REGENeration: Spatial Solutions for Rainwater Storage and Reuse in the Urban Environment by Mary Brown

MARY BROWN MCGREGOR POLITECNICO DI MILANO FIELD FACTORS

REGENERATION OF URBAN WATER SYSTEMS SPATIAL SOLUTIONS FOR RAINWATER STORAGE AND REUSE IN THE URBAN ENVIRONMENT by MARY BROWN MCGREGOR [10652374]

The information in this document has been submitted as a Sustainable Architecture and Landscape Design Thesis to the School of Architecture Urban Planning Construction Engineering at Politecnico di Milano.

ACKNOWLEDGEMENTS I would first like to thank my supervisor, Professoressa Sara Protasoni, whose feedback was key in developing the design to support my research methodology. I would like to acknowledge my internship at Field Factors, as knowledge and research used to develop this thesis came from an on-going project of theirs. I'd like to thank the Field Factors team for being so inviting and offering their support and technical knowledge of rainwater management technology. I would particularly like to thank my supervisor, Wilrik Kok, Chief of Commerce at Field Factors, who invested thorough amounts of time and knowledge to this project. In addition, I would like to thank my friend and classmate, Jiani Huang, for her continuous encouragement.

This document has been developed under the supervision of Prof. Sara Protasoni and co-supervison of Wilrik Kok, as part of a Bluebloqs Circular Water System research project for Field Factors from October 2020 to June 2021.

ABSTRACT EN Today the world faces major global challenges such as climate change, population growth, urbanization, and resource depletion. These issues are most prevalent in our urban environment. According to OECD, by 2050, 86% of the world’s population will be living in urban areas. This means cities are not only challenged to renew and expand for the increase of users, but also to manage and provide certain resources at risk of depletion - water being one to recognize. Major cities are already facing water stress and the demand for water is projected to increase 55% by 2050. A livable city must function in providing its inhabitants with secure food and drinking water production, clean air, social and economic welfare, and health and happiness, which are all dependent on healthy urban water systems. The challenge is not to expand the current centralized urban drainage and supply system, for this is labor intensive and expensive, but to regenerate the existing system to a nature-based, scalable solution of a decentralized model for water supply and discharge. Regeneration is the act of improving a place or system, especially by making it more active or successful. Although the word comes from the Latin verb, regenerāre; the Dutch word ‘regen’, which means rain, gives the support for the following research and design proposal regarding the regeneration of linear to circular urban water systems applied by spatial interventions within the city center of Nieuwegein, a growth-city in the Netherlands. The aim of this thesis is to identify the current challenges to the urban water system, introduce circular water management concepts, outline regenerative design principles and apply them to an existing real estate development project, as a case study. The project site will act as a demonstration for future residential and urban development projects to be designed with the emphasis on blue-green infrastructures. The importance of blue-green infrastructure will be addressed in the utilisation of both the vertical and horizontal planes, with the support of a three-dimensional, decentralised water system. These concepts and application will lead to the effective and sustainable design in developing future climate resilient and adaptive cities.

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

IT Oggi il mondo deve affrontare le principali sfide globali come il cambiamento climatico, la crescita della popolazione, l'urbanizzazione e l'esaurimento delle risorse. Questi problemi sono più diffusi nel nostro ambiente urbano. Secondo l'OCSE, entro il 2050, l'86% della popolazione mondiale vivrà in aree urbane. Ciò significa che le città non sono solo sfidate a rinnovarsi ed espandersi per aumentare gli utenti, ma anche a gestire e fornire alcune risorse a rischio di esaurimento: l'acqua è una cosa da riconoscere. Le grandi città stanno già affrontando lo stress idrico e si prevede che la domanda di acqua aumenterà del 55% entro il 2050. Una città vivibile deve funzionare nel fornire ai suoi abitanti cibo sicuro e produzione di acqua potabile, aria pulita, benessere sociale ed economico, salute e felicità, che dipendono tutti da sistemi idrici urbani sani. La sfida non è espandere l'attuale sistema di drenaggio e approvvigionamento urbano centralizzato, poiché questo è laborioso e costoso, ma rigenerare il sistema esistente in una soluzione scalabile e basata sulla natura di un modello decentralizzato per l'approvvigionamento idrico e lo scarico. La rigenerazione è l'atto di migliorare un luogo o un sistema, soprattutto rendendolo più attivo o di successo. Sebbene la parola derivi dal verbo latino, rigenerāre; la parola olandese "regen", che significa pioggia, fornisce il supporto per la seguente proposta di ricerca e progettazione riguardante la rigenerazione di sistemi idrici urbani da lineari a circolari applicati da interventi spaziali all'interno del centro della città di Nieuwegein, una città in crescita nei Paesi Bassi. Lo scopo di questa tesi è identificare le attuali sfide al sistema idrico urbano, introdurre concetti di gestione dell'acqua circolare, delineare principi di progettazione rigenerativa e applicarli a un progetto di sviluppo immobiliare esistente, come caso di studio. Il sito del progetto fungerà da dimostrazione per futuri progetti di sviluppo residenziale e urbano da progettare con l'accento sulle infrastrutture blu-verdi. L'importanza dell'infrastruttura blu-verde sarà affrontata nell'utilizzo del piano verticale e orizzontale, con il supporto di un sistema idrico tridimensionale e decentralizzato. Questi concetti e applicazioni porteranno alla progettazione efficace e sostenibile nello sviluppo di città future resilienti al clima e adattive.

ABSTRACT

TABLE OF CONTENTS

INTRODUCTION

APPROACH

URBAN WATER CHALLENGE

INSIDE-OUT

1.1 Prologue

2.1 S to XL

1.1.1 Global Water Crisis

2.1.1 Scaling Methodology

1.1.2 History of Urban Water Systems

2.2 Case Study

1.1.3 Global and Local Efforts

2.2.1 Project Area: City West

1.2 Urban Water Concept

2.2.2 City Goals and Infrastructure

1.3 Thesis Outline

2.2.3 Satellite City 2.2.4 The Netherlands

IMPACT

100

FUTURE RESILIENT CITIES 5.1 Regenerative Resiliency 5.1.1 Climate Resilent Cities 5.1.2 Call to Action 5.2 Conclusion 5.2.1 Summary 5.2.2 Regenerative Design Guidelines 5.3 Upscale and Impact 5.3.1 Network Transformation 5.3.2 Future Resiliency 6

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

REFERENCES

106

STRATEGY

APPLICATION

REGENERATIVE DESIGN

DESIGN PROPOSAL

3.1 Blue-Green Infrastructure

4.1 Design Strategy

3.2 Regenerative Design 3.2.1 Principles 3.3 Design Criteria 3.3.1 Context

4.1.1 Context 4.1.2 Adaptability 4.1.3 Utilisation 4.2 Proposal

3.3.2 Adaptability

4.2.1 Design

3.3.3 Utilisation

4.2.2 Goals and Modifications 4.2.3 Masterplan: City West 4.2.4 Sections 4.2.5 Perspectives

01 URBAN WATER CHALLENGE

1.1 PROLOGUE

By 2030 demand for water is expected to increase, while there will be a 40% global shortfall between the demand and available supply. Water is the most precious and critical resource on earth. The water crisis is one of the top five global risks. Climate change, population growth, urbanisation, and resource depletion are the major challenges to the global water cycle, and are most prevalent in our cities. One in four large cities are already facing water stress, putting pressure on the existing urban water supply and infrastructure. The urban water challenges relate to the lack of access to safe water and sanitation for cities, as well as protection from an increase of water-related disasters such as floods and droughts (“Water and Cities” n.d.). Climate change is predicted to cause significant changes in precipitation and temperature patterns, which in turn will affect the availability of water. While population growth and urbanization will lead to an increase in fresh water consumption,

