(PDF) Innovations in urban water management to reduce the vulnerability of cities: Feasibility, case studies and governance

Innovations in urban water management to

reduce the vulnerability of cities

Feasibility, case studies and governance

Innovations in urban water management to

reduce the vulnerability of cities

Feasibility, case studies and governance

Proefschrift

ter verkrijging van de graad van doctor

aan de Technische Universiteit Delft,

op gezag van de Rector Magnificus prof. dr. ir. J.T. Fokkema,

voorzitter van het College voor Promoties

in het openbaar te verdedigen

op maandag 23 november 2009 om 10:00 uur

door

Rutger Ewout DE GRAAF

civiel ingenieur

geboren te ‘s Gravenhage

iv

Dit proefschrift is goedgekeurd door de promotor:

Prof. dr. ir. N.C. van de Giesen

Samenstelling promotiecommissie:

Rector Magnificus, voorzitter

Prof. dr. ir. N.C. van de Giesen, Technische Universiteit Delft, promotor

Dr. ir. F.H.M. van de Ven, Technische Universiteit Delft, copromotor

Prof. mr. dr. J.A. de Bruijn, Technische Universiteit Delft

Prof. dr. W. van Vierssen, Technische Universiteit Delft

Prof. dr. R.M. Ashley, University of Sheffield

Dr. R.R. Brown, Monash University

Prof. dr. ir. C. Zevenbergen, Unesco-IHE

This research was executed as part of the Leven met Water research program, project number

P1002, Transitions to more sustainable concepts of urban water management and water supply.

Most of the work was financially supported by Leven met Water and STOWA (Foundation for

Applied Water Research). Parts of the work were supported by the Municipality of Rotterdam,

Waternet, Municipality of Heerhugowaard, Waterboard Hollands Noorderkwartier, Erasmus

University of Rotterdam, Tauw BV, Ecofys, KWR Watercycle Research Institute and Deltares.

Keywords: urban water management, innovations, local water supply, ATES+, floating

urbanisation, vulnerability, mainstreaming of technologies, receptivity, transitions, urban water

governance

ISBN: 978-90-8559-591-5

Cover illustration: DeltaSync, Bart Roeffen

Cover design: Wenneke Lindemans

v

Summary

Current urban water systems are criticised by many scholars. Negative aspects of the current

urban water system include: effects of urban runoff on aquatic ecosystems, the lack of recycling

of nutrients, the use of purified water to transport waste, land subsidence, high investments and

maintenance costs, and the lack of flexibility to cope with future challenges. Cities show parasitic

behaviour. They extract all required resources from the surrounding area and after using them,

discharge the pollutants to this area. Cities hardly use internal resources of water, energy and

nutrients and require more and more space. Envisaged future urban water systems aim to reduce

the vulnerability of cities and ecosystems. The research was focused on surface water, stormwater

and groundwater within cities. In particular, opportunities that these components of the urban

water system offer to reduce vulnerability of cities were studied. The overarching aim of this

research was to develop understanding how innovations in urban water management can be

realised. This required three things: 1) understanding of the current system, 2) knowledge of

innovations and 3) knowledge how to implement and mainstream these innovations in a societal

context. To address these three aspects, this research applied vulnerability theory to contribute to

better understanding of the current situation. Additionally, the technical feasibility of concepts

that use the urban water surface water and urban groundwater to reduce the vulnerability of cities

to flooding, droughts and energy scarcity was studied. Next to studying the technical feasibility,

the case studies were also used to develop insights in mechanisms that determine adoption and

mainstreaming of technical innovations. The results of the case studies were further substantiated

through comparison with scientific theories, findings from literature, and comparison with the

general results of a national survey among urban water management professionals.

A literature survey was done to make an overview of theoretical concepts of vulnerability. Based

on the results of this research, vulnerability was defined as a framework that consists of four

components. Threshold capacity is the ability of a society to build up a threshold against variation

in the environment in order to prevent damage. Coping capacity is the capacity to reduce damage

in case of a disturbance that exceeds the damage threshold. The third component, recovery

capacity refers to the capacity to recover to the same or an equivalent state as before the disaster.

Finally, adaptive capacity is the capacity of a society to anticipate on uncertain future

developments. This includes catastrophic, not frequently occurring disturbances like extreme

floods and severe droughts. The vulnerability framework shows that vulnerability capacities are

connected. Increasing one vulnerability capacity potentially decreases one or more of the other

capacities. Including all four capacities of the vulnerability framework enables better

understanding of water and climate related vulnerability of urban areas. Moreover, the framework

can assist in developing more complete water management strategies to reduce vulnerability.

Based on this framework it can be concluded that in the Netherlands, current strategies for water

supply and flood control management mainly focus on the first capacity of vulnerability by

increasing threshold capacity. The current water management system is optimised with the

objective of reducing the risk.

One of the objectives of this research was to learn from other countries in reducing vulnerability

of cities to flooding and droughts. The situation in Japan was in particular interesting with regard

vi

to climate adaptation of urban water systems. This country has already an extreme climate that

causes both floods and droughts. Moreover, similar to the Netherlands, it is a highly urbanized,

industrial country with a high percentage of invested capital and population in flood prone areas,

including areas under sea level. Thus, the systems that are in place in Japan can provide us with

ideas how Dutch urban water systems could function in the future. Japan is a country that is

frequently exposed to all kinds of natural hazards including flooding and droughts. In Japan,

there are many examples of urban water management innovations that increase coping and

recovery capacity. A wide diversity of technologies is available to adapt to changes in the physical

conditions. However, also in Japan the flexibility of the centralised main urban water

management infrastructure seems low. Based on the vulnerability analysis, it can be concluded

that in Japan all four capacities of the framework are used to reduce vulnerability of urban

lowland areas.

One of the main objectives of this research was to study the feasibility of using the local urban

surface water and urban groundwater for new functions. Three technical concepts were

investigated. The first technical concept is the use of local urban water resources. Results for De

Draai, Heerhugowaard showed that an entirely self-supporting urban water supply is not feasible.

However, even in a dry year such as 2003, less than 5% external supply is required on a yearly

basis. New urban developments can therefore be much more self-supporting. Water quality

analysis and proposed treatment schemes showed that it is technically possible to produce

drinking water from local resources. The expected costs were low although substantially higher

than connecting the district to the conventional system. Rainwater harvesting appeared to be a

promising technology in this project. The expected drinking water demand reduction was up to

27% on a yearly base. Following this project, rainwater harvesting is still in the process to be

included in the development plans of the municipality on a pilot scale.

The second technical concept is this research was the use of the urban water system as an energy

source. Research results demonstrated that De Draai in Heerhugowaard can be self reliant for

heating and cooling purposes by applying Aquifer Thermal Energy Storage supplemented with

surface water heat collection (ATES+). The district does not need to rely on international gas

distribution networks that might be disrupted in the future by geopolitical tensions, incidents or

terrorism. Price fluctuations on the international energy market have only a small impact on the

heat and cooling system of De Draai. Local energy supply can be regarded as an adaptive strategy

to the uncertainties of the global energy market. The vulnerability of this district is lower than in

case of a conventional system. By cooling the surface water with 1.5-1.6 °C in three summer

months, enough heat is collected to compensate the entire residential heating and cooling

demand. With the concept of ATES+, fossil fuels are no longer required to produce heat for

indoor climate control. Heat from the urban surface water and urban groundwater is used for this

purpose. Electricity is still needed to operate the system, however only for the transportation of

heat instead of the production and transportation.

The third technical concept was the use of the urban surface water for urbanisation. Floating

urbanisation has the potential to contribute to reduce vulnerability of delta areas. During floods it

may contribute to coping capacity. Floating houses will adapt to the rising water level and they

potentially function as emergency shelter during flooding. Because floating houses can be

relocated, they are also flexible, which is a benefit to deal with uncertain future developments

vii

such as climate change. Risks of floating urbanisation include the loss of open space, the

technical quality of floating constructions, and unknown water quality impacts. A potential way to

address this problem is capacity building through well-designed, well build, and well maintained

demonstration projects that are carefully monitored and evaluated. This will produce experiential

knowledge among contractors, local government employees, utilities and residents.

The second part of this research focused on the implementation and mainstreaming of

innovations in urban water management. Theoretical frameworks that were used in this research

include transition theory, the multilevel perspective and the receptivity continuum. Based on

international literature and experience from the case studies, two conditions were identified that

determine the implementation and mainstreaming. These conditions are: including urban water

management innovations in spatial development, and stakeholder receptivity to urban water

management innovations. The Rotterdam case study was done to study how innovations are

included in official policy and spatial planning. Results of this study show that the development

of urban water management policy is currently integrated with urban planning. Planners of urban

water retention infrastructure successfully utilise the opportunities that urban revitalisation

presents by considering the local context. The role of the envisioning project Rotterdam Water

City 2035 has been crucial in changing towards a new perspective. In this policy innovation niche,

for the first time urban planners and urban water experts developed a joint long term vision for

the city. Because it was a non official policy, more radical ideas and a longer planning horizon

were possible than in official policy documents. In this vision, water retention contributes to the

upgrading of neighbourhoods by increasing living quality. Many innovations that were developed

in the project were eventually included in official policy. Examples are green roofs, water

retention squares and floating urbanisation. Mainstreaming was enabled by changes during the

preceding years. It became increasingly clear the water retention objectives could never be

realised in a conventional way. Consequently, urban water management professionals were

receptive to the integrated approach that was applied in the project Rotterdam Water City 2035.

Mainstreaming was further enabled by executive and political support and the presence of change

agents in all participating organisations.

Next, an online survey study was done to gain insight in the potential for transformative change

in the Dutch urban water management sector. The receptivity to transformative change is small.

Even in the survey group of policy experts with a good overview of current urban water

management issues, there is no perceived necessity to radically change urban water management

practice. The professionals are convinced that the societal objectives in urban water management

can be achieved by optimisation of the current centralised urban water system. In addition,

cooperation with other sectors is necessary and five key factors are regarded top priority to be

further improved: 1) Available knowledge about the local urban water system, 2) Trust between

cooperating partners in urban water projects, 3) Experience in connecting water management and

spatial planning, 4) Support and commitment of elected officials to sustainable water

management, and 5) Involvement of citizens in urban water projects.

