Among the contemporary challenges of Brazilian cities, the water issue is an urgent matter. The rapid and enormous growth of cities was not accompanied by a concurrent increase in protection against floods, nor by an increase of landscape quality in the relationship between rivers and cities. Rivers and streams are still being channelized, straightened, and concreted; public spaces along watercourses are of low quality; floods and inundations remain a problem.
More than 80% of Brazil’s 200 million inhabitants live in cities today, where efforts for sustainable development should be concentrated. As late as the 1960s, Brazil was predominantly rural. This immense and rapid urban growth has generated a conflict regarding water issues. Among the questionable strategies are obsolete drainage structures, river straightening, concreting of banks, and piping of rivers and streams, as well as occupation of flood-prone areas by both formal and informal urban development.
Considering cities as the human habitat, and urban rivers as a relationship between nature and culture, promoting good practices in the relationship between rivers and cities contributes to the sustainable development of Brazilian cities.
The Netherlands is the delta of several European rivers, and the relationship with rivers, groundwater, sea, and rain has always played a prominent role in shaping the territory and urbanization. This relationship has been established over the centuries, has changed, and continues to change in current times, determined by economic, cultural, and the perception of water. Water is no longer seen solely from a functional standpoint but now entails a more integrated approach encompassing natural processes, landscape, social, leisure, and recreational aspects that are part of human needs.
Within a context of climate change and a future of uncertainties, where traditional engineering solutions are no longer sufficient for urban water management, cities must prepare and become more resistant, more resilient, and, above all, more adaptable. Learning from Dutch experiences in this regard provides valuable lessons to move towards a more balanced relationship between cities and rivers, with appropriate contextualization within the Brazilian reality.
Three projects underway in the Netherlands stand out for their applicability to the Brazilian context: Water Squares, The River as a Tidal Park, and Room for the River, as discussed below.
Water Squares
The water wealth of our country has generated hundreds of cities situated along rivers and watercourses, and urbanization creates a mismatch in the water cycle.
The rapid process of Brazilian urbanization, combined with a tropical climate condition with high precipitation, has resulted in an obsolete drainage infrastructure that is no longer able to manage the amount of rainfall we experience in the built environment.
The traditional solution focuses on upgrading the structure: river canalization and increasing pipe diameter.
“But what are the additional values that can arise from a purely functional perspective? The need for water management also generates a series of opportunities,” says Taneha Bacchin, brazilian researcher and coordinator of the Delta Urbanism research group at Delft University of Technology. “We should consider updating this structure but doing so under a new paradigm, redesigning the urban context to store water in space, with a combination of open space and underground.”
Instead of upgrading the structure in the traditional way, a costly process that bores the population (with the closing of streets) and lacks political appeal (since the piping is hidden), she suggests maintaining the existing networks but including landscaping of open space, detention areas, water spaces – spaces that will only be flooded when necessary. It’s a process of decentralization, including blocks and plots that are no longer connected to drainage. “We should think about hybrid structures. Not disconnect everything, but include open spaces.”
A good practical example of applying this concept is the Water Squares project in the city of Rotterdam, Netherlands. These are sports courts for public use, but they also function as water holding areas in case of heavy rain. Even the design and painting of the courts emphasize the multifunctional nature, through a painting in shades of blue, resembling a swimming pool, so that the population recognizes it as such. “It’s a detention basin as part of urban design,” explains Taneha.
The multifunctionality of green and blue infrastructure should be considered in Brazil. Adding to a functional structure environmental values, such as natural and landscaped areas, and social values such as parks and courts, is also a more economical solution for Brazilian cities. This is solving problems sustainably through urban design.
Picture 01 – Water Squares – Project
Source: http://www.urbanisten.nl/wp/?portfolio=waterpleinen Access on May 25, 2017.
Picture 02 – Water Squares – Real photo on site.
Photo: Walter Weingaertner.
The River as a Tidal Park
“The riverbanks are a balanced mix of nature and culture” (De Urbanisten)
A special feature in the Netherlands is the presence of canals. About 2/5 of the Dutch territory is below sea level, made possible through the construction of dikes, dams, and canals. In this way, the presence of water in the Dutch landscape is constant.
According to architects from the “De Urbanisten” group, the Rotterdam region has over 360 km of riverbanks; however, about 70% of these are considered “hard”, meaning they are lined with stones, concrete, or other materials, turning the rivers into mere water drainage channels. Only 10% of the riverbanks can truly be considered natural. Consequently, environmental and social functions are severely limited.
The project “The River as a Tidal Park” seeks to redesign the transition between the river and the city. The idea is to bring nature to the edges, with the reconstruction of riverbanks, fauna, and flora, and the necessary conditions for these, such as food and shelter for animals.