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

the demand will struggle to be satisfied by locally available water sources with the current infrastructure and lack of treated wastewater. The existing infrastructure is aging and deteriorating. Most cities, worldwide, have neglected the maintenance to the water storage, treatment, and distribution systems. The cost in rehabilitation of water infrastructure systems is increasing as they continue to deteriorate. In order to handle these challenges to our urban water cycle, there must be a shift in the management of the urban water system. Interventions on the whole of the urban water cycle must occur. This means reevaluating use and reuse of storm and wastewater and applying nature-based solutions for treatment and storage for future purpose. HISTORY OF URBAN WATER SYSTEMS In examining ancient urban drainage systems, similar techniques of wastewater discharge and stormwater runoff control and reuse are recognized. Most developed from the ancient civilizations’ perspective of urban runoff as a nuisance flooding concern, waste conveyor, and a vital natural resource (Burian and Edwards 2002). When the Roman Empire began to develop urban drainage technology, they expanded from the existing Etruscan built sewers and paved streets, implementing curbs and gutters to direct surface runoff to rock-lined open drainage channels (Hill 1984). The Romans also incorporated rainwater collection techniques within their drainage system, storing urban stormwater runoff for local use and collecting the rainfall on rooftops into a cistern located in the interior of the house (Hodge 1992). They were able to produce one of the earliest examples of an established urban water cycle, through their linkage of urban water supply and drainage by way of aqueduct overflow into sewers. This urban water cycle would become common in western civilizations in the late 19th century with the large-scale construction of piped-in water supplies and distribution sewer systems (Burian and Edwards 2002). City population reduction led to the deterioration of drainage services. During the Dark Ages, there was little concern for individual hygiene, let alone a community’s. This meant, many now open ditch sewage systems, were also used as trash receptacles and human feces disposal. During the Middle Ages in cities like Paris and London, population expansion made the issue of human feces disposal too large to ignore. In general, the ruling class and nobility did not concern themselves with the sewage of the masses, and so urban drainage became privatized owners to, this led to illegal dumping which in turn caused problems for urban drainage systems. Although local acts were passed to address these issues, neglect for the urban drainage system lasted throughout the middle ages. Development of modern urban drainage practices began during the 19th century, to address disease outbreaks, while utilizing technological advances in engineering and construction found from American continents in the 18th century. At this time, most sewers were designed exclusively for stormwater drainage and wastewater was accumulated in privy vaults and cesspools until transported later to a

suitable disposal location. The public perspective changes from a neglectful attitude to a vital public works system (Burian and Edwards 2002). The design and planning of urban drainage systems also changed in the nineteenth century, from a trial-and-error process to numerical engineering standards. The water management model of today can be understood as centralized. Until the late 1990s, urban water supply was controlled by the public sphere and by municipalities. Recently, water services have become marketized and privatized, giving way to changes in the control of the flows of water (Gandy 2004). Water governance is an important aspect of the function of the urban water cycle. Its role on centralized systems determines where and how supply and discharge flow. The benefits of the centralized urban water system have been proven in regards to providing reliable water supplies, flood control, food production and hydroelectricity generation. However, with more developments and environmental changes, their disadvantages in cost and inefficient supply and discharge times and amounts are beginning to outweigh their original benefit. GLOBAL AND LOCAL EFFORTS The global water cycle major challenges, as stated before are climate change, population growth, urbanisation, and resource depletion. There is pressure on the existing urban water supply and infrastructure because of these challenges. Urban Water Challenges: Shift in Rainfall Patterns

Instable Groundwater Levels

Temperature Rise (increase of drought)

Aged Infrastructure

Increase in High Quality Demand

Negative Impact on Supply and Quality

INTRODUCTION

But with challenges, come solutions. It is valuable to recognise the efforts to combat these water cycle challenges at both a global and local scale.

UN SUSTAINABLE GOALS The initiative of the Sustainable Development Goals set by the United Nations is Goal 6: Ensure access to water and sanitation for all. In the most recent Conference for the UNFCCC (United Nations Framework Convention on Climate Change), the unifying agenda was focused around climate adaptation measures related to water. During the COP25, which occurred in December of 2019, it was argued that climate-resilient water management should be flexible and durable, and something to regard for all current and developing cities.

LEED CERTIFICATION LEED (Leadership in Energy and Environmental Design) is one of the most widely used green building and rating systems in the world. LEED provides a framework for healthy, highly efficient, and costsaving green buildings and other urban development projects. Within the rating system, are credits given for water efficiency in design. New buildings and development projects can earn these credits through indoor and outdoor water reuse and reduction.

ARUP RESEARCH AND GUIDANCE ARUP is a global advisory, design, planning and engineering firm for every aspect of the built environment. The company has published various reports on innovative water management, designing with water, and climate-resiliency within the urban water sector. Considering the research of this thesis and the case study it involves is located within the Netherlands, the local solutions to the urban water challenge that are recognized, is from a Dutch, EIT Climate-KIC supported start-up, Field Factors.

FIELD FACTORS BLUEBLOQS The Dutch start-up developed Bluebloqs, a technology that works by locally collecting, treating and storing stormwater treatment in an innovative way through use of the subsoil. They design and build nature-based solutions for decentralised water management in cities.

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

INTRODUCTION

1.2 URBAN WATER CONCEPT

URBAN WATER SYSTEMS There is a need to upgrade the traditional urban network for water supply and discharge. The transformation from a fixed, centralised model to an adaptable, decentralised model is the result of the new urban water network. SEPARATED FLOWS The separation of water flows - stormwater, grey water and black water, will occur at the local scale, allowing production of water from local resources and of different qualities to meet the local demand.

CURRENT FLOW SYSTEM

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

FROM LINEAR... Since the 19th century, centralised water supply and drainage systems have become fundamental to urban development. This model has led to a fixed, one-size-fit-all approach in which stormwater discharge through the sewer is typically combined with wastewater. The supplied water is then used for urban application regardless of its quality.

TO CIRCULAR This is to be done through a flexible and decentralised model. The increased pavement areas can be used as a catchment area to collect rainwater run-off. Collected water is treated and stored locally through small scale water systems, reducing discharge to the municipal network. The stored water is used to meet the local water demand. These small-scale water systems can be implemented in future development projects to create more climate resilient cities.

FUTURE FLOW SYSTEM

INTRODUCTION

VERTICAL AND 3D MODEL The decentralised and flexible model proposed in the future urban water system, is one that utilises its implementation space in a vertical and three-dimensional technique. Through the use of retention and treatment on the ground plane and storage in the subsoil, this model is able to facilitate the integration of blue and green infrastructure. (Further explanation of blue-green infrastructure can be found in Ch. 3 Strategy).

Collection

Retention

Treatment

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

Use

Storage

INTRODUCTION

5 STEP SYSTEM The vertical system relies on 5 steps: 1. Collection - via drains or gutters 2. Retention - in ponds, groundwater, or surface water 3. Treatment - with biofilter 4. Seasonal Storage - in subsoil 5. Use - ie. irrigation, play water

Collection

Retention

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

Treatment

Use

stable groundwater levels

Storage INTRODUCTION

1.3 THESIS OUTLINE

INTRODUCTION

APPROACH

STRATEGY

APPLICATION

IMPACT

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

The purpose of the introduction is to present the challenges of the current urban water system and to introduce the future solutions for the transformation of a more regenerative, blue-green infrastructure focused water system at the urban level.

The Approach will take the urban water concept outlined in the introduction and apply it to a Case Study through the inside-out approach; the scaling method from S to XXL scale. This chapter will introduce the project area and its relevant analysis.

The Strategy will further explain blue-green infrastructure and outline the principles of regenerative design. The principles and concepts defined will then be translated to design criteria that is to be applied to the project area introduced in the Approach.

In the Application, the design criteria described in the Strategy will be translated to a design strategy applicable to the project area introduced in the Approach. Through the design strategy, a preliminary design is developed. The application of the urban water system is contextualised and showcased in the design proposal presented in this chapter.

The Impact will provide insight on the impact regenerative design has for creating climate resilient cities. The evolution from the sustainable design theory to regenerative design will be proposed. This chapter contains a thesis summary and call to action for future of design in architecture, landscape architecture, and urban planning. It will present a guideline for regenerative design.