Another objective of the online survey study was to gain insight in the receptivity of professionals

in the Dutch urban water management sector to innovative technologies. The study addressed

five themes; experience with innovations in general, considerations to apply innovations, current

knowledge level, perceived contribution to sustainability, and expected implementation

viii

timeframe. The results showed that the respondents are well aware of the technical innovations

and expect application in the near future. However, in general their experience with innovations

is low. Most respondents that had a high knowledge level of a specific innovation had not been

recently involved in projects in which this innovation was applied. Moreover, the respondents

have a moderate appreciation of the potential contribution of these technologies to sustainable

urban water management.

In this research, the following recommendations were made to decrease vulnerability of cities and

make better use of the urban water management technologies to do so. The first

recommendation was that cities start to build experience with using local water resources and

local flood control solution in addition to centralised systems. They should move towards a

portfolio of resources to decrease the dependency on large scale infrastructure and external

resources. The second recommendation is to increase the adaptability of urban water

infrastructure. The third recommendation is that urban water management policy makers include

long term envisioning with multiple stakeholders as a standard component of urban water

management policy to increase awareness of long term problems. The fourth recommendation is

that policy makers adjust change policy according to the full receptivity continuum of the

stakeholders that are expected to implement these changes. The advice is not to make better

policy documents, but to work on better implementation of policy by taking into account the

receptivity of the organisations that will have to implement it. The fifth recommendation is the

creation of supportive institutional frameworks and legal incentives. This includes creating of

legal space for organisations to execute tasks that indirectly contribute to the mission of the

organisation yet do not directly fit within their responsibility. The last recommendation is to

create a commercial market for urban water management innovations. These recommendations

can contribute to better implementation and mainstreaming of urban water management

innovations in order to reduce the vulnerability of cities.

ix

Samenvatting

Innovaties in het waterbeheer om de kwetsbaarheid van steden te verminderen

1

Hoe kan het stedelijk watersysteem worden ingezet om de kwetsbaarheid van steden terug te

brengen, onder andere door beter gebruik te maken van lokale bronnen? Vier jaar geleden stelden

we dit vast als belangrijke vraag van het onderzoek ‘Transities naar een duurzamer stedelijk

waterbeheer.’ Nederlandse steden kiezen regelmatig voor weinig veerkrachtige maatregelen in het

watersysteem waarbij de focus ligt op de korte of middellange termijn. De meeste maatregelen

vallen onder de optimalisatie van het bestaande systeem door efficiency verbetering. Deze

strategie lijkt overzichtelijk en rationeel, maar juist door te kiezen voor deze strategie maken

steden zich kwetsbaar, omdat toekomstige veranderingen in klimaat, landgebruik en technologie

niet vast maar dynamisch en onzeker zijn. Daarnaast onttrekken steden steeds meer grondstoffen

aan hun omgeving. Ze zijn volledig afhankelijk geworden van hun omgeving en maken zich

daardoor nog kwetsbaarder voor verstoring en verandering in diezelfde omgeving. Daarom is

gezocht naar lokale concepten van waterhuishouding en watervoorziening waardoor een stad

meer robuust en veerkrachtig wordt. Naast de technische aspecten van die nieuwe concepten is

onderzocht welke factoren bepalen of organisaties zoals een gemeente of een waterschap

haalbare innovaties ook daadwerkelijk gaan toepassen. Daartoe is de ontvankelijkheid van

waterbeheerders voor verandering in beeld gebracht.

Verminderen van kwetsbaarheid

De kwetsbaarheid van een stad wordt niet alleen bepaald door het vermogen van de beheerder

om schade door bijvoorbeeld droogte en wateroverlast te voorkomen. Ook het vermogen om

schade te beperken en te herstellen zijn van belang. Uiteindelijk wordt de kwetsbaarheid van

steden voor droogte en wateroverlast bepaald door vier capaciteiten.

 Structurele capaciteit: het vermogen om schade te voorkomen

 Schadereductie capaciteit: het vermogen om schade te reduceren als het misgaat

 Herstel capaciteit: het vermogen om het systeem weer op orde te krijgen

 Adaptieve capaciteit: het vermogen om in te spelen op onzekere ontwikkelingen zoals

klimaatverandering

De kwetsbaarheid van een stad voor toekomstige droogte kan worden verlaagd door gebruik te

maken van lokale bronnen van water in steden zoals regenwater, effluent, en oppervlaktewater

naast de traditionele centrale watervoorziening, zodat steden tijdens droogte niet louter

afhankelijk zijn van één bron. Het vermogen om droogteschade te reduceren neemt daarmee toe.

Een andere manier om de kwetsbaarheid van een stad te verlagen is een klimaatrobuuste

inrichting van de bebouwde omgeving. Dit reduceert de schade tijdens wateroverlast. Dit is van

groot belang, gezien het gegeven dat droogte en wateroverlast vanwege klimaatverandering vaker

voor zullen komen. Drie innovatieve concepten zijn in het kader van deze studie uitgewerkt.

1

This summary is based on the following publication: De Graaf, R.E., R. Dahm, F.H.M. van de Ven, en W. Dassen

(2009) Innovatief waterbeheer vermindert stedelijke kwetsbaarheid. Accepted for publication in H2O

x

Stedelijk water als energiebron

Een voorbeeld van een nieuw concept waarbij gebruik wordt gemaakt van lokale bronnen, is het

gebruik van het stedelijk watersysteem als energieleverancier. In de wijk De Draai te

Heerhugowaard is het concept uitgewerkt en getoetst voor circa 2800 woningen. In de

zomermaanden onttrekken pompen warmte aan het oppervlaktewater en slaan dit, met behulp

van warmte koude opslag (WKO), op in de bodem. In de winter kan deze warmte gebruikt

worden voor verwarming van woningen en andere gebouwen. De resultaten geven aan dat de

CO

2

uitstoot met 60% afneemt ten opzichte van een conventioneel systeem met van CV ketels.

Met een terugverdientijd van 10 jaar is het concept economisch rendabel. Men is niet langer

afhankelijk van energietransport, omdat omgevingswarmte in plaats van aardgas wordt gebruikt

voor de verwarming van woningen. Hiermee zet een gemeente een stap richting een CO

2

neutrale

en minder afhankelijke energievoorziening. Door de diversificatie van energiebronnen versterkt

de structurele capaciteit en vermindert de kwetsbaarheid. Daarnaast treedt in de zomer een

beperkte afkoeling van het oppervlaktewater systeem op waardoor de verwachte

temperatuurstijging van het water en van de stad ten gevolge van klimaatverandering wordt

verminderd. Het afkoelen van het oppervlaktewatersysteem heeft bovendien een positief effect

op de waterkwaliteit.

Stedelijk water als bron voor watervoorziening

Voor dezelfde wijk in Heerhugowaard is de haalbaarheid van een volledig zelfvoorzienend

watersysteem onderzocht; inclusief water voor de drinkwatervoorziening. In een droog jaar zoals

2003, bedraagt de jaarlijkse aanvoer die van buiten de wijk komt minder dan 5% (53.000 m

3

of 34

mm). Analyse van de waterkwaliteit en de voorgestelde zuiveringstechnologie laten zien dat het

technisch haalbaar is om drinkwater te produceren uit lokaal oppervlaktewater. De te verwachten

kosten zijn aanzienlijk hoger dan bij conventionele watervoorziening. Ook het gebruik van

regenwater om de drinkwatervraag te reduceren is onderzocht. De reductie in watervraag kan

oplopen tot 27% als alle woningen van regenwatertanks worden voorzien. De besparing in

kosten is beperkt namelijk € 118,- per jaar per huishouden door een lager drinkwater gebruik.

Indien ook de rioolheffing en zuiveringsheffing afhankelijk zou worden gemaakt van het

waterverbruik dan valt de besparing hoger uit. Het gebruik van lokale waterbronnen maakt steden

minder afhankelijk van een enkele externe waterbron. Deze diversificatie van bronnen levert ook

een bijdrage aan het vermogen van steden om zich aan te passen aan mogelijke toekomstige

droogtes.

Stedelijk water als woonplek

Het derde innovatieve concept is het gebruik van stedelijk oppervlaktewater als plaats voor

verstedelijking. In stedelijke gebieden neemt oppervlaktewater steeds meer ruimte om te voldoen

aan het Nationaal Bestuursakkoord Water. De doelstelling van extra waterberging is het

voorkomen van wateroverlast en inspelen op de mogelijke effecten van klimaatverandering. Door

de aanleg van grote percentages oppervlaktewater in nieuwbouwwijken komt de

gebiedsexploitatie onder druk te staan. Meervoudig ruimtegebruik door drijvend bouwen of

bouwen boven water biedt hier een oplossing. Tegelijkertijd is drijvende bebouwing een flexibele

en adaptieve manier van bouwen die kansen biedt om wensen van bewoners in de

gebiedsontwikkeling mee te nemen.

xi

Lessen uit het buitenland

Om onze steden minder kwetsbaar te maken voor de effecten van klimaatverandering, is het

nuttig te kijken naar landen die nu al te maken hebben met een extreem klimaat zoals Japan en

Australië. In Japan heeft men vanwege de extreme geografische omstandigheden ingezien dat

schade niet altijd te voorkomen is. Daarom heeft men geïnvesteerd in stedelijk waterbeheer

innovaties die de schade reduceren en het herstelvermogen vergroten. Voorbeelden zijn

overstromingsbestendige gebouwen, superdijken en een groot verschil tussen straatpeil en

vloerpeil. Hierdoor is waterberging in het stedelijk gebied mogelijk ondanks ruimtegebrek.

Aangepast waterbeheer vermindert op deze manier de kwetsbaarheid van het stedelijk gebied. In

Australië hanteert men een portfolio-aanpak bij het gebruik van lokale stedelijke waterbronnen.

Door een grote diversiteit aan waterbronnen, zoals effluent, regenwater, grijswater en grondwater

vergroot men de flexibiliteit om in te spelen op klimaatverandering. Australië besteedt daarmee

aandacht aan structurele capaciteit, schade reductie capaciteit, herstelcapaciteit en adaptieve

capaciteit. Zo zien we dat in het buitenland innovatieve concepten voor het waterbeheer de

kwetsbaarheid van de stad verminderen.

Van kennis naar praktijk

Wat bepaalt nu of deze innovaties in de praktijk van het stedelijk waterbeheer toegepast worden?

