Water vs. Urban Scape

WATER VS. URBAN SCAPE Exploring Integrated Water-Urban Arrangements

MARCO RANZATO (ed.)

Table of Contents

7

Preface Marco Ranzato

11

Introduction: the Water-Urban Dilemma Marco Ranzato

25

Designing for Diverse Urban-Waterscapes

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Diffuse Water in CittĂ Diffusa Marco Ranzato and Giambattista Zaccariotto

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Reimagining the Relationship Between Cities and Water: an Australian Perspective Dave Hedgcock and Mike Mouritz

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Grafting on the Water Landscape in the Dispersed Urban Territory of Flanders Christian Nolf and Bruno De Meulder

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Oslo Water Sensitive City.

A Design Approach for Transition Giambattista Zaccariotto

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Making City. ArnavutkĂśy, Istanbul Sotiria Kornaropoulou, Jaap van der Salm, and Dirk Sijmons

115

Conceiving Water Space in Kigali: Difficulties and Opportunities in Shaping the Informal City Ilaria Boniburini

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Rediscovering the Water Network for Enhancing the Pedestrian System of Shanghai Tongyu Sun

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Designing the Brussels Urban-Waterscape

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Brussels Urban-Waterscape Marco Ranzato

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Brussels’ Visible Water Marco Ranzato, Alessandra Marcon, Simone Conz, Liu Siyu, and Zhao Yang

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Towards New Urban ‘Hydrographies’ Alessandra Marcon and Marie Pire

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Brussels’ Heterogeneity for Water Marco Ranzato, Roberto Genna, Pauline Cabrit, Maëlle Thueux, and Wu Xiaoyu

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Integrated Water Systems in Heterogeneous Urban Areas Martina Gentili and Andrea Aragone

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Water Following Brussels’ Socio-Topography Marco Ranzato, Marta De Marchi, Simone Conz, Yixin Xu, and Bianca Fanta

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Water Management in the Light of Social Topography Marta De Marchi

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Brussels’ Water Courses Retrofitting Marco Ranzato, Catalina Codruta Dobre, Simone Conz, and Olivia Adamska

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Retrofitting Urban Rivers in Dense Areas: Urban Space as a Critical Resource Andrea Bortolotti, Catalina Codruta Dobre, and Luisa Moretto

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Brussels’ Heterogeneity and Fragmentation via Topography Géry Leloutre

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Epilogue: Designers’ Dreams and Urban Water Sybrand Tjallingii

Marco Ranzato

Preface

This book is mainly a collection of design experiences around the current urbanisation and the arrangement of its waters1. The idea came about in the frame of the workshop Water vs. Urban Scape? Exploring integrated and decentralised arrangements of water in the Brussels Capital Region held in Brussels in July 2013. Organised by the Faculty of Architecture La Cambre Horta of the UniversitĂŠ libre de Bruxelles in collaboration with the College of Architecture and Urban Planning of the Tongij University, this intensive pedagogical and design experience was tutored by Latitude Platform for Urban Research and Design. Soon after, it appeared important to further develop the ‘raw materials’ worked out in the workshop and to frame them in a broader reflection regarding the role of design in the matter. The scope of the reflection expanded in a stroll round the challenges and lines of work concerning Brussels as well as those of other emblematic urban conditions resulting from the varied urbanisation processes presently changing the planetary landscape2.

In thus proceeding, the book attempts to trace a line with Hydropolis: the role of water in urban planning, a key international UNESCO-IHP workshop on the subject from 1993. Already at that time, in the urban design discourse, the concept of Integrated Water Management was gaining momentum3. Diverse researchers were launched to explore design tools and processes integrating the water issue. After about 20 years, this book indirectly acts as a foundation

7

Marco Ranzato

Introduction: the Water-Urban Dilemma

Water is an urban issue River floods, inundations, water shortage, dirty water, water pollution, drowning, etc. are not a new issue for urban landscapes and their inhabitants. This sequence of words makes water and urban appear like two antithetical matters almost as if water was an external nature from which the urban has to protect itself. However complicated the relation might appear, the need for urban areas to continuously interplay with water cannot be disputed. Whatever the way water is metabolised by the urban milieu, water and urban are indissociable. It is as simple as the following: Water is life. The water-urban binomial, however, is not a fixed ‘thing’1.

It instead “embodies a multiplicity of historical-geographical relations and processes” in continual change (Swyngedouw, 1999, p.2). The intensification of the modernisation process and the related technical progress occurred over the last centuries brought the water-urban to a profound ’relationship crisis’. It has been under the light of modernism, with its belief in linear progress (Harvey, 1989), that the water-urban production and consumption patterns have intensified massively. Since the emergence of the industrial city – and the advent of the centralised states (Cosgrove, 1990) – the exploitation of water resources has continued to rise at an unprecedented pace. Rapidly, the conviction that water can actually be completely controlled became a certainty (e.g. Cosgrove, 1990;

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main urban centre surface water spring area Ronco all’Adige case study area Veneto Region

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Figure 1. (Top) The Veneto Region in the frame of the Pianura Padana Valley, Italy.

Elaboration from B. Secchi and Viganò (2006).

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Figure 2. (Bottom) A portion of the città diffusa in the Veneto Central Area.

Source: Marco Ranzato.

500km

Introduction Towards the end of the twentieth century, researchers (e.g. Indovina, 1990; Secchi, 1991; Piccinato, 1993) described the emergence in the Veneto Region, Northeast Italy, of a specific urban system, a diffuse organisation of agricultural and urban activities (dwelling, services, agricultural fields) with different spatial morphologies and densities of fine grain2. The Veneto urban system, named città diffusa, “works like a compact city without having the same concentration and density characters”3 (Indovina, 2009, p.131). In urban history, this was a major change in the definition of what was urban and became a conceptual category adequate to deal with the complexity of current outer urbanisation in Europe (Dematteis & Governa, 2001).