INTRODUCTION

02 INSIDE-OUT APPROACH

2.1 S TO XXL SCALE

SCALING METHODOLOGY The approach of this Case Study thesis will be the “Inside-Out” approach. This approach means that the project will be introduced from the S scale and eventually understood within the larger scope. The concepts developed throughout this thesis are to be applied to a Case Study at the architectural scale, S. This refers to the building and plot, which is the statement area in this project. This thesis argues the need to blend, or even remove, the threshold between architecture and urban design. This means working with all scales related to the project area - S, M, L, XL, and XXL. The S scale refers to the project area, be it a building or plot. The M scale is considered to be the district or neighborhood surrounding said project area. The L scale is the city it's in. The XL scale is the province and the XXL scale is the country, or climate zone.

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

It is to be noted that the definition of these scales can change based on certain geographical conditions, but in the case of this project, these are how they will be defined. The importance in using such scaling methodology is to understand the genus loci of the site as well as its overall impact in the larger scales introduced.

Project Area CITY WEST

District CITY CENTER

S SCALE This the project development area - be it an individual building, building blocks, or plot. In this project, the area is known as City West and is to be developed into 5 housing blocks west of the City Center.

M SCALE This is the scale of the project area’s surrounding neighborhood. It includes the district the site is located in. In this project’s case study the district is the City Center and develops a 1.000 m radius around the project area.

L SCALE

City NIEUWEGEIN

This is the scale where the relationship between the architecture intervention and the metropolitan condition can become meshed generative forces. It can be seen as the city in which the project area is located. For this project, the L Scale refers to the city of Nieuwegein.

XL SCALE

Province UTRECHT

This scale denotes the urban terrain that goes beyond the infrastructure of the city in which the project area is located. This means the province, state, or region the city is in. The city of Nieuwegein is in the province of Utrecht - the fourth largest city and municipality of the Netherlands.

XXL SCALE

XXL

Country/Climate NETHERLANDS

This scale refers to the country or climate zone the project area is in. It is important to understand the context in which the design will be in within a larger scope, as well as its impact at this scale. For this project, this scale is defined as the Netherlands. Its terrain is mostly coastal lowland and reclaimed land through polders. Its climate is temperate maritime. Precipitation such as rain is typical throughout the year, meaning there are no noted dry seasons - which supports the concept of rainwater use throughout this thesis.

APPROACH

2.2 CASE STUDY

[S] PROJECT AREA: CITY NIEUWEGEIN WEST The municipality of Nieuwegein, a growth-city within the province of Utrecht, wants to develop one of the most sustainable and lively city centers, along with its surrounding residential development, in the Netherlands. The station area is to become the identity and calling card of Nieuwegein through an increase in greenery and sustainable technologies. The liveliness and attractiveness are added through the new homes being built. With the construction of these new homes, in Block B1-2, and C1-5, the municipality wants to meet the high housing demand in Nieuwegein. In November 2018, the municipality of Nieuwegein and the Provincial Council of Utrecht created a fund for the development of the station area. From there, zoning plans for the tram/bus station and Block B1-2 were realized. Currently, the demolition and construction of Block B1-2 and the station area are underway. This leaves room for design intervention and suggestions of Block C1-C5. (“City West” n.d.)

[S/M] SITE PROGRAM

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

AREA STATEMENT: CITY WEST DESIGN GOALS

CIRCULARITY The City West design helps to create a closed loop for each natural or man-made product by transforming the linear resource flow into a circular flow. (Example: recycled building materials, stormwater harvesting). GREENERY AND NATURE INCLUSIVITY Maximum greening, stimulate a rich plant and animal life, future-proof (climate adaptive) solutions.

ENERGY Optimal heating and cooling systems.

WATER Reuse of water in the area and improve residential climate.

MOBILITY Safe cycling and walking routes. East-West route with bicycle bridge over Doorslag. North-South route with renovation of the Kolfstedetunnel. Electric (shared) cars. Parking standard 0.5 including shared cars. Accessible for disabled people.

USERS Housing meant for starters (young people), couples, young professionals, elderly who want to live in an apartment, and persons looking for a care home.

[S] BUILDING BLOCK (C1-C5) GUIDELINES 700-900 homes mix of social, medium and private sector housing varying building heights descending from Zuidstedeweg to Spoorstede (tram track) at the Zuidstedeweg max. 50 m + one tower of max. 70 m at the Spoorstede the basic height is max. 20 m with height accents of max. 36 m

APPROACH

100m

[M] CURRENT DESIGN AND LAND USE The current proposal meets the City West building guidelines, but lacks the spatial design and infrastructure to support a circular and green inclusive design. This is partially because the design does not take into account the climate of the area large shadows will cover the site and inhibit green growth within the courtyards that are meant to be seen as public use. There are definite boundaries between the built and the unbuilt environment.

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

Commercial/Retail Residential

Church

Commercial/Retail

Medical

Church

School

Medical

Housing School(proposed)

Housing (proposed) Station (proposed)

Tram Line(proposed) Station Road

Tram Line

Road grass Common Common grass

Forest

Park Park

Green roof Green roof

[S] CURRENT PROPOSAL: CITY WEST (C1-C5)

APPROACH

[L] CITY DEVELOPMENT GOALS

The City of Nieuwegein is creating a vision for the city that emphasizes sustainability. Space within the city is limited, which is why optimal mix of sustainable ambitions must be met for the maximum results. The development plans include, a ‘pause landscape’ with initiatives aimed at recreation, education and sustainable energy. The Rijnhuizen neighborhood will emphasise outdoor activity within a mixed residential area. The city center has the ambition to become the most sustainable city center in the Netherlands, to be surrounded by greenery and water with accessible and inclusive transport.

B C

Galecopperzoom: Solarpark + recreation

Rijnhuizen: Green Neighborhood

Binnenstad: City Center + City West

2000m

Blooming City by Bureau B+B

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

Stadskwartier by DOK Architecten

Kunstcluster by DOK Architecten

[L] CITY INFRASTRUCTURE Cities are made of three types of infrastructure: Grey, Green, and Blue. The Grey infrastructure refers to buildings, roads, and other urban constructions that make up the urban fabric of a city or place. Green infrastructure refers to the vegetation - trees, lawns, parks, fields, forests, etc. The Blue infrastructure refers to water elements like rivers, canals, ponds, wetlands, floodplains, and water treatment facilities. In the city of Nieuwegein, the leading infrastructure is the Grey. Consequently, the development of the city caters to and relies on such infrastructures.

Project Area

Commercial

Forest

Residential

Agriculture

Industrial

Sports Field

Medical

Water

Points of Interest City Center, WWTP

2000m

GREY: ROADS

GREY: URBAN FABRIC

GREEN

BLUE

APPROACH

[XL] SATELLITE CITY The development of Nieuwegein began as a Satellite City for the overflow of population in Utrecht. Along with many other city centers in the 70s and 80s, Nieuwegein was planned in a very car-centric manner (Elshof and van den Brink 2015).

UTRECHT

12 km 20 min

NIEUWEGEIN

[L/XL] EVOLUTION OF NIEUWEGEIN

1984

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

2000

2020

[XXL] WITHIN THE NETHERLANDS The project development plans for the city of Niewuegein aim to ultimately create the most sustainable city center within the Netherlands by 2040. Currently, the Netherlands is home to one of the largest urban complexes in Europe known as the Randstad. It consists of four main urban centers: The Hague, Amsterdam, Rotterdam, and Utrecht. Utrecht is noted as an important cultural center within the Randstad. The design proposal must take into account the project area's connectivity (be it grey, green, or blue) to each of these major cities for it to be reviewed as the most sustainable city center within the Netherlands.