For a long time, the river was seen only as a function – transportation, port, drainage, for example – which has changed considerably in the last 25 years. The canals are subject to tidal flows and ebb tides. “The river needs room for its natural behavior, including about 1.5 to 2m of oscillation,” says Professor Han Meyer of Delft University of Technology. “The project creates more conditions for nature, emphasizing the transition – important for natural ecosystems – and bringing recreational areas into the city center.”
The integration of structure and landscape is a characteristic of contemporary projects, where the landscape can be interpreted as a new way of designing infrastructure. Taneha Bacchin states: “We must think about multiple benefits with environmental inclusion, within the scope of urban and river revitalization.” Thus, new projects must be attentive to landscape design, which encompasses natural ecosystems. This brings a series of additional advantages, such as water and air quality, noise reduction, and consequently, additional benefits for humans. The benefits for physical and mental health, such as outdoor sports activities and stress reduction, and for social activities, such as leisure and meeting opportunities, are even the subject of environmental economics studies. Studies place financial values as arguments, in terms of health spending and real state valuation, for example – since unfortunately, part of the population still does not recognize the importance of environmental and social issues.
Picture 03 – The River as a Tidal Park – The hard banks at Rotterdam’s canals.
Source: http://www.urbanisten.nl/wp/?portfolio=river-as-tidal-park Access on May 25, 2017.
Picture 04 – The River as a Tidal Park – Project
Source: http://www.urbanisten.nl/wp/?portfolio=river-as-tidal-park Access on May 25, 2017.
Room for the River
The Dutch program “Ruimte voor de Rivier,” also known as “Room for the River,” aims to give more space for the waters, so that the river itself can manage its waters in case of floods.
The Delta region is highly sensitive, both from an ecological perspective and due to human pressures for coastal use and occupation. Moreover, upstream interventions reflect more intensely downstream. It is along the Dutch coast that three important rivers converge: the Rhine, Meuse, and Scheldt. “The Rhine is heavily urbanized in all its extension, and the problems that erosion entails are concentrated in the Netherlands,” says Professor Han Meyer of the town planning department at Delft University. “It takes national organizations that have the responsibility to manage water, and also at the European level.”
After the major floods of 1993 and 1995, with 250,000 people evacuated, and in the context of climate change, the Dutch government took measures within a new approach. “It is a project of the ministry that says ‘no’ to traditional engineering and says ‘yes’ to non-works, to opening the riverbeds,” explains Taneha Bacchin. “Traditional engineering processes are not sufficient in the face of uncertainties (such as climate change), and recent experiences show us that we need to learn from natural processes.”
Professor Meyer adds: “There were public policies for population distribution, but in the last 15 years, within a government policy of not take care of personal lives, big cities are growing again and urbanization is growing in risk areas. The question is ‘how can we maintain good living conditions and keep people safe. how can we maintain good living conditions and keep people safe. That is what delta urbanism is about.”
In more than 30 points across the country, measures have been taken to ensure that the river can safely flood. As each river and each stretch have peculiar characteristics, each solution is tailor-made. The illustration below presents some of the key steps taken, such as the removal or relocation of landfills, dikes, and structures.
But that’s not all. Other additional values have been brought to light. A good example is the city of Nijmegen, which additionally gained a large public park in areas that may eventually be flooded. Initially, the population was against it because there were many resettlement conflicts, for example. But today, the population is quite satisfied, with the addition of public spaces for leisure and social gatherings. And finding this combination of security, well-being (economic and social), and ecology was the great challenge of the project. “For a long time, we only considered safety and the economy. But if we don’t pay attention to ecological issues, the delta takes back. We need to find a new balance,” says Meyer.
“Pay more attention to river, not only as something dangerous, or very important from a functional perspective (because it is a transportation corridor), but especially pay attention to its natural characteristics, ecological life related to the river, and the way that the river can play a role for the leisure of citizens,” he concludes.
Picture 05 – Room for the River – main solutions.
Source: https://www.ruimtevoorderivier.nl/english/ Access on May 25, 2017.
Contemporary Netherlands deals with water towards an integration between natural processes and human needs, whether social or economic.
The Water Squares project shows a hybrid solution between conventional drainage structures and new structures that serve as landscaping or leisure areas, which may eventually be flooded. A more economical solution with fewer disruptions to update drainage structures – and with additional gains in quality of life for citizens.
The River as a Tidal Park project focuses on the renaturalization of rivers and banks, which over the centuries have been straightened and stabilized, as a way to bring nature back to urban centers while bringing more recreational areas to cities.
The Room for the River project understands that, in cases of floods, the most efficient solution comes from promoting more space for the river to flood, a vision almost opposite of what was practiced decades ago.
For the Brazilian reality, the richest country in water and biodiversity in the world, and still lacking in social policies, the three mentioned projects serve as inspiration for a more sustainable future.