Het blijkt dat de keuze om over te gaan tot het toepassen van een innovatie sterk wordt bepaald

door twee voorwaarden waaraan moet worden voldaan. Allereerst dient de innovatie opgepakt te

worden in het proces van ruimtelijke ontwikkeling. Daarnaast is van belang dat waterbeheerders

openstaan voor de innovatie, kansen zien voor hun eigen organisatie, en de benodigde kennis en

vaardigheden hebben. Voor de eerste voorwaarde is het van groot belang dat waterbeheerders

samenwerken met ruimtelijke ordenaars en stedenbouwkundigen. Een studie naar ‘Rotterdam

Waterstad 2035’ laat zien dat samenwerking tussen deze disciplines kan leiden tot een omslag in

het denken waar beide partijen overtuigd zijn van het nut van samenwerking. Waterberging wordt

beter gerealiseerd door inpassing in het proces van stedelijke vernieuwing. Daarnaast biedt water

kansen om een stad aantrekkelijker te maken voor bewoners en bedrijven. Een goede manier om

de samenwerking op gang te brengen is het starten van een lange termijn visievormingsproces. In

Rotterdam was het hierdoor mogelijk innovatieve ideeën te genereren voor een lange tijdshorizon.

Toen meerdere organisaties hun enthousiasme uitten over deze visie, werden ideeën zoals groene

daken, waterpleinen en drijvende gebouwen uit deze visie opgenomen in het officiële waterplan.

Door de koppeling met stedelijke vernieuwing en klimaatadaptatie kwam het thema ‘water’ hoger

op de politieke agenda.

De tweede voorwaarde die bepaalt of technisch haalbare innovaties in de praktijk worden

toegepast is de mate waarin waterbeheerders openstaan voor deze innovaties. Om deze

bereidheid te meten werd een landelijke enquête gehouden onder stedelijk waterbeheerders van

zowel waterschappen als gemeenten. De resultaten van deze enquête laten zien dat de

respondenten goed op de hoogte zijn van de drie eerder beschreven innovaties. Bovendien

verwachten zij dat deze innovaties in de nabije toekomst worden toegepast in het beheersgebied

waar zij werkzaam zijn. Het blijkt echter dat weinig respondenten persoonlijk ervaring hebben

opgedaan met een van deze innovaties. Bovendien schatten zij de positieve bijdrage van

bovenstaande innovaties aan duurzaam stedelijk waterbeheer als matig tot redelijk.

Wat betekent dit? Dat ervaringskennis met een innovatie voor een waterbeheerder niet als

strikt noodzakelijk wordt gezien om toch innovatieve concepten toe te passen. Men verwacht dat

innovaties worden toegepast maar tegelijkertijd verwacht men ook dat dit maar een beperkte

xii

bijdrage zal leveren aan het bereiken aan duurzaam waterbeheer. Nieuwe concepten worden

kleinschalig in demonstratieprojecten toegepast maar blijven vrij geïsoleerd in hun invloed op het

overkoepelende systeem. Voor een betere doorwerking van kennis naar praktijk is het daarom

van belang om meer aandacht te besteden aan de kennisdoelen en leerdoelen van

demonstratieprojecten in plaats van de technische demonstratie zelf. Innovaties zullen uiteindelijk

moeten worden herhaald en opgeschaald willen zij doorbreken in de algemene praktijk van het

stedelijk waterbeheer. Het is daarom van belang dat stedelijk waterbeheerders aandacht geven aan

draagvlak en innovatieve projecten blijven herhalen en tegelijk verbeteren.

Aanbevelingen

Om de kwetsbaarheid van onze steden te verminderen zijn op basis van het uitgevoerde

onderzoek een aantal aanbevelingen geformuleerd:

 Bouw ervaring op met lokale concepten van watervoorziening en waterrobuuste

verstedelijking door middel van demonstratieprojecten. Hierdoor neemt het aantal

beschikbare opties om in te spelen op de toekomst toe, en daarmee het adaptieve

vermogen.

 Verhoog de adaptiviteit van stedelijk watersystemen door te bouwen voor een kortere

levensduur of kies bewust voor redundantie. Hierdoor wordt het eenvoudiger in te spelen

op onzekere toekomstige ontwikkelingen. Alleen als men de toekomst kent, bouwt men

voor de eeuwigheid.

 Neem lange termijn visievorming op als standaard onderdeel in het stedelijk waterbeleid.

Hierdoor neemt het bewustzijn voor lange termijn problemen als droogte, bodemdaling,

klimaatverandering en demografische ontwikkelingen toe. Het biedt de mogelijkheid om

interdisciplinair samen te werken en buiten gebaande paden te denken.

 Neem de bereidheid van waterbeheerders om innovaties toe te passen integraal mee bij

het ontwikkelen van waterbeleid. De waterbeheerders moeten overtuigd zijn dat een

andere manier van werken voordelen biedt voor hun organisatie. Creëer statutaire en

juridische ruimte voor organisaties om te participeren in multifunctionele watersystemen

en innovaties. Het toepassen van innovaties betekent vaak dat belanghebbenden nieuwe

rollen gaan vervullen. Zo kan een waterschap betrokken raken bij de aanleg en

onderhoud van groene daken, bij de commerciële uitgifte van waterkavels of bij

concessies voor warmtewinning.

 Stimuleer de ontwikkeling van een commerciële markt voor stedelijk waterbeheer

innovaties. Innovaties in het stedelijk waterbeheer zullen pas doorbreken als zij worden

opgepakt door bouwers en projectontwikkelaars. Daarom is het van belang dat

marktwerking ontstaat voor deze innovaties. Het faciliteren van maatschappelijke en

economische stimulansen, zoals strengere normen, het uitreiken van prijzen en

bewustwording bij burgers kan dit proces versnellen.

Contents

Summary .................................................................................................................................v

Samenvatting......................................................................................................................... ix

1 Introduction ....................................................................................................................1

1.1

Background ........................................................................................................................................................................ 1

1.2

Research questions..........................................................................................................................................................10

1.3

Research context .............................................................................................................................................................12

1.4

Research methods ...........................................................................................................................................................12

1.5

Thesis structure ...............................................................................................................................................................16

PART 1: Urban water management innovations to reduce vulnerability of urban areas .... 19

2 Four components of vulnerability: theory and application .......................................... 21

2.1

Introduction ..................................................................................................................................................................... 21

2.2

Four components of vulnerability................................................................................................................................ 21

2.3

The Netherlands: vulnerability of flood defence........................................................................................................ 26

2.4

The Netherlands: vulnerability of water supply.......................................................................................................... 27

2.5

Towards reduced vulnerability ...................................................................................................................................... 30

2.6

Conclusion........................................................................................................................................................................ 34

3 Stormwater management and multi source water supply in Japan: Innovative

approaches to reduce vulnerability.......................................................................................37

3.1

Introduction ..................................................................................................................................................................... 37

3.2

Four components to reduce vulnerability to flooding............................................................................................... 38

3.3

Four components to reduce vulnerability of water supply....................................................................................... 43

3.4

Comparison between Japan and the Netherlands...................................................................................................... 48

3.5

Conclusion........................................................................................................................................................................ 49

4 Case study Heerhugowaard, use of local water resources............................................ 51

4.1

Introduction ..................................................................................................................................................................... 51

4.2

Methodology .................................................................................................................................................................... 54

4.3

Feasibility local water production................................................................................................................................. 57

xiv

4.4

Feasibility rainwater harvesting..................................................................................................................................... 62

4.5

Analysis ............................................................................................................................................................................. 63

4.6

Conclusion........................................................................................................................................................................ 65

5 Case study Heerhugowaard, use of the local urban water system as energy source ...67

5.1

Introduction ..................................................................................................................................................................... 67

5.2

Methodology .................................................................................................................................................................... 70

5.3

Results ............................................................................................................................................................................... 78

5.4

Analysis ............................................................................................................................................................................. 82

5.5

Conclusion........................................................................................................................................................................ 84

6 Case study Netherlands: Using the surface water for urbanisation .............................85

6.1

Introduction ..................................................................................................................................................................... 85

6.2

Living on water, a niche market.................................................................................................................................... 86

6.3

Mainstreaming of floating urbanisation.......................................................................................................................86

6.4

Floating Utility Units, the step to floating cities......................................................................................................... 94

6.5

Analysis ............................................................................................................................................................................. 96

6.6

Conclusion........................................................................................................................................................................ 98

PART 2: Mainstreaming of urban water management innovations ....................................99

7 Mainstreaming of urban water management innovations, contributions from social

theory................................................................................................................................... 101

7.1

Introduction................................................................................................................................................................... 101

7.2

Large technical systems ................................................................................................................................................ 104

7.3

Multilevel perspective...................................................................................................................................................104

7.4

Transition theory...........................................................................................................................................................107

7.5

Receptivity continuum..................................................................................................................................................110

7.6

Mainstreaming urban water innovations: examples from literature...................................................................... 111

7.7

Synthesis .........................................................................................................................................................................115

8 Case study Rotterdam: linking water management and urban renewal .................... 119

8.1

Introduction................................................................................................................................................................... 119

8.2

Case study background.................................................................................................................................................119

8.3

Methodology..................................................................................................................................................................122

8.4

Results.............................................................................................................................................................................123

xv

8.5

Discussion ......................................................................................................................................................................128

8.6

Conclusion......................................................................................................................................................................130

9 Receptivity to transformative change in the Dutch urban water management sector

..................................................................................................................................... 131

9.1

Introduction................................................................................................................................................................... 131

9.2

Methodology..................................................................................................................................................................131

9.3

Results.............................................................................................................................................................................134

9.4

Discussion ......................................................................................................................................................................138

9.5

Conclusion......................................................................................................................................................................139

10 Perspectives on innovation: a survey of the Dutch urban water management sector 141

10.1

Introduction................................................................................................................................................................... 141

10.2

Methodology..................................................................................................................................................................141

10.3

Results.............................................................................................................................................................................143

10.4

Discussion ......................................................................................................................................................................149

10.5

Conclusion......................................................................................................................................................................151

11 Discussion and conclusions for mainstreaming of urban water management

innovations to reduce vulnerability .................................................................................... 153

11.1

Introduction................................................................................................................................................................... 153

11.2

Vulnerability...................................................................................................................................................................153

11.3

Innovations in urban water management to reduce vulnerability .........................................................................155

11.4

Mainstreaming of urban water management innovations....................................................................................... 159

11.5

Reflection and general recommendations .................................................................................................................165

11.6

Integrative research approach and impact on practice............................................................................................168

11.7

Recommendations for future work............................................................................................................................ 168

References........................................................................................................................... 171

Appendix ............................................................................................................................. 181

Acknowledgements............................................................................................................. 183

Curriculum Vitae................................................................................................................. 185

Publications ........................................................................................................................ 186

1 Introduction

1.1 Background

1.1.1 Urban water systems

Urban water systems consist of five interrelated types of water in urban areas: groundwater,

surface water, stormwater, drinking water and wastewater (Van de Ven, 2006a). Urban water

management is defined as the management of quantity and quality of stormwater, groundwater

and surface water in urban areas. This area is the lower part in figure 1.1 that is called the

‘watersystem’. It is the study area of urban water management engineers. It is also the focus area

of this thesis that describes urban water management innovations to reduce vulnerability of cities.