AMSTERDAM

THE HAGUE

UTRECHT

DELFT

ROTTERDAM

EINDHOVEN APPROACH

03 REGENERATIVE DESIGN

3.1 BLUE-GREEN INFRASTRUCTURE

As addressed in the prologue, increased urbanisation along with climate change, presents a multitude of issues for the city: increased pressure on essential resources such as food and water, loss of biodiversity; increased air and noise pollution due to transportation; increase drought that leads to urban heat island effect and land subsidy; flood risk; and overall increase risk of ill health for the user. NATURE BASED SOLUTIONS Nature-Based Solutions have proven benefits in reducing such urban pressures. The key advantage is that this solution is vegetation based, the construction and operation of the design has low carbon and material footprint. The other benefits include reduction of water and air pollution, mitigation of flood risk and heat islands, increase of resource efficiency, and given spaces for recreation and urban agriculture. The social and economic benefits can be seen through improved financial and aesthetic property values, job creation, and improved mental health through promotion of healthier and active lifestyles (Bush and Doyon 2019).

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

The benefits of nature-based design solutions and biomimicry, the act of using nature as a model for human inventions, are evident (Figure 1). These practices can be applied when urban planners and designers give priority to the Blue and Green infrastructure. CITY AS THE PROBLEM Historically, urban planning was focused on the development of the grey infrastructure. As humans inhabited existing blue and green infrastructures, roads and settlements were formed to help us move across the landscape and find safe places to live. Currently, the grey infrastructure in most cities and rural areas, like in the case of Nieuwegein, have outweighed the blue and green infrastructure. This causes major issues for the urban water cycle, as runoff tends to be polluted from grey infrastructure and development. FIGURE 1: NBS - related Ecosystem Services ( Bozovic et al. 2017)

CITY AS THE SOLUTION Cities are hotbeds for new development; this gives opportunity to counter the challenges they will face in the coming years. Designing with blue-green grids - an emphasis and support of the blue and green infrastructure, will support healthy urban living through the development of wide range ecosystem services, such as bioswales, stormwater harvesting and gardens. These grids will lead to the transition of cities becoming circular. (“Urban GreenBlue Grids” n.d.). A circular city embeds the principles of a circular economy across all its functions, establishing an urban system that is regenerative, accessible and abundant by design (Ellen MacArthur Foundation 2017). FIGURE 3: Design Principles for Blue-Green Infrastructure ("Adaptive Circular Cities" n.d.)

FIGURE 2: URBAN RUNOFF POLLUTANTS

STRATEGY

Regenerative design is the evolution from sustainable design. Regenerative systems create circular loops allowing for adaptability and opportunity for development of resilient ecosystems. Regeneration creates positive impacts on the environment surrounding grey infrastructure rather than simply reducing the negative ones. Sustainability is viewed as a “steady state of equilibrium”, but with regenerative design, there are opportunities to go beyond “net-neutral” to “net-positive”. The fundamental principles of Regenerative Design are to design in the context of the place, to co-evolve and adapt humans and nature, and to conserve and encourage biodiversity.

AP AD B TA

THREE MAJOR REGENERATIVE DESIGN PRINCIPLES: CONTEXT Designing with an understanding of the site's location, its unique dynamics and relationship to the surrounding environment and natural living systems.

ADAPTABILITY Designing as the evolutionary process of adjusting to new environments or to change in their current environment. Creating flexible boundaries and surfaces.

UTILISATION Designing for the preservation and efficient use of resources, through threedimensional spatial intervention and effecient use of climate elements. It goes beyond preservation design by recognising human activity as part of the natural ecosystem.

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

CONTEXT

ILI

UT ILI SA TI ON

3.2 REGENERATIVE DESIGN PRINCIPLES

CONTEXT This principle can be understood by the designer as site analysis. The layers and complexities of the project area must be reviewed and acknowledged for efficient integration and use of space. This means an analysis of circulation, types of spaces (public, semi-public, and private), and certainly climate. Context is the starting point for the other two design principles to follow.

ADAPTABILITY This principle considers the flexibility and deconstruction of the site's limit and current boundaries. This is done literally by stretching boundaries through building techniques such as cantilevers, or in a more representative through blue-green connectors. The driving factor for this design principle is evolution, and the adaptation and integration that must accompany both the social and environmental changes to come.

UTILISATION This principle includes the use of both the horizontal and vertical planes for optimal resource and spatial application and function. By designing for the utilisation of both natural and artificial elements, there is reduced waste of precious resources such as water (be it domestic wastewater or stormwater). This design principle supports nature-based solutions by giving space for existing and future natural resources to thrive.

STRATEGY

CONTEXT

To design with the context of the project area is to understand its layered complexities and integrate it with benefit to the surrounding environment. The design criteria related to context in the area statement of the City West in Nieuwegein is as stated: CIRCULATION In order to integrate the design within the surrounding environment of the City West, the circulation should give ranking to the pedestrian, cyclist, and tram/bus user. These modes of transportation, as opposed to the automobile, have less impact on the environment and can support healthy ecosystems and lifestyles.

[S/M] CIRCULATION + VIEWS

Entry Points Public Transit User View Automobile User View Pedestrian View

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

CLIMATE

USE OF SPACE Integration with the existing environment of the project area also means giving scale to the uses of space. This means putting emphasis on public space and semi-public space, while still providing ample private space. The hierarchy will begin with semi-public space, as it provides security for not only the users but also the environment - protecting it from possible vandalism or other misuse. Public Space refers to urban space that is easily accessible to the general public. Semi-public space is similar to public space, but has a greater degree of control exerted over its allowed access. Finally, private space is exclusively for the use of the residents of a property, so this would mean private spaces “open spaces” like balconies or possible roof gardens. See Figure 4.

The final design criteria related to context is to design for and with the site location’s climate. In the case of City West Nieuwegein, there is a prevailing South Wind as well as certain sun and shade patterns that should be taken into consideration when designing certain public, semi-public, and private spaces.

PRIVATE SEMI-PUBLIC PUBLIC

[S/M] WIND + SHADE PATTERNS (BUILDING CONFIGURATIONS)

Spo

o rs

e ted

[S] PROPOSED BUILDING BLOCK (C1-C5) GUIDELINES 700-900 homes mix of social, medium and private sector housing varying building heights to avoid heavy wind channeling max height of buildings 50-60 m to avoid major shadowing + tower at NW corner at the Spoorstede the basic height is max. 20 m with height accents of max. 36 m

STRATEGY

ADAPTABILITY

Adaptable design anticipates change and absorbs its consequent effects. It is the manipulation of spatial domains and boundary lines for optimal integration and evolution of the project area. The design criteria related to adaptability in the area statement of the City West in Nieuwegein are categorised in Re-Demarcation and Use of Spatial Domains. RE-DEMARCATION The current boundary of the site is determined by road infrastructure. To uphold these boundaries would be to continue giving priority to the automobile and miss the opportunity to connect natural surrounding elements - such as green spaces or bodies of water. The goal of re-demarcation is to stretch the limits of the project area to create better site connections, more space for biodiversity, and an improved relationship to the larger scale network of blue-green infrastructure. This is done

STRETCHING THE BOUNDARIES

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

through the manipulation of building typology and proposal of increased green spaces. By leaving voids open at the ground level, buildings are able to hang over the current boundaries and function as living spaces for not only the residents but also flora and fauna. MODIFICATION OF SPATIAL DOMAINS The key principle of adaptable design is that it is able to integrate and evolve within the area to be developed. This is achieved through the manipulation of five spatial domains: the roof, facade, inner [building], ground plane, and subsoil. The subsoil, as described in the water concept, has the potential to operate as a clean and excess water storage. The ground plane can be manipulated through terrain excavation and fills as to create a natural flow for the stormwater to be utilised or evaporated on-site. The facade is a spatial domain that can become an area for flora and fauna to flourish - such as the creation of living or green

walls. It also can become modular to provide more space for green and natural flows for water. The roof can also be seen as a space to evolve into a living ecosystem and support an increase in biodiversity by developing extensive and intensive green roofs. Lastly, the inner spatial domain, being the inside of the building, is important in the concept of adaptability because this is the space in which the resident or users is expected to spend most of their time, especially when the weather does not permit for outside activity. This means the internal space must act as the central framework in the ecosystems continuously evolving around and on it.