In Veneto, favourable conditions of landform, climate, and water resources have been key factors contributing to the long-term dispersed inhabitation. For centuries, the pervasive and dense surface water networks – together with the road networks – have been the carrying structures of many land use activities (Bevilacqua, 1989; Bianchi, 1989; Viganò, 2008b) (Figure 1). However, along with the consolidation of the urbanised countryside into a city of dispersion (Piccinato, 1993), water problems such as floods, droughts, and pollution have multiplied, both in magnitude and type4. In the future, the water-related problems of the region could be exacerbated by forecast changing climate conditions (Zandonella et al., 2013; Pasini et al., 2012). This situation will compound the effects of the recent economic recession, whereby the micro and medium companies that since the second world war have been ruling the regional economy, are today mired in stagnation (see the regional resolution n. 552 of 15 April 2014, Regione Veneto)5.

The urgent question relating to the region’s water arrangements that fit the peculiarities of città diffusa comes at a time when a paradigm shift in water management is occurring. The alternative model being pursued is Integrated Water Management (IWM) (Mitchell, 1990). Integrated Water Management insists on a more ecological approach with comprehensive understanding of the water cycle as well as “identification and inclusion of all relevant systems and system interactions (environmental, economic, cultural and social)” (Painter & Memon, 2008, p.231). Accordingly, water resources should be managed carefully, reducing consumption while increasing reuse and recycling, at the lowest scale possible (Novotny, 2008; Tjallingii, 1996). The shift requires the provision of physical space for the storage of water as a prerequisite for its reuse and recycling.

Our hypothesis follows, that small-scale, mainly decentralised, and multifunctional water systems for water provision and collection fit the specific strongly decentralised character of città diffusa’s spatial structure (Figure 2). In terms of the IWM model, its dense interpenetration and diversity of land uses become key spatial conditions for setting up closed-loop circuits of water. These very diverse land uses require and release water flows of different qualities.

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STATE GOVERNMENT PLANNING

STATE WATER PLAN

STATE PLANNING STRATEGY

Regional water plans (Department of Water)

Region Scheme, (sub) regional strategy, or (sub) regional structure plan Includes regional water management strategies

Department of Waterplans · Statutory water management · Drainage · Drinking water source protection · Floodplan management

INTEGRATED WATER CYCLE MANAGEMENT: Catchments, regional issues, long-term water resource management and planning

District structure plan, local planning strategy or region scheme amendment Includes district water management strategy

Drainage and water management planning (Department of Water)

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WATER SENSITIVE URBAN DESIGN: Local responses, built environment focus

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EN T The above diagram depicts the optimal process. In situations where there is existing zoning and a lack of guiding information, a flexible approach to implementation may be required. This is at the discretion of the WAPC on advice of the Department of Water.

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Figure 5. Better Urban Water Management – integrating land and water planning. Source and ©: WAPC,

LOCAL GOVERNMENT PLANNING

2008a Better Urban Water Management, WAPC, Perth.

From drainage to Integrated Urban Water Management One of the outcomes of the research that was carried out on water sensitive design highlighted the limitations placed on water management once key drainage infrastructure was established (Hedgcock & Mouritz, 1989). For example if a decision had been made to drain land to release its urban development potential – thereby fundamentally altering its hydrological regime – there is very little that can be achieved at a detailed design stage to meet water sensitive design objectives. Accordingly much work has been undertaken in Western Australia to incorporate water management issues into the initial stages of strategic planning for future land releases. The vehicle for achieving this is through strategic urban water management strategies and plans that are now an environmental pre requisite for future development assessment. This process has become guided and reinforced by policy documents such as Better Urban Water Management (WAPC, 2008a & b). This process clearly establishes the requirement for integrating water and land planning and assigns responsibilities across the various actors, be they state agencies, local government or the private developer (Figure 5).

For the low lying land that forms much of the land bank for future urban development in Perth this involves developing engineering responses that engage with the hydrological characteristics of the area and treat these characteristics as a very real constraint on future development including the dimensions of its design. Typically this may involve; the protection of natural stream lines, the reservation of adequate land to internalise drainage regimes – generally in constructed wetlands or damp lands and the use of public reserves (such as roads) to achieve water management objectives.

These approaches to integrated urban water management essentially provide the groundwork to effectively apply a range of design responses that more effectively link the character of the natural water environment to the character of the finished urban form providing a distinctiveness that is often missing in conventional suburban settings (Figure 6). However, such a change in suburban form does face resistance from a conservative community that has clear expectations of what a suburb should like. Having damp lands replacing landscaped verges – albeit that such conditions would be limited to one or two months of the year – represents a considerable marketing challenge for the development industry. To date, fully ‘water sensitive’ suburbs have yet to be developed with developers instead utilising more conservative elements of the water sensitive design suite (Ringvall, 2014).

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Figure 3. Printing plate. The comparison of the present urban grain with historical maps shows how the indigenous ‘kamp’ agrarian structure underpinned the development of Zonhoven. Operating as a printing plate, the micro-topographical

features of this drainage system were subsequently parasitised by layers of (sub-) urbanisation. (Figure 3a. 1775 Ferraris map; Figure 3b. 1775 Drainage system; Figure 3c. 2012 Urban grain). © Christian Nolf.

The question today is: how (clever) implementation of the decentralised and preventive principles of the new water policy can simultaneously meet and play a role in the dispersed structure of the diffuse city. In other words, can the new systems for the reuse, the infiltration, the retention, and the drainage of rainwater (separated from the sewer) contribute to the legibility, structuring, and densification of the Flemish city. The following case study addresses this question. More particularly, it demonstrates how historical analysis and design exploration can lead to alternatives for the hard engineering solutions that, despite shifting policies, the sector continues to promote.

A sample of diffuse city The rather banal municipality of Zonhoven is representative of the diffused urbanity of Flanders. Located east, in the upstream part of the Demer river basin, it is neither city nor village, but rather something between a bloated allotment and an extensive agglomeration of detached houses. The houses are more or less homogeneously distributed over the territory, but not necessarily well ordered. Zonhoven knew important moments of growth during the coal mining of the twentieth century when it made available cheap land for miners to acquire property. Today, Zonhoven counts 21,000 inhabitants for 40 square kilometres, which is equivalent to an average density of 520 inhabitants per square kilometre, only slightly above the Flemish average.