Innovations are defined as technologies that enable using the urban water system for new

functions. The upper part is the ‘water chain’ which includes drinking water supply, sewer

systems and wastewater treatment. This is the study area of sanitary engineers. Urban water

systems have two sources of water: precipitation and external drinking water supply through

pipes.

Figure 1.1 Schematisation of the urban water system (combined sewer system)

Rainwater is converted to stormwater when it falls on paved and unpaved surfaces. In the

Netherlands, predominantly combined sewer systems have been implemented in the past, this is

the system that is shown in figure 1.1. In these systems, stormwater is transported with

wastewater in the same pipe. During heavy rainstorms the capacity of the sewer system is not

sufficient to transport all runoff. In that case, combined sewer overflows (CSO’s) take place. This

leads to the emission of diluted wastewater and sewage sludge to the urban surface water. In

2 Chapter 1. Introduction

Dutch national policy, it is now generally accepted that relatively clean stormwater should not be

mixed with wastewater flows (e.g. VROM, 2003; VROM 2006).

Separate sewer systems were implemented in the Netherlands from the 1970’s.

Disconnection of paved surfaces from the combined system, and infiltration of stormwater has

been widely adopted by municipalities in the Netherlands since the end of the 1980’s.

1.1.2 History of urban water systems

Based on the work of Van der Ham (2002), Hooimeijer (2008) describes the following phases in

the development and design of polder cities in the Netherlands. In particular, the relation of cities

with the regional water system is described. In order to make the marshlands suitable for

urbanisation, it was crucial to manage surface water and groundwater levels artificially. The

phases below can be considered as the development of the Dutch approach to urban water

management in polder cities.

1. Acceptation (until 1000)

2. Defensive (1000-1500)

3. Offensive (1500-1800)

4. Early manipulative (1800-1890),

5. Manipulative (1890-1990)

6. Adaptive manipulative (1990-today).

The six phases describe a growing influence of technology over the natural water system. There is

a gradual change from adapting settlements to the water system (first phase) to the construction

of the first dikes and sluices (second phase) and the reclamation of polders (third and fourth

phases). The fifth phase is characterised by the separation of the professions of civil engineering

and urban design. In this phase, polder areas were integrally raised with sand to make them

suitable for urbanisation, water levels were controlled by pumping stations. Consequently, urban

designers were provided a clean sheet for urban expansion plans. All water problems could be

solved by civil engineers (Hooimeijer, 2008). As a result, water aspects were no longer

incorporated in the urban design. The last phase is characterised by an approach in which cities

have to adapt more to the natural system instead of manipulating it. This is caused by the rise of

environmental awareness in the 1970’s and climate change problems in 1990’s. As a result, more

water storage is constructed in urban areas and the link between water management and urban

planning has become more important again. In the Netherlands, there has been a change in

perception on water management. Van der Brugge et al. (2005) described how over the past

decades, water management approach has changed from a technical approach to a more

integrative approach.

Brown et al. (2008) described six distinct, cumulative transition states in the development of

urban water management in Australia. These phases also include the development of water

supply. The same pattern can be found in other Western countries. These phases roughly

correspond to the phases 4 to 6 the Hooimeijer framework.

Water supply city

Industrialisation and rapid urbanisation caused severe public health problems and water shortage

by the middle of 19

th

century. In the Netherlands, this created room for the first piped water

supply in the 1850’s (Geels, 2005). However, Geels also describes that for diffusion of this

technology several political and cultural developments were instrumental. The required

3

investment threshold was exceeded by further urbanisation and economic growth. This resulted

in sufficient mass of people that were willing and able to pay for piped drinking water from

public taps or a private connection.

In addition, development of hygiene and health sciences provided important insights in the

relation between polluted drinking water and epidemics. The work of Snow (1849) who

discovered a connection between the cholera epidemic and the use of polluted drinking water in

the city of London, contributed to the increased importance of hygienic issues in society. In the

Netherlands, cleanliness became an important norm for the middle classes in the 1860’s and

1870’s. The rise of workers unions and further expansion of voting rights provided strong

incentives for politicians to deal with the public health problems.

Sewered city

The first sewers consisted of gutters that were constructed for stormwater drainage. Societal

concerns about public health, criticism from hygienic doctors and engineers, rapid urbanisation,

changes in legislation and normative and behavioural changes contributed to the diffusion of

sewer systems by the beginning of the 20

th

century (Geels, 2006). The Netherlands was relatively

late with the implementation of sewer systems. The Hague constructed the first sewer system in

1893, Amsterdam in 1913.

Drainage city

The post-war reconstruction period was characterised by rapid economic growth and

urbanisation. The car became a common method for transportation. As a result, there was a huge

increase of paved surfaces that generated stormwater. Stormwater was transported away from

urban areas as quickly as possible by combined sewer systems. New urban expansions were

integrally raised with sand. The amount of surface water in these developments was limited.

Waterway city

Environmental concern in the 1970’s led to a growing influence of ecologists in water

management (Van der Brugge et al., 2005). Environmental protection became an important issue.

Wastewater treatment plants were constructed to improve water quality and to protect ecology in

receiving waterways. Separated sewer systems were constructed to improve water quality. In the

1980’s, diffuse pollution and source control of pollutants instead of an end-of-pipe approach,

emerged as an important theme in urban water management (e.g. TNO-CHO, 1985; NWRW,

1989). Because source control deals with distributed pollution, the connection with spatial

planning became more important.

Watercycle city

Since the 1990’s, there has been a rising importance of the concept of sustainability. Concerns

about the limits of water resources became drivers for water conservation and water recycling. In

Utrecht, the Netherlands, a third pipe network feasibility study was done for the Leidsche Rijn

urban expansion in 1994 (Rijke, 2007) and for IJburg in Amsterdam in 1997 (Van der Hoek et al.,

1997). The main purpose was not to use purified drinking water for the transportation of waste.

A misconnection between the third pipe system and the drinking water system stopped this

development in the Netherlands. According to Brown et al. (2008) the watercycle city has not yet

been implemented as mainstream practice in any city. It is still limited to academic discussions

and small scale demonstration projects.

4 Chapter 1. Introduction

Water Sensitive City

The Water Sensitive City is a potential future state of urban water systems. The main drivers are

intergenerational equity and climate change. It will be further discussed in this chapter in the

section about future water systems.

1.1.3 Criticism on current urban water systems

Current urban water systems are criticised by many scholars for their inherent unsustainability.

The construction of centralised water infrastructure in the 19

th

and 20

th

century has successfully

tackled most public health problems, part of urban flooding problems, and localised

environmental problems (Butler and Parkinson, 1997). Predominantly centralised large scale

‘hard’ infrastructures were constructed for instance dams, concrete embankments, sewers, and

water supply networks. These systems brought huge benefits for society. However they also had

serious ecological, social and economic costs (Gleick, 2003). Negative aspects of the current

urban water system include: effects of urban runoff on aquatic ecosystems, the lack of recycling

of nutrients, the use of purified water to transport waste, land subsidence, high investments and

maintenance costs, and the lack of flexibility to cope with future challenges. Cities show parasitic

behaviour (De Graaf and Van de Ven, 2006). They extract all required resources from the

surrounding area and after using them, discharge the pollutants to this area. Cities hardly use

internal resources of water, energy and nutrients and require more and more space.

Stormwater impacts on ecosystems

Centralised systems for transportation and collection of stormwater were implemented to drain

stormwater runoff out of the urban area as quickly as possible. It has been generally

acknowledged that the conventional way of dealing with stormwater in combination with rapid

urbanisation, leads to significant adverse hydrological and ecological changes (Rivard et al., 2005).

Even at low levels of urban development, the discharge of urban runoff by centralised

collection and transportation systems has detrimental effects on aquatic ecosystems (Booth and

Jackson, 1997). Reported effects on receiving waters include: flooding, erosion, sedimentation,

temperature rise, dissolved oxygen depletion, eutrophication, toxicity, and reduced biodiversity

(Marsalek, 1998). A negative exponential relationship between the expansion of paved surface

area and receiving water quality has been observed (Ellis, 2008).

In the Netherlands the situation is different because the water quality in the rural

surroundings is often worse than the stormwater quality from separated sewer systems in urban

areas. This is due to the intensive agriculture and the excessive use of fertilisers.

Newman and Mouritz (1996) link the problem of urban runoff to the increase of car mobility

and the construction of cities that depend on car based mobility for their functioning. This has

led to large areas of sealed surfaces. They state that stormwater from bitumen based cities is

excessive in quantity and quality.

Nutrient management

The linear nature of centralised urban water infrastructure leads to flows of nutrients, chemicals

and substances that can accumulate in aquatic ecosystems (Butler and Parkinson, 1997). The

absence of closed cycles will lead to a lack of nutrients in some places and accumulation in others

(Berndtsson and Hyvönen, 2002). Therefore, provision of sanitation should be combined with

the developments of methods and technologies that enable recycling of nutrients from

wastewater to agriculture (Niemczynowicz, 1999).

5

Rock phosphate is a finite resource and should therefore be recycled instead of being

disposed to landfills, or discharged to the aquatic environment where it accumulates in sediments.

Proven phosphate reserves are sufficient for 100 years of economic use (Driver et al., 1999;

Isherwood, 2000). According to some authors, decentralised local systems should be

implemented for this purpose (Otterpohl et al., 1997; Zeeman and Lettinga, 1999). However,

technologies are currently available and are being developed for phosphate recycling from

wastewater that could also be applied in centralised systems (de-Bashan and Bashan; 2004).