Subsoil

Ground Plane

Roof

Inner [Building]

Facade

FIVE SPATIAL DOMAINS

SPATIAL APPLICATION

STRATEGY

UTILISATION

Utilisation design promotes the efficient and practical use of resources on the project site. This principle is arguably the most relevant to the urban water concept. In this section three water utilisation scenarios will be presented, but only one will become the focus for the design of this project. The design criteria related to utilisation in the area statement of the City West in Nieuwegein are categorised in Separation of Flows and Spatial Domain Interventions. SEPARATION OF FLOWS The most commonly used method of water drainage in the Netherlands, and many other European countries, is a combined collection - meaning the combination of grey and black water. As defined previously, grey water is wastewater from showers and baths, washing machines, and bathroom sinks.

FLOW SCENARIO

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

Black water is defined as water from the kitchen sink and toilets. The third water type that often is drained along with wastewater is stormwater. Urban sewers will become clogged and bottle-necked with the combination of domestic waste and city debris, sediments and plant waste - especially during heavy rainfall events. Clogged sewage systems are not the only problem when waste and stormwater are combined. There is a missed potential in stormwater and grey water reuse and utilisation when the flows are mixed. The solution is to separate these flows. Separate sewer systems eliminate any combined sewage overflow, which in turn helps to prevent pollution. It can also mitigate the problem of flooding by increasing holding capacity. Another benefit of separation is that it optimises the performance of the wastewater treatment plant. Most importantly, the separation of flows in the drainage system allows for stormwater to be used as a resource. Although costly and disruptive to change existing wastewater systems, the pros outweigh the cons and in the long-term the efficiency and longevity of a separated system will end up paying for itself, giving a successful return on investment.

By using stormwater and potentially greywater as a resource through the separation of flows, the regenerative design principle of utilisation is supported. When rainfall occurs on the project area, it will no longer drain off site, but will remain on site through the five steps outlined in the urban water concept. Rainwater will be collected, held and treated, and then seasonally or temporarily stored for future use. This concept can be applied to greywater as well, but the collection process will be different. Tubes will carry domestic waste to the basement of the building where grey water retention tanks will store and treat the water for reuse. The application of the treated blue and grey water can be used for non-potable demand such as irrigation or toilet flushing. The black water will be sent to a wastewater treatment or treated on-site by a local technology such as, Desah.1 By separating the water flows, the practical and efficient use of the project site’s resources can be in effect. This is the key concept of utilisation.

1 SUSTAINABLE WASTEWATER TREATMENT TECHNOLOGY. HTTPS://WWW.DESAH.NL

STRATEGY

BLUE FLOW: RAINFALL EVENTS

SCENARIO TWO: Water for Green Spaces and Households

The spatial design must accommodate for the rare, intense rain event of 50-70mm/hr. However, it should be noted that 95% of the time the rain rate in the Netherlands is typically below 15 mm. The calculation of rainfall rate is necessary to correctly size the buffer and retention area. Although the design should be able to handle the rare heavy rain event of 50, 70, or 90 mm, the design will propose the utilisation of the vertical plane for these moments, as opposed to the horizontal.

Scenario One + Toilet water comes from UWB. Reuse of water for urban spaces and household functions (toilet, washing machine, dishwasher..). SCENARIO THREE: Water for Green Spaces and household, no wastewater to WWTP Scenario 2 + Black water treated through vacuum toilet, GFE via grinder. Fermentation of local black water.

GREY AND BLACK FLOW

SPATIAL DOMAIN INTERVENTION

The Litres per day of grey and black water will differ depending on the amount of residents in the building blocks. For this project, around 1620 residents will be accounted for. The consumption of grey water is set to be 85 l/d and black water 8 l/d. It is valuable to note so that the buffer and treatment of these discharge flows can be correctly dimensioned. However, this information will not be applied to the design proposal.

In order to utilise the on-site resources of the project area, interventions must take place on the five spatial domains recognised in the design principle of adaptability. The proposed interventions not only support the urban water concept, but overall climate resilience for the urban environment. The domain of the roof and facade are able to facilitate interventions such as blue and green roofs and green facades. The two can work together depending if the designs are sloped or flat. See figure 4.

The scenarios are outlined to give suggestions for water use in the project area. Scenario one is what will be applied to this project.

The main spatial intervention domain is the ground plane. As a whole, the ground plane can be viewed as a bathtub model, naturally allowing the rain to fall inwards of the site. Or it can prepare buffers around its edges and lead the water to those spaces. There is also opportunity to combine these two models - which is the preferred and optimal configuration. See figure 5.

SCENARIO ONE*: Water for Green Spaces Drinking water will not be used for green spaces or the toilet. Reuse of rainwater through detention. Reuse of rainwater via Underground Water Buffer. Separation from wastewater. Purification of greywater via technical system (active sludge nanofiltration), disinfection water, and heat recovery. Storage of rainwater and treated grey water in the UWB.

Roof: FLAT

Roof: CASCADE

FIGURE 4: Roof and Facade flow scenarios

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Facade: FLAT to LIVING WALL

Facade: FLAT to PITCHED LIVING WALL

On this domain, there are many possibilities to utilise the site’s resources. For example, permeable pavement can be used to avoid on-site flooding. Bioswales and the lowering of terrain can allow for retention and infiltration of rainwater. Urban forests and adding trees or vegetation to streetscapes and paved areas can provide cooling through shadows and an increase in biodiversity. On the ground plane, there is also opportunity for fountains and water plazas that can achieve rainwater retention and provide cooling properties as well as recreational use. The next spatial domain to identify is the inside of the building, this is where the intervention of domestic wastewater treatment will occur. Although not relevant in the water concept, the building also creates climate resilience through its materials. If the building is built from dark materials with less mass such as wood or other porous materials it will absorb less heat making its surroundings cooler.

Ground: BATHTUB MODEL

The last domain to utilise is the subsoil. Even though the intervention that occurs in this domain will not be visible, it is no less important than the others. In the subsoil, underground wells can be implemented, utilising the space vertically and storing its resources for future use or to avoid excess runoff. VERTICAL INTERVENTION As stated previously, the design must accomodate for the rainfall events of 50, 70, and 90 mm. This means there must be sufficient space for the increased rainfall. The usual solution to this is to develop buffers on the horizontal plane that can retain the water. But these buffers only will be utilised 5% of all rainfall events. That means that 95% of the time these buffers, at large cubic volumes, will be of no use. The proposed solution is to utilise the vertical plane. The suggestion is to raise built areas 10 cm, allowing for 100 mm of rainfall storage. See Figure 6.

Ground: To EDGES

Ground: BATHTUB + EDGES

FIGURE 5: Ground plane spatial and flow configurations

50 MM STORAGE 1/3: INSTALLATIONS

2/3: GREEN, BLUE, SOLAR HOLD 10-15 MM FOR 1 WEEK OF WATER SUPPLY.

SUPPLY FROM UWB (UNDERGROUND WATER BUFFER) OR TREATED GREY

SURPLUS AS DELAYED DISCHARGE TO OWB, OR SURFACE WATER

100 MM STORAGE

FIGURE 6: Roof and underground storage scenario

UWB

STRATEGY

ROOF The roof is the first spatial domain stormwater touches. This is the initial plane where the water function and application points begin. In regards to the roof, the function of collection and retention can be in operation. For water application, there is use to irrigate the green or living roof.

Collection

Retention Detention

Treatment

Storage

Use

FUNCTION COLLECTION Stormwater is collected on a designated green roof - which can be categorised into intensive or extensive. Extensive green roofs are the simpler of the two, with mostly ground cover covering plants or low-growing perennials. It is occasionally accessible to the public, but typically does not provide security for heavy foot traffic. The addition of solar panels on an extensive roof can be seen as a good combination for an increase in environmental and financial benefits. Intensive

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

green roofs are meant to handle more user activity and can support plants such as shrubs and larger trees. These types of roofs can even provide space for ponds and recreational spaces. These give opportunity for creative design and an increase in biodiversity. RETENTION AND DETENTION Once collected, retention or detention of stormwater can take place on the green roof. Retention refers to holding the volume of water for an indefinite period of time, eventually being taken up by the plant life that evaporates back into the atmosphere. Detention involves more purposeful intention in its system, temporarily detaining stormwater, giving room for treatment, and then discharging it as cleaner runoff. Detention provides opportunity to delay and control the flow of stormwater runoff to prevent untreated overflow off of the roof.