As a representative sample of the Flemish diffuse city, Zonhoven faces a series of typical issues concerning its urban water management. The most pressing challenge is the drainage of rainwater. As is the case throughout urbanised Flanders, all surface water is collected in a combined sewer piped network. Conceived and dimensioned some time ago, this sewer system is steadily stressed as urban expansion continues. With the accumulation of roof, terrace, and road surface, less water infiltrates in the ground and flows directly into the sewer network. Nowadays, heavy rain equals sewer overflows, leading to urban floods and peak flows of diffusely polluted water all over the territory and, finally, in the receiving river.

To reduce the risk of sewer overflows and resultant peak discharges and flooding downstream, the new water policy’s ‘principle of optimal disconnection’ requires the separate collection and drainage of rainwater (VMM, 1999). To realise this, different approaches are possible. In most Flemish municipalities, the disconnection is envisaged through the creation of a parallel underground network dedicated to rainwater. In Zonhoven, where 75 kilometres of the existing sewer network are still combined, this represents a necessary investment of €50 million. The question that arises addresses the possibility of an alternative solution: in this extensive urban structure with plenty of green spaces, are there less expensive and more ecological solutions to drain and manage the rainwater.

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External input : Ministry of Foreign Affairs, Republic of Turkey Ministry of Culture & Tourism, Republic of Turkey External consultants : Faculty of Architecture, Istanbul Bilgi University, Istanbul, TR Istanbul Metropolitan Municipality

Municipality of Arnavutkรถy Directorate of Planning & Projects

Istanbul Water & Sewerage Authority (ISKI)

Municipality of Arnavutkรถy 51N4E

Asu Aksoy 5th IABR Test Site Curator.

Istanbul Bilgi University, TR

Architecture Workroom Brussels International Architecture Biennale Rotterdam

Istanbul Regional Directorate of Forestry

H +N +S Landscape Architects

Istanbul Food, Agriculture & Livestock Directorate

External consultants : Asli Cicek (Istanbul) Thorsten Schuetze (Water) Sybrand Tjallingii (Water) Peter Smeets (Agriculture) Paul Jorna (Development strategy)

Atelier Istanbul

Ministry of Environment & Urban Planning

External input : Ministry of Infrastructure & the Environment, the Netherlands Ministry of Economic Affairs, Agriculture & Innovation, the Netherlands Ministry of Foreign Affairs / Dutch Consulate, the Netherlands Municipality of Rotterdam, NL

Initiators

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Figure 1. (Top) Constellation scheme of the parties involved in the strategic vision of Atelier Istanbul.

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Figure 2. (Bottom) Istanbul, a rapidly growing megacity. Urban Growth diagram, taken from Burdett, R. (2009) Istanbul: city of intersections. London: Urban Age/ London School of Economics.

productive and is able to curb uncontrolled growth in the water basin. The direct relationship between urban and landscape additionally produces a specific living environment, in which benefits of urban living are coupled to an abundance of open landscape at close proximity. If extrapolated to the scale of Metropolitan Istanbul, this strategy produces an alternative macro-form of the city based on its natural basins structure. In that form, growth could be channelled into a sustainable configuration and put to use to safeguard the resources.

Making City By the middle of this century, the number of people living in the world’s cities will have more than doubled. Cities will produce over 90% of the world’s wealth (IABR, 2012). This global shift urged the 5th edition of the International Architecture Biennial Rotterdam: ‘Making City’ to pose questions about city-making strategies.

How can we address the challenge of making city for such vast numbers? Do we really know how to design and manage cities more effectively? Can the city become a more sustainable environment for continued prosperity, with equal opportunities for billions of urban dwellers? The 5th International Architecture Biennale Rotterdam (IABR) was a call to all stakeholders – administrators, policymakers, politicians, designers, and cities – to start new alliances and take constructive, sustainable action. As part of this edition, Test Site projects were initiated: open-minded, design-driven development trajectories, often spanning several years, always linked to existing urban projects in cities in The Netherlands or abroad. Besides aiming at finding applicable solutions, the ambition was to create the conditions to test new perceptions of planning.

Atelier Istanbul A joint initiative of the Arnavutköy Municipality and the IABR, the Atelier Istanbul was one of the three test sites, next to Rotterdam and Sao Paolo, established in the context of the 5th IABR. Its goal was to develop a Strategic Vision and Action Plan for the Arnavutköy area in northern Istanbul that would recognise and integrate (instead of negate) the forces of social, economic, and urban transformation and the ecological and environmental urgencies (Aksoy, 2012).

The Atelier set out to explore how to make the seemingly irreconcilable logics of urbanisation and resources protection currently work to one another’s benefit instead of competing for land. This initiative developed an effective and operational strategic vision to manage, steer, and guide urban transformation and growth that fed into the agricultural system, which in turn, contributed to the sustainability of the city.

The strategic vision was the result of a design process that reunited several local and international experts who worked with different stakeholders’ priorities

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(Barcalona / Manhattan)

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more density = more output = more protection

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Figure 11. (Top) Productive density: More density = more output = more protection.

Additionally, urban development in high densities make re-use systems more economical to implement.

Figure 12. (Bottom) A very specific living condition: the city enveloping the open landscape.

designated zones for fear of interference with the natural forests. These picnics can find a vast appropriable version in the new forest band marking the edge of the ridge city. Finally, the water basin itself obtains a prominent place in the new parts of the city as a symbolic point of reference. The resulting multifunctional landscape is both productive and attractive.

Since 2012, pilot sites have been studied to test tools regarding time management, property rights management, and cross-authority collaborations.

Unlike a plan, the strategic vision is about the steering of processes. Considering that many municipalities in and around the metropolitan area of Istanbul face similar challenges, it is valuable to see if the same integrated planning principles can be reproduced around other basins and how application of this strategy can result in a sustainable urban configuration for Istanbul.

Istanbul: nightmare or example?