Nitrogen is available in large quantities in the atmosphere. It is used to produce artificial

fertilisers through ammonia synthesis (Haber Bosch process). Biological nitrogen removal and

ammonia synthesis can be regarded as nitrogen recovery via the atmosphere (Wilsenach, 2006:

33). Industrial ammonia synthesis is vital for global food production to sustain the current size of

human population. However, it has led to radical changes in the environment, including water

and air pollution and a loss of biodiversity due to a huge increase in ammonia production

(Erisman et al., 2008).

Water efficiency

Cities extract their water supply almost entirely from surrounding areas. Local water resources are

hardly used. Water flow to cities is therefore an example of a linear flow. Although the urban

water cycle is part of the hydrological cycle at a higher scale, water depletion of groundwater

resources and the absence of using local water resources cause linear flow patterns at the city

scale. Current urban water systems use purified water to transport waste. According to Butler and

Parkinson (1997) conventional drainage systems use water extremely inefficiently. They regard

this as the waste of a precious resource and unnecessary dilution of waste that requires end-of-

pipe technology to extract solid waste components from the diluted wastewater stream.

Use of local water resources or water recycling could contribute to more cyclic water flows

through the urban environment, and decrease impacts of cities on the surrounding areas. In the

Netherlands 93,000 ha of nature area suffers from groundwater depletion (Vewin, 2004). In many

cities groundwater resources are threatened due to overexploitation (Niemczynowicz, 1999).

Land subsidence

Urban groundwater management and soft soils lead to land subsidence in many urbanised delta

areas. Examples of serious problems due to land subsidence are increased inundation frequency,

increased flood impacts, salt water intrusion and groundwater nuisance. Groundwater

overexploitation and groundwater drainage cause increase pore pressure and reduce pore space in

compactable soils. This results in land subsidence.

Holzer and Johnson (1985) described 8 cities that suffered significant economic damage due

to land subsidence. The cities were: Bangkok, Houston, Mexico City, Osaka, San Jose, Shanghai,

Tokyo, and Venice. Continuing urbanisation of delta areas has increased the potential damage.

Wei (2006) found that in Shanghai the direct economical loss caused by land subsidence was €

1.45 billion and the indirect economical lost is € 28 billion Euros in the period 1949-2000.

In the lowland areas in the Netherlands, soil compaction and oxidation of peat soils have

resulted in land subsidence up to 5 cm per year (Van der Meulen et al., 2007). To reduce

groundwater nuisance and maintain an unsaturated zone in the upper layer, groundwater levels

are periodically decreased. This results in continuing land subsidence that has accumulated to

several meters in certain areas. In addition, due to the protection of urban areas with dikes,

natural sedimentation processes no longer take place. This has resulted in a cumulative sediment

6 Chapter 1. Introduction

deficit which makes it impossible for urbanised deltas to keep up with sea level rise (Van der

Meulen et al., 2007).

Economic considerations

Large scale centralised urban wastewater systems are considered expensive. They are energy

intensive and require high investments. However they are also cost effective if the costs are

calculated per capita (Wilsenach, 2006). According to Ashley et al. (2007a), the continuing use of

high-energy systems will become increasingly untenable. Massive investments cause problems for

retrofitting and upgrading of densely built and populated urban areas (Kotz and Hiessl, 2005).

Rising costs are caused by aging assets and higher quality standards (Barraqué, 2003).

Large water systems develop economies of scale but often lose the ability to provide small

scale services and miss opportunities for local efficiencies. (Newman and Mouritz, 1996). In the

Netherlands, the replacement value of the sewer system is € 62 billion (Rioned, 2009). Annual

expenditure for operation and maintenance of the sewer system (wastewater treatment not

included) is € 1,081 million or € 66 per capita. Although this may be relatively low compared to

other public infrastructure, the annual costs for urban drainage in the Netherlands has risen 5%

every year on average between 1990 and 2003 and is expected to rise further due to ageing of

infrastructure and increasing societal demands (Hoeben and Gerritsen, 2005).

Lack of sustainability

According to many researchers urban water infrastructures should be structurally transformed

because they are unsustainable in particular with regard to nutrient recycling and water efficiency

(e.g. Otterpohl et al., 1997). The widely used definition of sustainable development from the

Brundtland Report (WCED, 1987) is that ‘sustainable development is meeting the needs of

current generations without compromising the ability of future generations to meet their needs’.

Definitions that are used in urban water management describe sustainability as a balance

between social, economic and ecological values. A sustainable approach should include sufficient

flexibility in the system to accommodate future changes (Berndtsson and Jinno, 2008).

The concept of sustainability, however, still lacks consensus about the exact meaning. As

addressed by Rijsberman and Van de Ven (2000) the interpretation of what is sustainable

depends on personal values and perceptions of participants in a debate. Some define

sustainability as economic efficiency whereas others are more focused on retaining the integrity

of ecosystems. Butler and Parkinson (1997) state that sustainability is likely to remain ambiguous

and without absolute definition.

Lack of flexibility

There are many drivers for the urban water system to change. Ashley et al. (2007a) mention three

most important drivers for sewer systems: (1) environmental legislation, public attitudes and

expectations, (2) land use and urbanisation and (3) energy and resource stress. Other drivers that

are documented in literature are: privatised ownership of water infrastructure, new pollutants

risks, new technologies, demographic developments, and the lack of sustainability of current

systems (Lienert et al., 2006).

Climate change is more and more mentioned as a major driver for changing urban water

systems (Ashley et al., 2007b). However, changing current urban water systems is difficult

because they have life spans of decades and are characterised by considerable sunk cost (Hiessl et

al. 2001). Pahl-Wostl (2005) suggests that the longevity of current water infrastructure and

7

management practices is insufficient to deal with fast changes and uncertainty. In case of

uncertainty and recognised ignorance in predicting the consequences of technological

development on complex natural systems, solutions have to be flexible. Irreversibility of

consequences should be prevented (Harremoës, 2003).

The high technical lifetime of 50-100 years make urban water systems inflexible to adapt to

future changes such as climate change (Kotz and Hiessl, 2005). Time horizons in urban water

management are generally short, often five-year planning cycles (Ashley et al., 2007a). There is a

clear mismatch between the planning horizon and the technical lifetime. The planning horizon

does not go beyond the expected lifetime of the infrastructure, therefore only optimizing

measures can be proposed in planning documents, unless the current infrastructure is demolished

and replaced by a new system. This is a limitation on the adaptive potential of urban water

infrastructure to uncertain effects of climate change and societal changes.

Institutional fragmentation and specialisation

Institutional fragmentation has resulted in functional silos in which part of the system is

optimised in isolation of other system components (Wong, 2006a). This has led to a suboptimal

overall system performance. Technical optimisation of a component of a large technical system

may prevent system innovation. Moreover, it may lead to a technical and institutional lock in.

Different organisations are responsible for the interrelated components of urban water systems.

Fragmented accountability frameworks of urban water organisations leave limited room for

action that diverges from statutory responsibilities. Institutional objectives of urban water

management organisations are focused on performing prescribed task within legal frameworks.

There is no defined responsibility for the overall urban water system. Reward mechanisms are

based on fulfilling procedures, within the boundaries of projected costs and projected timeframes.

Therefore, there are significant obstacles to fulfil roles that are different from the traditional role.

However, the fulfilling of other roles is central to innovations in urban water management. This

will be further elaborated in part 2 of this thesis.

The role of the specialist has co-evolved with institutional fragmentation of the water system.

Harremoës (2002) argued that experts have to become highly specialised in order to receive

recognition. This leads to a narrow interpretation of urban water issues and the use of expert

terminology that makes cooperation between disciplines difficult. Saul (1992) described that

experts in general are increasingly in a contradictory position. On one hand the expert has a rising

autonomy in tiny slice of expertise. On the other hand, the expert is getting increasingly locked in

a separated area of expertise, and is becoming increasingly powerless in society as a whole.

Fragmented urban development process

Next to institutional fragmentation, also the urban planning process itself is fragmented. As

observed by Geldof (2005), western organisations often apply the serial planning approach. This

approach is characterised by fragmentation of the urban development process in distinct steps of

policy, planning, design, construction and maintenance. For each step, different stakeholders are

responsible that are not involved in previous phases or follow up phases. The result is that

communication between the phases takes place in the form of reports, documents and guidelines.

Only transfer of explicit knowledge is possible and other forms of knowledge (e.g. tacit

knowledge) will not be transferred to the next phase of the process. Original intentions of the

policy are lost in the design phase when feasible measures are desired.

8 Chapter 1. Introduction

Lack of citizen involvement

Although urban water institutions increasingly use the term client, there is usually no freedom of

choice for citizens to buy services other than those provided by centralised water infrastructure.

Citizen involvement in urban water management that goes further than paying taxes and fees is

rare. Professionals in specialised institutions are reassuring in the fact that they provide high level

knowledge and will take care of the citizens’ problems. According to Pahl-Wostl (2005), the lack

of information and insufficient ability prevent citizens from meaningful participation in decision

making processes with regard to current and future functioning of urban water systems.

Involving the private sector is also problematic. Market mechanisms to successfully support

innovation in urban water management are lacking and there are huge barriers for private sector

participation in the urban water sector (Rothenberger et al., 2005).

1.1.4 Future urban water systems

The critique on current urban water systems has resulted in a large number of publications that

outline properties and characteristics of future water systems. These systems are also expected to

make use of opportunities such as utilisation of local resources. The characteristics of future

water systems can be subdivided into categories of socio-economy, ecology, resource use and

management.

Socio-economy

According to many authors (Larsen and Gujer, 1996; Butler and Parkinson, 1997; Berndtsson

and Hyvönen, 2002) public health protection should remain a key function of urban water

systems. This may include the supply of water and the removing of faecal matter from urban

areas where it would cause disruption if it would accumulate.

Flood prevention is an important function of urban water systems. Because urban areas

create paved surfaces, urban runoff is generated that should be managed to prevent pluvial

flooding. According to Newman and Mouritz (1996), future cities should have increased soft

surfaces for stormwater retention. Also Ellis (2008) argues that ‘3

rd

generation urban drainage’

consists of the introduction of vegetative systems into the urban form to reduce surface water

runoff.