APPLICATION USE: Irrigation The treated stormwater runoff, as well as the treated grey water, can be pumped back onto the green roofs for irrigation of the vegetation.

OTHER FUNCTIONS SOLAR ENERGY The roof is also a domain to reduce electricity production emissions and cost. This is done by the implementation of solar panels. These can accompany the living roofs, whether extensive or intensive.

The roof can be used for collection, retention and detention of stormwater as well as an inviting place for the user to gather and enjoy the greenery.

STRATEGY

FACADE Following the raindrop, the facade is the second spatial domain stormwater touches. This gives reason for the installation of green walls. There are two types of green walls relevant in this project: green facades, which are extensive systems with climbing plants generally rooted at the base of the facade, and living walls where the vegetation is attached to the facade and fully integrated on the surface of the external wall.

Collection

Retention

Treatment

Storage

Use

FUNCTION COLLECTION Stormwater reaches the green wall in a variety of ways, either discharged from the roof or it interacts immediately depending on the wind. In any case, the structure of the green wall can manipulate the movement of the collected rainwater depending if it is sloped or not. If the structure the living wall or green facade is attached to is sloped, it can provide a better directional flow of where the rainwater will go next. It is recommended to place bioswales or ground plane buffer zones under the green wall to capture the rainwater coming from the facade.

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

APPLICATION USE: Irrigation Treated water can be pumped to the top of a green wall where it can be distributed to the plants when needed. Plants on a green wall are easily irrigated naturally by rain or manually/automatically through the pumping system of treated grey and stormwater.

OTHER FUNCTIONS SOLAR ENERGY The facade can also be seen as a spatial domain to harness solar energy through the technology of solar panel windows. (Physee2)

LOCATION AND DESIGN Vertical vegetation grows best on South facing facades. Green walls can be designed with an indirect two or three dimensional trellis, a vegetated mat living wall, hanging pocket, framed box modular, wire cage modular, perforated box modular, slanted cell box modular living wall, or with trough planters.

In relation to rainwater, a green facade is able to act as a buffer, delaying the discharge of rainwater, offering purification and evaporation through the plants. 2 COATINGS, SOLAR AND SENSOR TECHNOLOGY. HTTPS://WWW.PHYSEE.EU/

STRATEGY

INNER [BUILDING] The next spatial domain to be defined for water function and application is the inside of the building. The inner domain does not deal with stormwater, but wastewater. Blackwater is to be treated in the basement and carried offsite to a wastewater treatment plant. Greywater can be reused on the site, once treated.

Collection

Retention

Treatment

Storage

Use

FUNCTION TREATMENT There are two types of wastewater that comes from building use that are to be treated internally. These types of domestic wastewater have been defined previously, therefore as review: Blackwater is wastewater from toilets, kitchen sinks, and dishwashers. The treatment of blackwater is done through local systems implemented in the basement and then carried to off-site wastewater treatment plants. Greywater is wastewater containing lower levels of contamination, such as sinks, washing machines, and showers.

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

STORAGE Greywater is held in a tank located in the basement of the building, before being discharged for irrigation or to another tank for treatment. Its use can be diverted by gravity or through the use of a pump. It is important to note that the tank for greywater is for temporary holding, not long-term storage, as greywater should not sit in a tank for extended periods of time unless it has been treated.

APPLICATION USE: Irrigation The reuse of greywater is strictly for irrigation and should not be used for human interaction such as play or drinking water.

OTHER FUNCTIONS The quality of the indoor environment in a building is important to measure its success for intended use. Spatial function of houses and communal spaces should be oriented to promote views that showcase the landscape and natural settings to provide higher quality living spaces. Orientation also gives opportunity to utilising natural lighting and shading, these aspects and monitoring indoor air quality and thermal comfort are other aspects that can be designed with high environmental quality factors.

By utilising wastewater that runs within the housing blocks, there is opportunity to support living ecosystems that integrate the building. By doing so, the division of built and unbuilt becomes indistinct.

STRATEGY

GROUND PLANE Stormwater reaches the ground plane immediately if there are no interruptions such as the roof and facade. The ground plane is the last spatial domain for stormwater to be collected, retained or detained, and treated.

Collection

Retention

Treatment

Storage

Use

FUNCTION COLLECTION The collection of stormwater runoff on the ground plane begins with an analysis or manipulation of the project area’s topography. It is recommended to use the site’s lowest point as an area for catchment and natural infiltration (ie. pocket park or constructed wetland). The ground surface is the spatial domain that gives the direction to where the stormwater will flow or infiltrate. Other spaces to collect stormwater can be landscape elements built from or in the ground plane such as basins, bioswales, ponds, or even permeable pavers. It is of value to note that the more unpaved surface the project area has (ie. green space), the less surface runoff there will be.

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

RETENTION Green infrastructure intended for retention is used in the collection of rainwater. It is recommended to give priority to catchment areas flowing into areas for retention to provide cleaner water for reuse. In regards to the ground plane, retention areas are recommended over detention ponds because when stormwater is detained at this level it is then typically discharged off-site. To emphasise circularity, retention areas will ensure all stormwater is kept on site and used, evaporated or infiltrated into the ground for storage. Retention is considered a component of low-impact development and can be visualised through the use of rain gardens, bioswales, or ponds. TREATMENT Adjacent to retention elements, is the biofilter that is used to purify the stormwater. Treatment happens with the combination of slow sand filtration, biological degradation, and plant uptake. The treatment the biofilter provides is of metals, nutrients, pathogens and organic pollutants.

APPLICATION USE: Irrigation, Play Water The use of treated and stored water on the ground surface is through irrigation of green space or vegetation, play water, water features and possibly drinking water depending on post-treatment applications.

The ground plane is a critical spatial domain to utilise for an effective urban water system. It is the plane where flooding is to be prevented so as to create a safe and accessible public space.

STRATEGY

SUBSOIL The final spatial domain will come in contact with treated storm and wastewater through the application of storage. Treated water is stored in sand layers deep in the subsurface via infiltration wells. The depth of infiltration will depend on the project area’s soil composition, but typically wells are placed near stable soil types such as clay.

Collection

Retention

Treatment

Storage

Use

FUNCTION STORAGE In times of surplus, after the rainwater is collected and retained it is injected into the deeper subsoil (approximately 15-25 m below ground level) and stored in relatively large quantities for future use during a period of demand. Through the utilisation of the subsoil, the spatial use on and around the ground level is optimised. This technique is referred to as Aquifer Storage and Recovery (ASR). After the first step of filtration, runoff rainwater is infiltrated via a drilled injection well into an aquifer. The benefits of this system is that it protects

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

against external influences so the quality of the water stored remains good for a long time. This gives opportunity to future reuse and can provide in times of drought.

APPLICATION USE: Irrigation, Play Water Seasonally stored treated grey and stormwater can be pumped up to the ground level when needed and used in irrigation, play water, or in landscape elements.

SOIL STRUCTURE AND LOCATION The soil structure determines the application to the underground water storage and its location. Figure 7 shows the soil structure occurring in the project area, City West of Niewuegein. The location of the ASR depends on the soil structure and should be placed in open space whether under paved or green areas, at least 50m from the energy well.

FIGURE 7: Soil composition of City West, Nieuwegein.

The utilisation of the subsoil is what makes the urban water concept three-dimensional and unique. Aboveground storage of rainwater takes up valuable space, so the solution is to store excess and clean rainwater in the subsoil vertically.

