of this is Zurich’s “Bachkonzept” or Stream Daylighting Policy. The city recognised that by mixing clean water into combined sewerage and surface water culverts, water was being contaminated unnecessarily, increasing the load on wastewater treatment plants down the line. First presented in 1988, the Bachkonzept proposed simply separating sewerage channels from urban rivers and uncovering, deculverting, or ‘daylighting’ freshwater streams as part of biodiverse urban landscapes.
The catalyst for the scheme was the introduction of a Federal Act on the Protection of Waters (WPA) in 1991, which—through a number of provisions on the preservation of health, habitats, and landscapes—effectively mandated the re-separation of sewerage and freshwater channels. In the decades between the introduction of the law in 1991 and the retirement of Fritz Conradin—the head of sewerage who spearheaded the programme—in 2003, the city revitalised 24km of waterways through a combination of daylighting and renaturalisation. This has led to a dramatic reduction of wastewater processing, providing an economic justification for the entire process, as well as myriad benefits in terms of biodiverse habitats, leisure opportunities, and environmental health.
The practice of reclaiming urban waterways, through a variety of initiatives such as waterfront revitalisation, greenways and parks, public access to beaches and waterways, and urban fishing/boating, creates sustainable relationships between people and their environment, and encourages a greater appreciation of urban ecosystems. In other Swiss cities, river swimming has even become an option for the daily commute, as people use the swift currents to get to work. Such projects are often hard-won, the culmination of a sustained process of negotiation between citizens, institutions, and government, often initiated at a local level.
Bachkonzept is a pioneering form of hybrid green-blue infrastructure that combines natural systems with an understanding that everyone has the right to access and claim natural resources in urban environments. By enshrining strong principles in legislation—developed in response to citizen-led environmental movements—and implementing these principles through local policies, the approach goes far beyond a single project and instead has the potential to make holistic and long-term change to a country’s attitude to waterways, both infrastructurally and culturally. These revived rivers become important markers of the interdependency of ecological systems: what manifests in the city as a nexus of leisure and health is only possible through engaging with natural and artificial systems upstream and downstream. They are thus examples of a relational approach to spatial planning in the face of climate breakdown.