Newman and Mouritz (1996) found economic, ecological and social benefits of community

scale water management systems. Local systems often require lower initial investments than

conventional systems and contribute to the local economy by facilitating use of receiving waters,

increasing real estate value, and the development of eco-industry for the production of

environmental technologies (Marsalek and Chocat, 2002). The Deltares’ Water City (Van de Ven,

2009) provides a number of functional characteristics including: surface water as space, water as

energy source, water as soil carrier and water to improve the urban landscape.

Ecology

Urban stormwater management should aim to protect downstream aquatic systems, remove

pollutants and protect stormwater elements as a part of the urban landscape (Wong, 2006b).

Stormwater control and management near the source is promoted as a paradigm to address the

problems that were caused by conventional systems. This has led to the introduction of concepts

such as: Water Sensitive Urban Design (WSUD), Sustainable Urban Drainage Systems (SUDS),

Low Impact Development (LID), Best Management Practices (BMP’s) and Integrated Urban

Water Management (IUWM). All of these concepts are characterised by a focus on source

9

control rather than end-of-pipe treatment of stormwater. Methods to locally attenuate

stormwater include: filter strips, constructed wetlands, permeable pavements, bioretention

systems, green roofs and infiltration systems. Marsalek and Chocat (2002) provide a

comprehensive review of current technologies.

Resource use

Instead of a waste, stormwater should be considered as a valuable resource for water use

functions that do not require the highest quality (Niemczynowicz, 1999). It is estimated that

China and India will need all runoff that is generated to meet urban and agricultural water

demand in the next 20 years (Jury and Vaux, 2005). Urban demand from water supply

catchments should therefore be reduced (Wong, 2006b). Infrastructure that combines both

centralised and decentralised water sources makes cities more flexible to adapt to external

changes such as climate change. Gleick (2003) argued that community-scale, decentralised

facilities must complement conventional centralised infrastructure.

Nutrient cycles of urban water systems should be closed through recycling and drinking water

use for transportation of excreta should be abandoned (Berndtsson and Hyvönen, 2002). Some

authors have therefore proposed urban agriculture as a function of urban water management

(Larsen and Gujer, 1997; Niemczynowicz, 1999). This would allow for nutrient recycling on a

local rather than on a global scale and would decrease the dependency of urban areas on the

global system of food production.

Management

To address the problem of institutional fragmentation, an integrated and multi-disciplinary

framework is required (Butler and Parkinson, 1997). According to Niemczynowicz (1999) the

future challenges within urban water management will be to organise cross-sectoral stakeholder

cooperation in order to introduce innovative water technologies, management systems and

institutional arrangements. These systems should be able to meet the multiple objectives of equity,

environmental integrity and economic efficiency, and at the same time achieve a high level of

water services.

Rijsberman and Van de Ven (2000) demonstrated that urban water systems have to fulfil an

increasing number of functions and are influenced by various conflicting values. Urban water

management has a multi-functional and multi-stakeholder character. Stakeholders usually do not

agree about the problems, objectives, and solutions. In addition, the required means are

sometimes unknown. Thus, the connection with urban planning and development, that is the

process through which spatial functions are determined and values are negotiated, is increasingly

important.

Mouritz (1996) argues that the design of future water infrastructure should be developed by

integrated planning and management of land, water and other resources. Also Van Rooy et al.

(1998) state that water is a part of our environment and that water policies interact with urban

planning policies. In addition, each development should aim to improve the functions of natural

water system to maximise local environmental and economic benefits (Ellis, 1995).

The drivers that influence urban water systems are characterised by large margins of

uncertainty. Moreover the expected lifespan of urban water infrastructure is high, often decades.

Therefore, flexibility is considered a key required attribute of urban water systems (Butler and

Parkinson, 1997). Boundary conditions are no longer considered stable. The adaptability of

infrastructure therefore becomes a crucial attribute to adapt to changes in society and the

10 Chapter 1. Introduction

environment. According to Harremoës (2003) reliable predictions about the impact of

technologies on the complex environment are lacking. Therefore there is no justification for

irreversible decisions. According to the same author, decisions should be considered experiments

that require monitoring to continuously improve our understanding of the system.

The active participation of the users is essential if local solutions are to be adopted (Butler

and Parkinson, 1997). Pahl-Wostl (2006) listed a number of essential attributes for meaningful

citizen participation including: access to comprehensive and timely information, capacity building

and empowerment of citizens, reform of institutional settings to allow citizens to articulate their

perspective, involvement in both envisioning of future management schemes and daily

management. In addition, user fees could be made dependent on the effort made on private

property to contribute to the overall system performance (Parikh et al., 2005). Citizens may play a

more active role that the passive consumer in the provision of urban water services for instance

as a producer of local water resources (Hegger, 2007). Based on the cited literature above, the

envisaged characteristics of future water systems can be summarised as follows:

1. Socio economic

• Public health protection

• Flood control by local stormwater retention

• Multi functional use of surface water

• Water as carrier for the soil

2. Ecology

• Protection of aquatic ecosystems

• Water as carrier for the soil

3. Natural resource use

• Closed nutrient cycles by recycling

• Increased water use efficiency

• Urban water systems as source of local water, energy and food resources

• Flexible and adaptable urban water infrastructure

4. Management arrangements

• Integration of water management and land use planning

• Meaningful citizen involvement

• Flexible and adaptable management arrangements

• Cross sectoral stakeholder cooperation

1.2 Research questions

The previous section described properties of future urban water systems. The main objective of

these properties can be understood as reducing the vulnerability of cities and ecosystems. Water

related vulnerability has many aspects. For instance, the purpose of flood control is reducing

vulnerability of cities to flooding. The impact of cities on aquatic ecosystems is reduced in order

to decrease the vulnerability of these ecosystems to disruption resulting from human influence.

Closing nutrient cycles and increased water use efficiency contribute to decreasing the

vulnerability of urban areas by reducing their dependence on external resources.

One could argue that the main purpose of technology itself is to deal with variability in the

environment to reduce the vulnerability of society. The first human technological advances such

as tools, shelter and agriculture all contributed to a decreased vulnerability of human settlements

11

to sudden changes in the environment. In addition, the vulnerability concept is useful for

reflection on a topic that includes social, ecological and technical components. The continuing

functioning of these components in time can be described in terms of vulnerability. Therefore,

the framework of vulnerability is used as the theoretical basis of this thesis. It will be further

described in the next chapter.

The research was focused on surface water, stormwater and groundwater within cities. In

particular, local scale opportunities that these components of the urban water system (fig. 1.1)

offer to reduce vulnerability of water supply, energy supply and flood control in cities were

studied. Current water supply, energy supply and flood control infrastructures of cities stretch out

beyond the city scale. Therefore, chapter 2 applies the vulnerability framework on water supply

and flood control in the Netherlands on a national scale. After this step, the research focused on

local scale urban water management innovations that reduce the vulnerability of cities.

The overarching aim of this research was to develop understanding and insight how

innovations in urban water management can be realised. This requires three things: 1)

understanding of the current system, 2) knowledge of urban water management innovations and

3) knowledge how to implement these innovations in a societal context. However,

implementation of innovations does not necessarily lead to significant change in urban water

management. Innovations may remain confined to showcase demonstration projects. Therefore,

an additional research objective was to identify mechanisms that determine the adoption of

innovations in mainstream day-to-day professional practice. To address these aspects, this thesis

describes vulnerability theory to contribute to a better understanding of the current situation.

Additionally, the technical feasibility of concepts that use the urban water surface water and

urban groundwater to reduce the vulnerability of cities was studied. Finally, this research

addressed mechanisms that influence the adoption and mainstreaming of these technical

concepts. These three components led to the following research questions.

A) Vulnerability

1. What is a useful framework to understand water related vulnerability of urban

areas?

2. What can we learn from other countries in dealing with water related vulnerability?

B) Innovations in urban water management

1. How could innovations in urban water management be used to reduce

vulnerability of urban areas?

2. What is the feasibility of these innovations in practical case studies?

C) Governance mechanisms

1. What mechanisms can be identified that influence mainstreaming of innovative

concepts in urban water management?

2. What is the practitioner receptivity to changes in urban water management and

application of innovative concepts?

3. What would be useful strategies and recommendations to achieve mainstreaming

of innovations in urban water management to contribute to cities that are less

vulnerable?

12 Chapter 1. Introduction

1.3 Research context

This thesis is based on results from the research project’ Transitions to more sustainable

concepts of urban water management (Transitions SUW). This project (2005-2009) was executed

by a consortium of 12 organisations as part of the research program Living with Water (Leven

met Water). The consortium consisted of both researchers and practitioners. The project did not

only include scientific objectives, but also practical objectives such as implementation of urban

water management innovation. For more information about this project the reader is referred to

the Appendix. One of the objectives of the research program was to bridge the gap between

science and practice in water management. This was considered important for two reasons. First,

by connecting these two fields, new technologies that are developed will respond better problems

in practice. Second, potential technical solutions that have been developed may more easily find

their way to practice. Van Kerkhoff and Lebel (2006) distinguish six levels of increasing

engagement and power sharing, in cooperation between researchers and practitioners.

This particular research project to a certain extent had elements of all the six types of

research that are summarised in table 1.1. However, in general the project is most similar to type

4, integration. In this project, one of the key requirements was interaction with practice.

Therefore, a three track parallel research approach was applied. This means the approach was

characterised by the parallel development of technical innovations, the study of societal aspects,

and strong theory-practice connection in case studies track (De Graaf and Van de Ven, 2006).

In the case studies, innovations with practical applicability were developed. Early in the

project information about feasibility was gathered. By implementing innovations in case studies,

more information was generated about opportunities and obstacles that enable or constrain,

mainstreaming of these innovations. This information was used to improve the innovations in

urban water management. Detailed information about the project approach and methodology can

be found in the next paragraph and the case study chapters. These chapters also contain a

reflection on the use of research results in practice.