The main ambition of Atelier Istanbul was to shape a new alliance between the city and its resources. The vision proposes an expansion strategy for Istanbul in which urbanisation, agriculture, and eco-systems reinforce one another. The logic that was worked out allows urban development and productive landscapes to contribute to one another, rather than be treated as separate problems.

Whatever technological and spatial expertise is needed, the biggest challenge probably is of an organisational nature in a context of powerful but distinct administration sectors and a robust top-down approach. A crucial target of the whole operation is to foster a new culture on urban development elaborating on the capacity already in place. With the first projects geared towards implementation, a governance structure that can integrate a broad spectrum of fields and be reactive to both local and global concerns seems to slowly gain ground on the traditional top-down planning methods. The coalition of institutions, individuals, and businesses built through the research-bydesign process of Atelier Istanbul has laid the foundation for multidisciplinary projects unique in Turkey. The integrated planning strategy connects short-term interventions on quick-paced urban dynamics with long-term vision required for dealing with the underground, (urban) water systems, ecology, and the effects of climate change. It addresses issues that come into play on different levels of scale. While traditional planning in Metropolises often has a sectorial and an urban focus, breakthrough solutions only can be found in integrated relationships between the city and its surrounding landscape.

The recent announcement of a series of huge infrastructural projects to be parachuted onto the northern area of Istanbul – a third airport, a new city for millions on the coast of the Black Sea, a new canal to mitigate the pressure on The Bosporus, and a new highway connecting all these projects to Europe and Asia, which will cross the Bosporus over a new, third bridge – raises questions

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Figure 4. The banks of the Suzhou River are occupied by motor vehicles and buildings. Source: Photograph by the author.

The present relationship between the river network and urban pedestrian environments As the waterfront demonstrates, rivers can be important components of the urban landscape. The waterfront with its open eyeshot could be the most attractive area in the city. However, it needs to be properly arranged as public space accessible to pedestrians.

In the central areas of Shanghai, there is in general very little relation between the surface water system and walking environments. Whilst it is true that the riverbanks of the Huangpu River have been transformed into a public space provided with pedestrian systems of high accessibility and quality, the Suzhou Creek, as well as a large number of small and medium rivers, still lack attention and clear governance. Motor vehicles and buildings usually occupy these riverbanks (Figure 4). Additionally, due to the requirements of flood control, there is always a big level-difference between embankment and constant water level.

However, the reconstruction of the urban pedestrian system should make full use of the urban water system. The surface water network should function as guidance while carrying on a legible plan layout. On the one hand, we should pay attention to the combination of the waterfront spaces and the overall walking system. The walking path of waterfront spaces should be continuous and various.

As such, it would be suitable for both walking and rest and would meet the needs of a wide range of public activities. On the other hand, we should make the waterfront spaces more accessible by design. We can set up the platform of different elevations, which combine the precious natural resources with urban lives.

The multiple roles of the water system in reconstructing urban pedestrian environments With regard to the present situation of water resources in Shanghai and the current emergence of urban waterlogging phenomena, re-examining the city’s stormwater management in the perspective of WSUD has an important practical significance. If a water sensitive urban design method is applied to repair and improve the small and middle rivers in Shanghai centre area, it can enable the river to play a key role in improving the quality of the urban walking environments.

Water system as ecological regulator in the urban pedestrian environment Urban water systems can play a significant role in regulating the microclimate of the city. The restoration of the urban water systems can help improve natural ventilation, reduce urban heat island effect, alleviate noise pollution, and improve

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Contour line Contour line Major in valleys and plateaus Majorspace spaces in valleys and plateaus Maelbeek Maelbeekcatchment catchment 0 0.5

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Figure 4. (Top) Maelbeek Valley: topographic relief and wide areas in valleys and plateaus.

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Figure 5. (Bottom) Maelbeek Valley: builtup space and ‘intruders’ (interpretation from Studio 011, 2011).

Maelbeek. In particular, the text clearly shows how water played a pivotal role unequivocally manifested in the landscape (Figure 3). Besides that, the account of de Pauw highlights that, under a historical perspective, unthinkable shifts – as for instance the vaulting of the main river of the valley – occur beyond the day-to-day scepticism and inertia to change.

Landform The Maelbeek is a narrow, elongated stream valley generated mainly by quaternary violent water deluges (de Pauw, 1914). The alluvial plain of the Maelbeek dips gently to the north towards the Senne River Valley and in about 7 kilometres changes from an altitude of 70 metres in the South to 20 metres in the North (Figure 4). Towards its end part, in the Northeast, the secondary small Josaphat Valley – formerly called Kattepoel – pours into the Maelbeek Valley. In the most flat parts of the alluvial plain, small parks, public squares, and infrastructural strips are located. This is the case of the ensemble Abbey of La Cambre-Ponds of Ixelles-Place Flagey (Figure 4, detail 1), the ensemble Place Jourdan-Park Leopold-Place Jean-Rey (Figure 4, detail 2), Square Marie-Louise (Figure 4, detail 3), Place St-Josse (Figure 4, detail 4), Place de Heuffalize (Figure 4, detail 5), Park Josaphat with the football fields’ area (Figure 4, detail 6), and the railway line Brussels-Namur (Figure 4, detail 7). The slopes surrounding the valley are generally steep especially in the south and central parts where on the hilltops altitudes range between 70 and 110 metres above sea level. Micro plateaus are located mainly on hilltops and a few more times on the hillside to encircle the valley. They often accommodate representative public buildings, parks, and lavish residential or office neighbourhoods. The most relevant flat spots are the one that at the South East accommodates the Military buildings of the Caserne Lieutenant Général Baron de Witte de Haelen and the Campus of the ULB and VUB universities (Figure 4, detail a; between 90 and 80 metres above sea level), and the one that on the west side accommodates the European Quarter (Figure 4, detail b; between 70 and 60 metres above sea level)16.