STRATEGY

04 DESIGN PROPOSAL

4.1 DESIGN STRATEGY

[S] CONTEXT

The spatial strategy establishes circulation patterns and use of space. The context analysis of the project area reveals that its current infrastructure supports vehicular circulation over pedestrian. The proposed strategy does this by removing vehicular access to the SE entrance and positioning parking underground. The bus no longer cuts through the site, but circulates around the designated bus area towards the city center. Another reason vehicles do not penetrate the project area is to create safer access points and increase liveable green spaces. Pedestrian circulation follows the

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

SPATIAL STRATEGY Bus circulation Elevated ped. circulation Pedestrian circulation Car circulation No car access Central meeting point Building footprint Platform/cantilever Stairs Green/open space Water plaza way rain flows on-site and the access points are designed to encourage green space experience and interesting views. Green spaces can be identified as transition points from one area to another. The central meeting area will highlight the use of water and function as a water plaza.

APPLICATION

[S] ADAPTABILITY

The adaptability strategy applies the concept of flexibility and manipulation of spatial domains. The current infrastructure gives importance to the grey - which is typically fixed infrastructure. The strategy proposal aims to transform fixed spaces into flexible ones. This is done by creating connection points as living, green systems. The current boundary is broken through the use of spatial domains (connector planes such as platforms, cantilevers, or ground vegetation).

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

EXTENDED BOUNDARIES Building Platform/Cantilever (Built connector) Grey connector (Public space connector) Flexible boundary Fixed boundary Blue connector (view connection) Green connector (vegetation connection)

APPLICATION

[S] UTILISATION

The proposed strategy of the water system is based on a circular and decentralised model. Currently, the system relies on a ring model that frames the project area. The problems this causes are bottlenecking and lack of accessible reuse possibilities. By decentralising the system, there is more control for supply and discharge of domestic wastewater. The treatment and retention tanks will be located in the basement of the housing blocks. Overflow from the decentralised lines will connect to the centralised system. Black water treatment is proposed on site, but most

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

WATER SYSTEM [Domestic Waste] Centralised system

[Rainwater] Buffer (for overflow)

Existing (ring) Catchment area Decentralised system Minor lines

Overflow

Water plaza: underground storage, treatment + use Green space: treatment + use

Grey water buffer + treatment Black water buffer + treatment likely will be discharged to the Waste Water Treatment Plant (WWTP). As for the rainwater, the largest catchment area is identified as the bus station. From there the rainwater will be transported naturally or through tubes to retention and treatment spaces, until it will be stored in the underground storage area for future reuse.

APPLICATION

4.2 DESIGN PROPOSAL

[S] DESIGN: AXONOMETRIC

The design proposes the transformation of the built environment into “unbuilt”. The “unbuilt” refers to the landscape spaces. Each built space becomes the foundation for living spaces. Roofs are no longer just a roof, but green and walkable spaces for ecosystems to thrive on. They also function as a space for solar energy to be harnessed. Platforms and cantilevers provide climate protection and buffer areas for rainfall and wind. Green facades also act as climate protection and buffers, as well as improving air quality (especially that coming from street pollution). The

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

increase in unbuilt spaces not only encourages the growth of flora and fauna, but establishes inclusive design through accessible routes of well integrated ramp and elevator systems.

APPLICATION

DESIGN: EXPLODED ISOMETRIC

When rain falls onto the project area, the horizontal plane created from green roofs and platforms will collect and retain it until it is discharged to the ground level. The ground plane is designed to naturally offer flows towards biofilters and green spaces for ground infiltration. In the case of a 50-70mm/hr rain event, the project area is framed by buffer zones that will provide retention and biofiltration. Surface water is also an option for the overflow. Once the water has been collected, retained, and treated it will enter into the Underground Water Buffer for seasonal and temporary storage. This water can be pumped back to the ground level for irrigation of green spaces, roofs, and facades or used for play water. The design proposes working vertically. This concept comes from following the raindrop. The different levels provide a cascading effect that can benefit the horizontal space of "collection" areas. The increase in the horizontal planes on different levels is proposed to encourage biodiversity growth and effective retention space for rainfall events (as well as high quality spaces for residents).

[S] CIRCULAR WATER DESIGN Following the raindrop

Roof

Facade

Inner [Building]

Ground Plane

Subsoil

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

The developed space for green systems is able to utilise existing blue sysems and create a circular water design. This is done by the use of the subsoil in storage and reuse. These green systems evolve and exist through the circularity of water use on the site. In this way, built forms become "unbuilt" meaning they become living and "natural" spaces.

[30m to 50m] Private Green Roof

[12m to 50m] Housing

[8m to 12m] Semi-Public/Public Green Roof

[S] BUILT BECOMES "UNBUILT" Layered green and open space

[0m to 12m] Mixed Use Housing and Retail

[0m to -1.5m] Public green spaces and water plaza

[0m to -4m to -25m] Underground parking and water buffer/ storage

APPLICATION

CITY WEST DESIGN GOALS

[S] CIRCULARITY Spatial Domains

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

This section will explain the variations from the current design to the new proposal. These diagrams will showcase the realisation of the Area Statement: City West Design Goals.

CIRCULARITY The design proposal promotes the concept of circularity in the function of each spatial domain outlined within this thesis. The driving approach is verticality - this is what creates physical and spatial circularity. Each domain supports each others’ function and application in creating a circular water and green system. Circularity follows the principles of nature, meaning the built form must be able to adapt to the processes of the site-specific environment.

Roof

Ground Plane

Facade

Subsoil

Inner [Building]

CIRCULARITY

GREENERY AND NATURE INCLUSIVITY

ENERGY

WATER

MOBILITY

USERS

APPLICATION

MODIFICATIONS

GREENERY AND NATURE INCLUSIVITY As previously mentioned, the design proposal transforms the built to unbuilt. This affirms the goal of creating a green and nature inclusive design. In comparison to the existing City West design, this proposal makes use of the layering vertically of the horizontal plane to create more green areas. EXCLUSIVE TO INCLUSIVE The current design is based on the courtyard model. This means each green area is enclosed by the building. The proposal breaks the walls of the courtyard model and creates open and inclusive green spaces. The openness of green spaces encourages safer accessible routes and better nature integration and harmonisation. Not to mention, the shadows casted in the courtyard model would affect the growth of the vegetation. In this design proposal, the sun directly provides energy for the growth of the green roofs and facades.

[S] GREENERY AND NATURE INCLUSIVITY Layered Living Systems

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

[S] CURRENT DESIGN Exclusive Green Spaces

CIRCULARITY

GREENERY AND NATURE INCLUSIVITY

ENERGY

WATER

MOBILITY

USERS

APPLICATION

MODIFICATIONS

WATER Considering the design as a whole is based on the urban water concept, the goal to reuse water on-site is prioritised. Water becomes a circular resource, starting from the raindrop on the roof to the facade, to the ground plane, to the subsoil for storage and future reuse. Residential climate is improved through the effective supply and discharge of domestic wastewater, utilising the grey for irrigation purposes. The horizontal planes are to become catchment and retention areas during rain events. The subsoil is to hold the treated rainwater seasonally. The green areas are to be irrigated by cleaned stormwater. The system works circularly. ENERGY

[S] WATER Collection, Retention, Treatment, Storage, Reuse

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

The goal of the city is to optimise heating and cooling systems; this is to be done through natural energy and absorption methods from the sun and vegetation. Solar energy can be harnessed passively and actively. Passive

solar design systems exist through window and facade design, creating passage of energy to walls and floors that absorb and store heat energy. Solar panels on roofs are active energy production. The photovoltaic systems convert sunlight directly into electricity that can be used to heat, cool and light the buildings. Roofs not dedicated to extensive and intensive green roofs will support solar panel installations.

[S] ENERGY Harnessing Solar

Green facades are natural absorption planes for heat and water, which makes them a source of urban heat management and reduction of building energy consumption.