Table 1.1 Levels and types of cooperation between practitioners and scientists (Van Kerkhoff and Lebel, 2006)

Level Type Role of practitioners Role of scientists

1 Trickle Down Consult academic publication Publish in peer-reviewed journals

2 Translation Consult published sources Engage in science communication

3 Participation Consult scientists directly Gather and consider practitioner

input

4 Integration Tie research funding to governance, and

shared accountability

Funders require specified interaction

with practice

5 Negotiation Recruit researchers to support political

agendas

Seek out influential practitioners to

further a contested agenda

6 Learning Recruit researchers to clarify and solve

problems

Engage practitioners in iterative

processes of research and action

1.4 Research methods

To answer the research questions, different activities were executed in this research. To address

research question A1, a literature survey was done to make an overview of theoretical concepts of

vulnerability. Based on this overview, vulnerability was defined as a framework that consists of

four components. This framework was subsequently applied to water management in two

countries, the Netherlands and Japan. Application to water management in the Netherlands

13

showed that current water management strategies mainly focus on large scale infrastructure rather

than local solutions. Examples are given of alternative measures that can be used to develop

more comprehensive strategies to reduce the vulnerability of cities. The purpose of the Japan

chapter was to develop ideas and illustrate the vulnerability framework with examples from this

country (research question A2). The situation in Japan was in particular interesting with regard to

climate adaptation of urban water systems. This country has already an extreme climate that

causes both floods and droughts. Moreover, similar to the Netherlands, it is a highly urbanized,

industrial country with a high percentage of invested capital and population in flood prone areas,

including areas under sea level. Thus, the systems that are in place in Japan can provide us with

ideas how Dutch urban water systems could function in the future.

1.4.1 Action research in case studies

Two case studies in the city of Heerhugowaard were done to evaluate the technical feasibility of

urban water management innovations in practice in order to address research questions B1 and

B2. The case studies were also used to develop insights in mechanisms that determine adoption

and mainstreaming of technical innovations (research question C1). In the case studies, the

author of this thesis actively participated in executing the research in project teams. These teams

included other researchers and practitioners from the consortium partners. More detailed

information about the project team approach can be found in the case study chapters. The role of

the researchers and practitioners in the case studies can be considered the role of reflective

practitioner (Schön, 1983). This means they developed insights and critically reflected on their

observations while being involved in the practical process of technology application as members

of the project team. Critical reflection took place every 6 months in general meetings of the

Transition SUW project. In addition, more frequent case study meetings were organised with the

case study team. The researchers established a cooperative relation with the practitioners in the

case study cities. The insights of this thesis are partly based on active participation of the

researchers and practitioner experiences in the case studies. Since this thesis is concerned with

developing insight on the application of technical innovations in practice (research questions C1

and C2), active collaboration of the researchers with practitioners was a more suitable method

than an external viewpoint as neutral observer.

The method that was applied in the case studies can be considered Participatory Action

Research (PAR). Traditional research aims to advance knowledge by developing theories and

testing hypotheses. The objective of PAR is not only to advance scientific knowledge, but also to

achieve practical objectives such as improving practice (Whyte, 1989). Therefore, to evaluate this

research project, the casestudy chapters and the last chapter include a paragraph which describes

how the research results were actually used and how an impact on practice was made. These

paragraphs were based on the observations of the author of this thesis. The reliability of these

observations was improved by reflection of the consortium partners during the general meetings

of the Transitions SUW projects. Their comments on case study results and implementation

progress were captured in minutes that were approved in the next meeting. Moreover,

professional reports were made that were validated by feedback from the case study city

representatives before publication. During the preparation of this thesis written questions were

sent to case study city representatives in order to ensure the accuracy of the information on

official decision making procedures.

According to Brydon-Miller et al. (2003) it is likely that social research remains incompetent if

it is executed without developing a collaborative relationship with practitioners. The research

14 Chapter 1. Introduction

results may be published, but they will remain isolated. The added value of PAR is that the

knowledge and expertise of practitioners is used to develop better scientific insights in relevant

social problems. In this thesis, collaboration with practitioners contributed to understanding why,

and under which circumstances, urban water management innovations are applied or rejected.

PAR was therefore a useful research method for the case studies in chapter 4 to 6. Critics of

action research claim that the results of action research are subjective and unscientific. The

researcher actively takes part in the case study, thus cannot be objective. However, the study

topic of this thesis is the dynamic and ever changing social context in which urban water

management innovations are applied or rejected. This means that the empirical results that these

social case studies produce, cannot be reproduced and can only be partially verified, no matter

which method is applied. However, certain mechanisms of technology application that are found

in specific situations can have a general relevance. Case studies can therefore contribute in

revealing these mechanisms.

A point of criticism of case study research that is often mentioned is that it is not possible to

draw general conclusions from a limited number of case studies. However Yin (1984) states that

case studies can be used for theory-related analytical generalisation rather than statistical

generalisation. A method to generalise and substantiate results from case studies is triangulation

or multimethod (Webb et al. 1966). Triangulation is the combined use of multiple scientific

methods to study the same phenomenon (Denzin, 1978). More than one method should be

applied in the validation process and new insights and better understanding can be developed by

combining the strengths of quantitative and qualitative methods (Jick, 1979). This means that

normative case study specific findings, in which application of innovations is an important goal,

are compared to findings from scientific literature, other case studies and more general studies in

order to produce generalisable knowledge. In addition, results should be validated through

discussions with scientists and practitioners.

In this thesis, the results of the case studies are further substantiated through comparison

with scientific theories, findings from literature, and comparison with the general results of a

national survey among urban water management professionals. In these chapters the role of the

researcher is external observer and analyst as table 1.2 shows. Professional case study reports in

Dutch were produced and discussed with the practitioners. In addition, practitioners reflected on

case study findings in general meetings of the Transitions SUW project. Their feedback was

collected, captured in minutes, and was used to improve the reports before scientific publications

were written.

15

Table 1.2 Purpose, method and the role of the author for the chapters in this thesis

Chapter

Purpose (Research question) Methods Role of author

1

Introduce topic, outline and method Literature review External observer and

analyst

Research designer

2 Develop useful framework for vulnerability

Apply framework to Netherlands to evaluate

water management strategy

Outline alternative options

(Research question A1)

Literature review External observer and

analyst

3 Illustrate framework, explore and generate ideas

of alternative options using Japan as an example

(Research question A2)

Literature review

Collaboration with

researcher from Japan

Fieldtrip

External observer and

analyst

4 Proof technical feasibility

Collect experiences and observations on

application of innovations

(Research questions B1, B2 & C1)

Technical feasibility

model study

Participatory Action

Research

Reflective practitioner

5 Proof technical feasibility

Collect experiences and observations on

application of innovations

(Research questions B1, B2 & C1)

Technical feasibility

model study

Participatory Action

Research

Reflective practitioner

6 Explore mainstreaming of innovations by

describing the example of floating urbanisation

(Research question B1, C1 )

Literature review

Participatory Action

Research

Reflective practitioner

7 Review of theories on application and

mainstreaming of innovations.

Identify conditions for mainstreaming of

innovations

(Research question C1 )

Literature review External observer and

analyst

8 Present empirical evidence on factors that

determine key condition 1: including innovation

in spatial planning

(Research question C1 )

Literature review

Case study research

Oral interviews

External observer and

analyst

9 Measure key condition 2: receptivity of

professionals to transformative change

Validate results from chapter 8

(Research question C2 )

Web based national

questionnaire

External observer and

analyst

10 Measure key condition 2: receptivity of

professionals to urban water management

innovations

(Research question C2)

Web based national

questionnaire

External observer and

analyst

11 Draw general conclusions from case studies,

literature and national findings

(Research question C3)

Synthesis Analyst and reflective

practitioner

16 Chapter 1. Introduction

1.4.2 Overview of methods

Various methods were used in this research in order to fulfil the research objectives. This thesis

aims to combine the advantage of action research, such as better practical applicability, with the

objectiveness of traditional research. To determine the main problems and objectives in urban

water management, a literature review was done. In order to develop a useful framework for

water related vulnerability of urban areas, another literature survey was done on the natural

hazards literature. The position of the author in these surveys was external observer and analyst.

The Japan chapter in this thesis is an exploration study to generate ideas on urban water

management innovations, and to illustrate the vulnerability framework. Chapters 4 and 5

demonstrate the technical feasibility of two urban water management innovations in the

Netherlands. These chapters also present observations and reflections of the author on

innovation processes that are further tested in part 2 of this thesis. Chapter 6 on floating

urbanisation draws on literature and the personal experience of the author in mainstreaming of

innovations in the floating urbanisation industry. This chapter is an exploration study to generate

ideas on mainstreaming of urban water management innovations.

The mechanisms of mainstreaming of innovations that are found in part 1 of this thesis, are

further tested through a literature survey in chapter 7 and a national survey in chapter 9 and 10.

Chapters 8-10 aim to validate observations from case studies from part 1 and present empirical

evidence on the two key conditions for mainstreaming of urban water management innovations

that were drawn from the literature survey in chapter 7.

1.5 Thesis structure

This thesis consists of two parts. The first part is about urban water management innovations to

reduce vulnerability of urban areas. The second part of this thesis reflects on social aspects that

are relevant to mainstreaming and application of innovations. Drawing on literature a four-

component vulnerability framework is introduced and applied on Dutch water management in

chapter 2. Examples from Japan to reduce vulnerability are presented in chapter 3. Chapter 4

describes the feasibility of creating a self-supporting water supply for a new urban development

in Heerhugowaard, the Netherlands. Chapter 5 examines the technical and economic feasibility

of using the urban water system as energy source. Chapter 6 reflects on current developments of

using the urban surface water for urbanisation. The chapters 4-6 include a reflection on the

process and how research results were used in practice and follow-up projects.

In chapter 7, literature on social theory is used to develop insights in factors that influence

mainstreaming of innovations. Chapter 8 presents the results of an innovative planning process

that led to mainstreaming of innovations in Rotterdam. In chapter 9, results are discussed of a

survey on the receptivity of the Dutch urban water management sector to change the current

system. The next chapter draws on the same survey, and specifically discusses practitioner

receptivity to the technologies that were described in chapter 4-6. Chapter 11 summarises the

results and provides recommendations that could contribute to improve mainstreaming of

innovations in urban water management to contribute to cities that are less vulnerable. Figure 1.2

presents the thesis structure.