Urbanisation In the Maelbeek catchment area, urbanisation is ubiquitous (Figure 5). The area of the Maelbeek watershed represents an extended section of the first urban belt of Brussels that was mainly urbanised from the end of the XVIII/beginning of the XIX century by the ambitious industrial Brussels’s bourgeoisie – also including artisans, merchants, etc. These elites, in order to get out the “frenetic life of the centre” (Heymans, 1998, p.17) – settled on the sides and tops of the hills surrounding the historical centre (see Figure 2)17. That is the reason why the urban tissue of the Maelbeek is mainly composed by the architectural typology

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Floodablespace areas Built-up

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Figure 17. (Top) Maelbeek Valley: built up space and floodable areas.

(Data source: Brussels Environment)

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Figure 18. (Bottom) Maelbeek Valley: groundwater quality. The map presents the data concerning the sole Sables du Bruxellien. Interpretation from Bruxelles Environment (2015b).

the co-production of hydraulic studies – e.g., Quadeau (BE, 2015) – participatory cartography including preliminary plans – e.g., Nouvelles Rivières Urbaines (Bastin et al., 2015b) – and the implementation of pilot projects – Pavillion City Mine(d) (City Mine(d), 2013; Figure 16). Around these initiatives, a new governance concept has been introduced and is under discussion with the regional authorities and some BCR’s municipality. Named Bassin Versant Solidaire, it brings the catchment and both its physiography and social components at the centre28.

Disruptions Flooding. The combined sewage network of the Maelbeek is sensitive to heavy storms and long rainfall events. This is at odds with the fixed capacity of its pipelines. Even now, despite the contribution of the measures implemented in recent times to counteract the risk, about one-sixth of the Maelbeek catchment area is flood-prone29 (Figure 17). The floodable zone largely corresponds to the valley. Besides parks and squares, potential floods concern relatively large urbanized patches. According to the existing climate models for central Belgium (Baguis et al., 2009), in the coming future, the region will have to cope with changing precipitation patterns that may further increase the risk of flood.

Bad water in the underground. In the watershed, groundwater has an average mediocre quality (Figure 18). According to Brussels Environment (BE, 2015b), chemical pollutants (nitrates, pesticides, and the tetrachloroethylene) are abundant in the subsoil and the Eocene formation sable du Bruxellien in particular. The out-dated sewage network – that in some parts is more than 100 years old – leaks sewer water infiltrating the permeable layers of the soil to reach the ground water table. The renovation of the sewage network is ongoing but the operation – extremely costly – will take a long time30.

3. The neighbourhood as testing case for integrated watershed configurations The identification of the appropriate spatial scale at which the spatial arrangement of water in Brussels should be investigated is not apparent. On the one side, if BCR is not a hydrological unit per se, the Brussels’ techno-scientific arrangement of water has a strong regional connotation. Levers and valves to control water provision and disposal metabolise water in and out of the region – and hence, in turn, territorialise the same regional borders. On the other side, both biophysical laws of water and the multifarious mediations operated by human society on water make it difficult to catch the phenomenology of this flow at a glance31.

Whilst the regional scale is a fact, what it is argued here is that, in order to identify the spatial scale of design oriented exploration on the water arrangements of Brussels inspired by IWM, both the biophysical behaviour of water and the physical materials of the urban-milieu should be taken as determinants.

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In the event that rain falling on the Maelbeek was moved as far as possible above ground, surface water would fill the overall urban landscape. Discreet open-air water lines would permeate the slopes of Quartier Vijevers Van Elsene and Quartier Flagey-Malibran. Streams would equally follow streets and cross inside of building blocks. Alongside the waterlines, temporary spaces for water – small-sized, inside the building blocks, and medium-sized, in the public space – would occur.

Together with the wide pond of Étangs d’Ixelles, they would merge ‘to wet’ the urban landscape.

Alessandra Marcon and Marie Pire

Towards New Urban ‘Hydrographies’

From pipeline drainage networks to new urban ‘hydrographies’ In the last few decades, water has become increasingly recognised as a bearer of urban quality, and water management boards are more open to new approaches integrating the global water cycle (Mahaut et al., 2011). On the one side, proximity to water is seen as a mean of beatification to increase the positional allowance of properties and new urban expansions. On the other side, as the existing urban fabric is increasingly affected by inundations and other water dysfunctions, cities are searching for more space for water (Klijn, 2013) to satisfy the requirements of most recent policies (e.g., in Europe, the EU Flood Directive and the Water Framework Directive)1. This increasing interest towards water issues is often associated with the theme of resilience: the ability of a system (in this case the urban fabric) to adapt to changing conditions while absorbing disturbance, like, in the case of water, its excess and lack, while still maintaining basic functions and structures. In this way, green spaces and parks have been reinterpreted by urban designers as spaces capable of accommodating water temporarily before releasing it downstream or infiltrating it into the ground. At the same time, these water sensitive devices are often multifunctional, allowing the integration of different types of programmes (leisure, recreation, or landscape ‘installations’) and increasing biodiversity.

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These interventions are relatively simple while keeping open areas free from urbanisation, but become more complex when affecting existing urban fabric.

In this second case, sometimes the chosen option is river retrofitting, since in many cases the urbanisation processes have gone along with the abolition of the former hydrographic system in favour of underground combined sewage systems collecting stormwater and wastewater at once. River retrofitting means the reopening of buried streams and rivers to recreate the ancient natural environment.

This is the counter strategy recently deployed to reintroduce the ‘original’ hydrography in the urban landscape with 160 projects documented worldwide (Brun, 2014). The retrofitting operations are reliable when the original traces run trough open spaces and public properties, but they meet some constraints specifically in the need for separation of stormwater from the sewage, high costs of intervention, emerging social awareness, and need for high technical knowledge (Adam et al., 2007). More often, the result is a discontinuous system of open-air segments and pipes, where the conflicts of use are superposed (Scherrer, 2004).

However, other strategies to bring back water networks on the surface are emerging (Mahaut, 2009). These strategies seem to accept that urban development is an irreversible fact and a given condition that asks the population to identify solutions and approaches that work. These strategies internalise the ecological principle of working from the very source of water. The attempt is making water visible from the point it falls, all along its path, down to the last sink point. Roofs, gardens, parking lots, squares, etc. become new occasions to re-design the urban space and, at the same time, shape ‘new hydrographies’.