CIRCULARITY

GREENERY AND NATURE INCLUSIVITY

ENERGY

WATER

MOBILITY

USERS

APPLICATION

MODIFICATIONS

MOBILITY The circulation patterns follow the flow of the rain. This is to provide the user with an interesting and interactive green space experience. The bicycle routes are provided through bridges, but cycling through the site is not prioritised like pedestrian circulation. This is because the project area is around 6,5 ha and does not require intensive cycle paths. The design prioritises circulation that causes the pedestrian to slow down and enjoy the surrounding flora and fauna. The site is made accessible through ramps and elevators. Car circulation will not exist through the site, but underground parking for shared electric cars and personal automobiles will be provided. USERS

[S] MOBILITY Priority to Pedestrian

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

The housing blocks contain 4,5 m high ground level public accessible floors. This encourages interaction between residents and the project area users. All other floors are between 3,5m to 4m high. Public gathering spaces are

provided on the ground level and 8-12m high green roofs. All other accessible green roofs are for private residents such as the elderly.

[S] USERS 900 Housing Units

CIRCULARITY

GREENERY AND NATURE INCLUSIVITY

ENERGY

WATER

MOBILITY

USERS

APPLICATION

150m

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

APPLICATION

[South to North] POCKET PARK AND WATER PLAZA [XS] RAINFALL FLOW: Overflow to surface water or edge

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

AII [S] REFERENCE MAP: Section A

100m

AI APPLICATION

[South to North] PUBLIC ACCESS BIOFILTRATION STAIRS [XS] RAINFALL FLOW: Roof to Biofilter

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

BII [S] REFERENCE MAP: Section B

BI 100m

APPLICATION

[S.East to S.West] GREEN BUILT EXTENSION OVER ROAD [XS] RAINFALL FLOW: Infiltration into pocket park Overflow to buffer

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

[S] REFERENCE MAP: Section C

CII

100m

APPLICATION

[N.East to N.West] STATION AND OFF-SITE ENTRY POINTS [XS] RAINFALL FLOW: Roof to Biofilter/Buffer

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

[S] REFERENCE MAP: Section D DI

DII

100m

APPLICATION

REGENERATION SPATIAL SOLUTIONS FOR RAINWATER

05 FUTURE RESILIENT CITIES

5.1 REGENERATIVE RESILIENCY

CLIMATE RESILIENT CITIES Cities are the most significant sources of impact on natural resource consumption and polluting emissions that alter the natural and climatic balances. This is why climate resiliency has become the leading approach to design in the urban environment. The definition of a resilient city is one that has developed capacities to absorb future shocks and stresses, so as to maintain the same functions, structures, systems and identity ("Urban Resilience" n.d.). Climate resilient cities are capable of reducing and managing the negative impacts they have on the climate and natural environment. It can be deduced: to design for city resiliency is to design for a future-proof urban environment. Future-proof design is the process of anticipating for the future by developing methods that can minimize the shocks and stresses of future climate change. However, future climate-proof is not enough. Instead, cities should strive to design for regenerative resiliency. The current definition of resilience is flawed - as it aims to "maintain" the existing environment, while the existing environment is not good. Regeneration is the key to tackling the future of climate change. It promotes the ideas of integrating

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nature based solutions to transform a space into a living ecosystem. CALL TO ACTION Architects, landscape architects, and urban planners must abandon outdated approaches to "sustainable" design. In fact, they must abandon the word sustainability - it is a greenwashing term that does not represent what is needed in the future of design. As stated previously, architects should not be designing to sustain the current environment. And although It is important that the design does not damage the environment further, this also not enough. It is time to respond to the fact that human activity, especially that of cities, over the last centuries has done significant damage to the functioning of healthy ecosystems. This response is to be done by replenishing and restoring resources through regenerative design.

process that engages and focuses on the evolution of the whole ecological system in which we are a part of. It is also recognised at the highest level of trajectory related to environmentally responsible design. See figure 7. (Reed 2007). This means the natural environment can longer be looked at as a separate entity to our human lives. It is vital we learn to participate with nature, as to create a mutually beneficial relationship. The realisation of regenerative design can be done through the key principles outlined in this thesis: context, or understanding the complexities and identity of the project location, adaptability and integration, and finally the utilisation and restoration of natural on-site resources.

By Reed's definition, regenerative design is the

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5.2 CONCLUSION

SUMMARY The main objective of REGENeration is to introduce future hydraulic criteria for spatial quality within the urban environment. This is significant because of the climate challenges cities currently face, specifically those related to the urban water cycle. The basis of the hydraulic criteria outlined is established in the urban water concept. The urban water concept emphasises vertical spatial intervention over the horizontal plane. The reason is to optimise the use of space and utilise resources efficiently. This is one of the key principles in the strategy of regenerative design. The project itself demonstrates the advantages of designing with said strategy. REGENeration uses the "inside-out" scaling approach and applies it to a case study. The real estate

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development project of City West, is an on-going project for the municipality of Nieuwegein in the Netherlands. Their goals have been clearly defined; the main one being to claim their city center as the most sustainable city center within the Netherlands by 2040. Although this project criticises the use of the term "sustainability", the intention behind this goal is valued. It is able to be accomplished by regenerative design practices. These practices are highlighted through the three key principles: context, adaptability, and utilisation. The method of utilisation is fundamental to the function of the urban water concept.

driving factor is creating spaces for higher quality living. Jan Gehl can be quoted saying, "First life, then space, then buildings - the other way around never works." Higher quality of life is provided through the integration of Blue-Green infrastructure. REGENeration focuses on the depleting resource of water, specifically rainwater. Green cities cannot exist without water; humans cannot exist without water. It is arguably our most precious resource on this planet. It cannot be ignored in all types of future development projects. This project is meant to encourage landscape architects and designers to defend this resource and to evolve from the concept of sustainable design to a regenerative one.

Despite the urban water concept depending on rainwater (and domestic wastewater) harvesting, the

GUIDELINES FOR REGENERATIVE DESIGN

SITE SELECTION + ANALYSIS Align and combine with area statement and infrastructure. Adopt the "insideout" scaling methodology, starting from the S to XXL.

UTILISATION Define project area dimensions and apply the urban water concept. Outline nature-based solutions and make use of the site's existing resources.

INTEGRATIVE DESIGN Apply the key principles: Context, adaptability, and utilisation. Integrate the project into its surrounding environment; design with blue-green infrastructure prioritised so to evolve as a living ecosystem; utilise resources to avoid waste and to create robustness.

OWNERSHIP AND RESPONSIBILITY Working together on circular water systems requires the involvement of each stakeholder from design to operation. For example, the project developer, water authority, water utility, and municipality.

BLUE-GREEN NETWORK Every project area becomes a living ecosystem through blue-green infrastructure. These systems are to be replicated for every new development and are able to connect through nature-based solutions.

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5.3 UPSCALE AND IMPACT

2020

FIGURE 8: Gradual transformation of centralised system to decentralised - by way of individual "bluebloqs" circular water systems.

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2030

NETWORK TRANSFORMATION The goal of the circular water model is to be selfsufficient and an individual working system apart from the centralised water system. To better understand this, figure 8 shows the "bluebloqs", or implemented circular water systems and its gradual transformation at a neighborhood scale. The continuous implementation of circular water systems creates less need for the use of the existing, centralised infrastructure. So by 2050, we can look at a neighborhood, city, and region as a decentralised water system that independently and effectively provides for the space the "bluebloq" is implemented in.

2050

FUTURE RESILIENCY By decentralising and upscaling the circular water systems, cities develop opportunities for resiliency against climate challenges and regeneration from efficient use of resources. If we look at the city scale of Nieuwegein at its current centralised system (Figure 9), it is clear that damages and waste would occur in the event of a flood. As we know, floods are a climate challenge cities must deal with in the future and if their infrastructure is centralised then they risk damages to the urban environment, as well as a missed opportunity to harness water. If the city has adopted a decentralised system of many circular water "bluebloqs", then it has higher resiliency when challenges like a flood come. Figure 10 illustrates this and shows that flood water is managed at small, local scales to mitigate better and make use of climate challenge resources.

FIGURE 9: Nieuwegein and flooding - 2020 [centralised system]

FIGURE 10: Nieuwegein and flooding - 2050 [decentralised system]

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This document has been submitted as a Sustainable Architecture and Landscape Design thesis for the School of Architecture Urban Planning Construction Engineering at Politecnico di Milano.