Accordingly, new trajectories can be designed all across the city landscape down to the bottom of the valley. The idea of New Urban Hydrographies arises to follow a multivariate strategy: making water visible for increasing public awareness; introducing multifunctional water storage facilities to enhancing public investments; implementing sorts of urban backbone following water path and structuring public spaces; integrating water inundation areas with recreational uses; moderating the effects of weather-related events, slowing-down rainwater run-off; increasing bio-diversity and environmental continuity within the urban fabric.

Brussels’ new hydrography: from the lot to the plot scale In highly impermeable areas, where natural river systems and aquifers have been strongly perturbed over the centuries, inundations are often due to excess of runoff caused by strong rainstorms and the consequent pipeline networks’ overflows, rather than by river overflow. This for example, is the case of the urbanised territory of Brussels-Capital Region (RBC-PP 2008). In order to give concrete answers regarding flood events, in 2008 the Brussels regional authorities adopted

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Impermeable Surface water Permeable Slope

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Diversity typifies both the soil permeability of the Brussels Capital Region (top left) as well as with a different grain, that of the Maelbeek catchment (bottom left). On this given condition, urbanization has designed geography of paved and unpaved areas (right). As one condition adds to the other, the resulting socio-natural arrangement shows a greater diversity, directly influencing the behaviour of water.

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What if2016 the integrated water arrangement of the Maelbeek After Valley would intertwine with the spatial heterogeneity?

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Maelbeek catchment Brussels-Charleroi Canal Stream / river Pond Maelbeek / wetland catchment Sewage collector / buriedCanal stream / buried river Brussels-Charleroi NorthStream treatment plant / river Decentralized water arrangements Pond / wetland Maelbeek catchment Sewage collector / buried stream / buried river Brussels-Charleroi Canal North treatment plant Short pathwaysStream of water could take as many different routes in / river Decentralized water arrangements the water sensitive arrangement intertwined with the spatial Pond wetland urban landscape. Each urban pattern heterogeneity of the /Maelbeek would offer specific conditions for storage and processing of water Sewage collector / buried stream / buried river onsite. The close-grained diversity of uses would set off the mutual support of the different entities.plant For example, the shortage of room North treatment for water in a cluster of offices could be outweighed by the front Water-detention pond close by. Regardless of the gardens of a residential neighbourhood differences, all the patterns could contribute to supply the ‘courbes d’eau’, namely streams flowing gently in those streets running alongside the catchment’s contour lines.

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Marta De Marchi

Water Management in the Light of Social Topography

Social Topographies and water management The New Urban Question of today seems to involve aspects that until now we considered as separated problems. These issues include the economic crisis in western and Asian countries, the environmental question, and the growing social and spatial injustice inside cities and metropolitan areas (Secchi, 2010).

Over the last few years, several scholars recognised an interconnection between these elements and the need to consider these issues while designing new urban configurations and infrastructure (Donzelot, 2009; Secchi, 2014).

Even if in some European countries the economy seems to be on the mend, economic crisis brought to light deeper differences between social groups (OECD, 2008). During the past few years, we saw a reduction of the middle class and the increase of the gap between wealthier and poorest classes. The trend suggests that this gap could grow in the future (Eurostat, 2014). In the urban context, this gap increases social segregation (Atkinson, 2008) and reveals a strong “social topography� as an expression of a spatial distribution of different social groups and their respective urban practices and behaviours (Secchi, 2013).

In addition to the economic crisis, the environmental question is revealing its consequences at the social level. Pollution of air, water, and soil, resources scarcity, and climate change are affecting the situation of those populations

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that are already in difficult social conditions. This is very clear when we refer to water. The consequences of phenomena like floods and droughts, for example, are even stronger along riverbanks or in former floodplains, where powerless social groups often settle (Robertson, 2012). Although self-evident in many situations of the Global South, the burden of the environmental concerns on powerless social groups is an issue in wealthy areas of the Western countries. These problems are compounded by the changing climate change patterns. According to the forecasts, the continental climate of Central Europe is becoming more similar to the Mediterranean climate, with droughts during summer and extreme rainfalls during autumn and winter, making existing water drainage systems inefficient (European Environment Agency, 2012). Hydraulic risk does not only affect physical accessibility, mobility, and the economic activities, it also involves social dynamics that should not be considered apart. Today, in western cities, communities increasingly ask for answers to water related problems such as inadequate water supply services, floods, or water contamination. In particular, both in Europe and in the USA, the population has assisted the recent birth of associations and very active citizens groups. In New York City, for example, since 2011, the Water Trail Association involves citizens in tours along the river Hudson, recently affected by chemical pollution. The purpose is collecting water samples to monitor the state of chemical composition. An on-line platform shares results periodically with the citizenship (New York City Water Trail Association, 2015). In Brussels, the Etats Généreaux de l’Eau is a platform of citizens and experts that promote activities and campaigns with the aim to sensitise the city regarding water related urban problems, to promote solidarity between citizens, and to support studies and research on alternative water strategies (Etats Généreaux de l’Eau à Bruxelles, 2014). One of the reasons that bottom-up experiences like these are rising in different metropolitan contexts, is the fact that local administrations responsible for the public water system are facing serious economic constraints that often do not permit the dysfunctions (Davey, 2011).

It turns out that the New Urban Question challenges conventional urban water management. In the last ten years, researchers found a gradual shift from a traditional input/output approach to a more integrative water cycle management that worked with small scale and preferred the integration of decentralised solutions (Coombes & Mitchell, 2006). The advantages of integrating the centralised system with decentralised water devices are several. First, according to the changing climate patterns, it permits distribution of increasing amounts of rainwater in a more extended area, rather than concentrating it downstream.

Secondly, the urban surface is used to give room for water. As a result storm water runoff slows down and the amount of water reaching the treatment plants reduces considerably, reducing also the cost of the treatment. Moreover, the water upstream can be collected and reused for urban and domestic purposes (Taptiklis, 2015). Thirdly, the integration of decentralised systems can contribute

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Figure 1. The inexorable continuity of land subdivision: le Leopold Quartier project as first layout for the urban Eastern Brussels expansion.

Public spaces and buildings 1. Beltway 2. Square Orban 3. Rue de la Loi 4. Etterbeek road 5. Crown Avenue 6. Crown avenue bridging rue Gray in the Maelbeek valley 7. Luxembourg Square 8. Public Staircase of the « Garden of the Maelbeek » 9. Rue Belliard 10. Abbey of La Cambre 11. Place Saint-Josse 12. Place Jourdan, Etterbeek 13. Place Flagey, Ixelles 14. Place Hauwaert 15. Berlaymont (European Commission) 16. Consilium/Residence Palace 17. Justus Lipsius 18. Rond-Point Schuman 19. Charlemagne building 20. Lex buildings 21. Residence Palace 22. European Parliament Places and areas A. Leopold Quarter B. Royal Park C. Maelbeek Valley D. Linthout Plateau E. Leopold Park F. Railway line to Namur G. Northeast Extension H. Quartier des Etangs d’Ixelles I. Abbey of La Cambre J. Park Cinquentenaire K. Bois de La Cambre L. Leghait’s projects M. Groupe Alpha projects N. Social Housing Complex in the Maelbeek valley O. Highway E40 to Liège

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Figure 5. (Right) The valley structuring urbanisation: from the chain of ponds to the chain of civic centres. The urban regeneration by the municipalities.

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Sybrand Tjallingii

Epilogue: Designers’ Dreams and Urban Water

To urban designers water can be a source of inspiration. This book is a good illustration that focuses on the water world of Brussels. It presents contributions about the role designers play in shaping water use and visible water in urban environments in different parts of the world with different stages and forms of urbanisation. At first sight, the plans and projects discussed here are very different; yet, they share a concern with the role of rain. This is not self-evident for urban designers. What is so special about this focus? To throw more light on the special character of this approach, it is interesting to compare it with the more traditional ways designers are looking at water that may be described as dooms or dreams.

Dooms often dominate the debate about water, framing it as a safety issue.

In 2004, water was the leading theme of the International Architecture Biennale of Rotterdam. The curator, landscape architect Adriaan Geuze, chose The Flood as the title of that year’s exhibition. It demonstrated the tendency to focus on the role of water in climate change and sea level rise. In An Inconvenient Truth, Al Gore presents the images of big floods to stress the urgency of the issue. In Bangladesh and some other deltas of the world, the situation is dramatic. It is urgent to prevent floods and the media love to frame the story of water in that way. Doom thinking is drama and drama cries for heroes. Designers can be these heroes if they build landmark dams, storm surge barriers, and other big projects.

However, water is more than great building projects.

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Contributors Marco Ranzato, editor, is a researcher at the Faculty of Architecture La Cambre Horta of the Université Libre de Bruxelles and co-director of Latitude Platform for Urban Research and Design. His research focuses on expanded understanding of ecological design, processes of horizontal urbanization, as well as on coproduction, focusing in particular on co-production of water, energy, and waste services and co-design.

Olivia Adamska graduated in architecture at the Faculty of Architecture La Cambre-Horta of the Université libre de Bruxelles. She presently works at Bruxelles Environnement, the institution responsible for the Environment in the Brussels Capital Region.

Andrea Aragone is an urbanist. In 2015, he graduated from TU Delft with a master’s thesis on the socio-spatial potential of the public realm and the processes that occur between different communities in the Matonge district of Bruxelles. As a member of Latitude Platform for Urban Research and Design since 2012, he has worked on the relationship between water dynamics and urban transformations. In 2016, he worked at drafting the regional master plan for the cities of Durrës, Shijak, and Vorë in Albania as an in loco expert for the environmental assets.

Ilaria Boniburini is an architect and scholar with experience in public spaces, the right to the city, and African urbanism. After working as Senior Lecturer in urban design at the University of Rwanda she joined the University of the Witwatersrand, as a post-doc fellow, in September 2015.

Andrea Bortolotti is an architect and currently a PhD candidate at Université Libre de Bruxelles, Faculté d’Architecture La Cambre-Horta in Brussels. His main research topics concern urban metabolism and the relationship between urban design and ecology. Since 2011, he has been a member of Latitude Platform for Urban Research and Design.

Pauline Cabrit graduated in landscape architecture at the Ecole Nationale d’Architecture et de Paysage de Bordeaux. She is currently part of the team of the Charleroi Bouwmeester, an independent organisation providing planning design support to the local municipality of Charleroi.

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Simone Conz obtained a bachelor’s degree in Urban Planning from IUAV University of Venice. He started working with Latitude Platform for Urban Research and Design in Brussels during his time at KU Leuven as a visiting student. He has then obtained a master’s degree from Politecnico di Torino with a thesis based on the Latitude research project “Reducing Boundaries”.

Siyu Liu studied architecture conservation at Tongji University in Shanghai. She is currently pursuing a master’s degree in Landscape Architecture at Harvard Graduate School of Design. Concerned with the interaction between the living environment, preservation, and social problems, Siyu is interested in how designers can engage with vernacular design in developing countries.

Marta De Marchi is a landscape architect and a PhD candidate in Urbanism at IUAV University of Venice. Her field of research concerns the Sustainable Food Planning and the food related territorial transformations. Since 2012, she has been member of Latitude Platform for Urban Research and Design.

Bruno De Meulder is Professor of Urbanism at the University of Leuven (Belgium) where he is program director of MAHS/MaUSP and head of RUA (OSA), the Research Group Urbanism and Architecture. He combines the historical investigation of urbanism with urban design explorations in dynamic contexts of change.

Catalina Codruta Dobre is a PhD candidate at the Université Libre de Bruxelles.

Her on-going thesis investigates the transition of urban water systems towards a Water Sensitive City. She is actively involved in the organisation of design workshops regarding the implementation of sustainable water management practices in urban areas. In 2015, she received the Green Talent Award offered by the German Federal Ministry of Education and Research for her interdisciplinary research on sustainability.

Bianca Fanta is a freelance landscape architect and has worked with EspacesMobilités office in Brussels since January 2016. She has a master’s degree in landscape architecture from the University of Liège (Gembloux Agro-Bio Tech) and a bachelor’s degree in Landscape Engineering from the University of Agricultural Sciences and Veterinary Medicine in Cluj-Napoca, Romania.

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Martina Gentili is a PhD candidate at the Gran Sasso Science Institute in L’Aquila and a guest researcher at the OTB department of TU Delft. She works on the relationship between planning, housing, and illicit practices. As a member of Latitude Platform for Urban Research and Design, she is working on “Ilot d’Eau,” a co-design project that explores bottom-up solutions for water management in dense urban areas.

Roberto Genna is an architect and urbanist working as a freelancer with the Belgian office BUUR since 2013. He studied architecture at IUAV University of Venice. After graduating in 2012 he started working with Latitude Platform for Urban Research and Design, exploring issues of urban and territorial development in relation to hydraulic risks, economic and social issues.

David Hedgecock is Professor of Urban and Regional Planning at Curtin University, Western Australia. He is internationally recognised for his work on the initiation and implementation of the concept of water sensitive urban design. He was instrumental in the development of water sensitive policy and guidelines for the State of Western Australia.

Sotiria Kornaropoulou is an architect at 51N4E since 2006, where she has been busy with architectural and urban projects in Belgium, the Netherlands, Albania, and Turkey. She has also prepared and presented multiple publications, exhibitions, and lectures at home and abroad. In 2013-14, she led two thesis studios for the Urbanism & Strategic Planning master program of KU Leuven.

Géry Leloutre is an architect and urban designer in Brussels (Karbon) and is a teacher on the Faculty of Architecture of the Université Libre de Bruxelles (ULB).

He is a PhD candidate in Urbanism at ULB and IUAV University of Venice, and at the same time he is co-coordinating doctoral research in DR Congo (Kinshasa).

Alessandra Marcon is an architect and urbanist working at Obras office of urbanism and architecture in Paris. She studied at IUAV University of Venice and Marne-la-Vallée School of cities and territories in Paris. Her field of research concerns water issues in European fragile landscapes. She has been a member of Latitude Platform for Urban Research and Design since 2012.

Luisa Moretto is Associate Professor at the Faculty of Architecture of the Université Libre de Bruxelles (ULB). She has a background in architecture and holds a PhD in Analysis and Governance of Sustainable Development from the University of Venice.

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Mike Mouritz (Dr.) is an executive at the City of Canning in Perth, Western Australia, where he works on urban renewal projects. He is on the board of the Cooperative Research Centre for Water Sensitive Cities, which fosters research and development of transitions to more water sensitive practices.

Christian Nolf is Lecturer in the Department of Urban Planning and Design in XJTLU (Xi’an Jiaotong-Liverpool University) in Suzhou, China, where he co-directs the Research Institute of Urbanization and coordinates the MSc in Urban Design.

He holds a PhD in Engineering, Science, & Architecture (KULeuven & UHasselt, 2013), has been a tutor in the European Masters in Urbanism, and a lecturer in Architecture at Antwerp University.

Marie Pire is a landscape designer. Graduate from the National School of Landscape of Versailles, she is dedicated to the subject of urban waters, specifically rainwater. Having specialized in urban hydrology, she conceives “Floodable towns” and “Fertile cities” where the presence and the weaving of the water generates different ambiences, vast biodiversity, and real identities.

Dirk Sijmons was one of the founders of H+N+S Landscape-architects in 1990.

He received the Rotterdam-Maaskant award in 2002. English book publications include: Landscape (1998), Greetings from Europe (2008), Landscape and Energy (2014), and Moved Movement (2015). Sijmons was appointed first State Landscape Architect of the Netherlands (2004-2008). Recently, he was the curator of IABR-2014 Urban-by-Nature. Until 2015, he was Professor of Landscape Architecture at TU Delft.

Maëlle Thueux is a landscape architect. She approaches and questions the issues of large-scale urban developments within Perspective, a Brussels planning office.

Involved in citizen projects of allotment and urban compost, she also experiments in small-scale urbanism through the Transition Movement.

Sun Tongyu holds a PhD from the Tongji University of Shanghai. He is currently Vice Dean at CAUP Tongji University, leader Professor at Institute of Urban space, honorary Professor of Intelligent Urbanization at Co-creation Center for High Density Region, and he is also the director of design division four at the Tongji Design Institute. His main research field is urban design and architecture design.

Sybrand Tjallingii is a Dutch urban planner with a background in landscape ecology. His PhD Thesis Ecological Conditions (TU Delft 1996) analysed ecological strategies in urban planning. He retired as an Associate Professor in 2006.

Presently, he works in teaching, research, and consultancy. Water is a central theme in his work.

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Jaap van der Salm studied Landscape Architecture at Wageningen University and has worked as a landscape architect for H+N+S since 2010. There he focuses mainly on large-scale water related national and international projects. In his projects, Jaap combines solutions for flood safety with ecological, recreational, and urban development.

Xiaoyu Wu majored in Architecture at Tongji University, Shanghai, focusing on Energy & Thermodynamic Architecture. Wu worked as an intern at Kengo Kuma & Associates (Tokyo) and Atelier L+ (Shanghai). She is currently finishing a MSArch double-degree at Rensselaer Polytechnic Institute, US. Yixin Xu has a bachelor’s degree in Landscape Architecture from Tongji University in Shanghai and a MSArch from Pratt Institute Graduate School of Architecture and Urban Design in the United States.

Zhao Yang majored in Landscape Architecture at Tongji University in Shanghai in 2015. He then obtained a master’s degree in Landscape Planning from Tongji University. From 2016, he started a dual master’s degree in urban design at the Technical University of Berlin.

Giambattista Zaccariotto is an Associate Professor at AHO Oslo, consultant at Asplan Viak, Design and Research Foundation Norway, and visiting professor at EMU IUAV. He studied at IUAV University of Venice and TU Delft where he also received a European PhD in Urbanism in 2010. He is co-editor of the books Scarcity in Excess, The Built Environment and the Economic Crisis in Iceland (2014), and Landscapes of Water (2008).

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