17

Figure 1.2 Thesis structure

Chapter 2:

Four components of vulnerability, theory and application

PART 1: Urban water

management innovations to

reduce vulnerability

Chapter 4: Case

study Heerhugo-

waard, use of local

water resources

Chapter 6: Case study

Netherlands: Using

the surface water for

urbanization

Chapter 5: Case

study Heerhugo-

waard,water system

as energy source

Chapter 7:

Mainstreaming of urban water management innovations, theory

Chapter 8:

Casestudy Rotterdam, Linking water management and urban renewal

Chapter 11: Discussion and conclusions for mainstreaming of urban

water management innovations to reduce vulnerability

Chapter 1: Introduction

Chapter 9:

Receptivity to transformative

change in the Dutch urban

water management sector

Chapter 10:

Perspectives on innovation: a

survey of the Dutch urban water

sector

Chapter 3:

Stormwater management and multi source water supply in Japan

PART 2: Mainstreaming

urban water management

innovations

PART 1: URBAN WATER MANAGEMENT INNOVATIONS TO REDUCE

VULNERABILITY OF URBAN AREAS

2 Four components of vulnerability: theory and

application

2

2.1 Introduction

In chapter 1 of this thesis, the concept of vulnerability was introduced as a theory to develop a

more comprehensive understanding of the potential of alternative water management options.

This chapter introduces a new theoretical framework of vulnerability. In the Netherlands, both

water supply networks and flood defence infrastructure to reduce vulnerability of cities, have a

regional or national scale. Therefore the scope of analysis in this chapter is water supply and

flood control in the Netherlands. The chapters following this chapter discuss possibilities at city

and neighbourhood scale to reduce vulnerability of cities to floods and droughts.

Vulnerability is often defined as the sensitivity of a system to exposure to shocks, stresses and

disturbances, or the degree to which a system is susceptible to adverse effects (White, 1974; IPCC,

2001; Turner et al., 2003; Leurs, 2005), or the degree to which a system or unit is likely to

experience harm from perturbations or stress (Schiller et al., 2001). The system under

consideration can be a community or region. The vulnerability concept is widely used in studies

on risks and natural hazards and often also includes social, ecological and political dimensions.

Stress and disturbances on a system can be both exogenous and endogenous, ranging from

changes in the environment to changes in society.

Some vulnerability approaches consider threats from both inside and outside the considered

system, as well as the capacity of the considered system to cope with these threats. Moreover,

they consider coupled human-environment systems or the reflexive relation between human

society and the environment, instead of only human systems and environmental threats (Fraser et.

al, 2003; Turner et al., 2003; Leurs, 2005). In the risk glossary of United Nations University,

Thywissen (2006) concludes: “vulnerability is a dynamic, intrinsic feature of any community (or

household, region, state, infrastructure or any other element at risk) that comprises a multitude of

components. The extent to which it is revealed is determined by the severity of the event.”

The concept of vulnerability pays attention to both disturbances and system response. The

ability of a system to mitigate stresses and cope with impacts through various strategies is one of

the main determinants of system response and system impact (Schiller et al., 2001). According to

Blaikie et al. (1994) vulnerability is: “the characteristics of a person or a group in terms of their

capacity to anticipate, cope with, resist, and recover from the impact of a natural hazard.” It

involves a combination of factors that determine the degree to which someone’s life and

livelihood is put at risk by an identifiable event in nature or society. Also other authors

(Timmerman, 1981; Bogard, 1989; Dow 1992; Suarez, 2002) link vulnerability to the capacity to

act against disturbances and developments. These capacities relate to a complex set of

characteristics that include initial well-being, self-protection, group protection, hazard

2

This chapter is based on the following publications:

- De Graaf, R.E., F.H.M. van de Ven en N.C. van de Giesen, Alternative water management options to reduce

vulnerability for climate change in the Netherlands. Natural Hazards (in press). Available online:

http://www.springerlink.com/content/0921-030X . DOI 10.1007/s11069-007-9184-4

- De Graaf, R.E., F.H.M. van de Ven and N.C. van de Giesen (2007), The Closed City as a strategy to reduce

vulnerability of urban areas for climate change. Water Science and Technology 56 (4), 165-173.

22 Chapter 2. Four components of vulnerability

preparedness and presence of political networks and institutions (Cannon et al., 2002). A focus

limited to perturbations and stresses is insufficient to understand the impact on systems (Turner

et al., 2003). Thus, to understand vulnerability requires including the abilities and capacities of the

system under consideration. In addition, the capacity to deal with uncertainty is an important

factor that determines the vulnerability of a system. A system may be functioning well today, but

possible future developments may increase vulnerability if a system is not able to adjust to these

developments. Cannon et al. (2002) argue that vulnerability has to include a predictive quality and

conceptualise what could occur to a population in case of a future disaster. Therefore, an

important aspect of vulnerability is the capacity of communities and societies to adapt to

uncertain future developments.

Frameworks that are often used to examine vulnerability take environmental disturbances on

exposed human systems into account (Schiller et al., 2001; Turner et al., 2002). In practice

however, the exposed system may amplify, attenuate, and create stresses and disturbances. This is

illustrated by the fact that a drought can be caused by low river flow, bad water management or

both. Low river flow in itself can again be caused by natural variation of weather, or activities

such as deforestation or upstream reservoir construction. Flood damage might be caused by high

water levels only. However, often it will be a combination of lack of risk awareness, failing

warning systems, lacking or non functioning emergency plans, insufficient maintenance of flood

defence, urbanisation in flood prone areas and high water levels that cause flood damage and

determine its severity.

Also in other complex system such as ecosystems there is a connection between vulnerability

of the system and human practices. Environmental management practices can decrease coping

capacity of ecosystems and make them more vulnerable to exogenous forces such as hurricanes

and fires (Scheffer et al., 2001). These examples illustrate that we are dealing with coupled human

and environmental systems and that an artificial distinction between environmental hazards and

human vulnerability is not sufficient to understand complex interactions between human and

environmental systems.

2.2 Four components of vulnerability

The literature review in the introduction section shows that vulnerability is determined by the

ability to build a threshold against disturbances. Moreover, most reviewed definitions include the

ability to cope with disturbances as a determining factor of vulnerability. Some approaches also

take the capacity to recover from disturbances into account and include future elements in the

approach towards vulnerability (Blaikie et al., 1994; Cannon et al., 2002; Turner et al., 2003).

Vulnerability is therefore defined in this thesis as a combination of four aforementioned

components: threshold capacity, coping capacity, recovery capacity and adaptive capacity. This

vulnerability framework will be further elaborated and will be used to evaluate flood control and

water supply strategies. These are two important components of current water management

practice in the Netherlands. Subsequently, the vulnerability framework is used to identify

alternative options in water management. Table 2.1 illustrates the four capacities framework.

2.2.1 Threshold capacity

Threshold capacity is the ability of a society to build up a threshold against variation in order to

prevent damage. In flood risk management, examples are building river dikes and increasing flow

capacity to set a threshold against high river flow. In case of water supply, examples are

constructing storage reservoirs to increase the damage threshold by preventing loss of service in

23

case of droughts. The objective of building threshold capacity is prevention of damage. The time

horizon lies in the past; past disaster experiences of society are the guiding principle to determine

the height of the threshold. In the Netherlands, for ages dikes were constructed that had the

same height as the highest experienced flood. The dimensions of a water resources reservoir are

determined by historic droughts and water use levels. As a result, the uncertainty of the height of

the threshold is relatively low. The ability of a society to build, operate and maintain threshold

capacity is determined by its environmental resources and its social, institutional, technical and

economic abilities. In the Netherlands, this is relatively well organised. The responsibility of

maintenance of flood defence and water delivery infrastructure is clear. Waterboards are

responsible for maintaining flood defence, water utility companies are responsible for safe and

efficient delivery of drinking water.

Table 2.1 Description of type, hazard frequency, time orientation, uncertainty and responsibility of the four

components of the vulnerability framework that is introduced in this thesis.

Component

Type Frequency

of hazard

Time

orientation

Uncertainty of

hazard

magnitude

Responsibility

Threshold

Capacity

Damage

Prevention

High Day- to day

practice, Past as

guideline

Low Clear

Coping

Capacity

Damage

Reduction

Medium During

emergency

Low Not clear

Recovery

Capacity

Damage

Reaction

Medium After emergency

Low Not clear

Adaptive

Capacity

Damage

Anticipation

Low Future,

envisioning,

pro-active

change

High Undefined

2.2.2 Coping capacity

Coping capacity is the capacity of society to reduce damage in case of a disturbance that exceeds

the damage threshold. For flood management coping capacity of society is determined by the

presence of effective emergency and evacuation plans, the availability of damage reducing

measures, a communication plan to create risk awareness among inhabitants, and a clear

organisational structure and responsibility for disaster management. For water supply, the

availability of emergency and backup water facilities that can be used in case of droughts and

disasters, are important determinants of coping capacity. The objective of developing coping

capacity is reduction of damage, either by reducing flood impacts or by reducing loss of service

for water supply. The time orientation is instantaneous, because in case of emergencies, only

‘here and now’ is important. The uncertainty is low because the magnitude of the hazard is clear

at the time society has to deal with it. Also for coping capacity the ability of a society to build,

operate and maintain it is determined by its social, institutional, technical and economic abilities.

24 Chapter 2. Four components of vulnerability

There is a large range of coping capacity options. In the Netherlands threshold exceeding events

for water management do not occur frequently. This may be an explanation why it is not clear

who is responsible for damage reduction in case of emergencies. Multiple actors such as fire

fighters, waterboards, municipalities, and other government agencies are involved. This is

illustrated by a national government report on critical infrastructures that identifies lack of clarity,

lack of knowledge and lack of coordination between stakeholders as the three most important

problems (MBZ, 2005).

2.2.3 Recovery capacity

The recovery capacity is the third component and refers to the capacity of a society to recover to

the same or to an equivalent state as before the emergency. For flood control, it is the capacity of

a flooded area to reconstruct buildings, infrastructure and dikes. For water supply, it is the

capacity to achieve a functioning water supply and sanitation system again. The objective of

developing and increasing recovery capacity is to quickly and effectively respond after a disaster.

The time horizon is instantaneous right after the disaster but will change gradually towards a

focus on the future. Although economical damage estimates may be difficult, the uncertainty of

the hazard magnitude will be relatively low because the effects will still be noticeable. The

economic capacity of the country to finance the reconstruction determines the recovery success

to a large extent. However, institutional ability and technical knowledge are also important. A

society that is able to recover from impacts of hazards will be less vulnerable for these hazards.

Recovery time may range from weeks to decades, depending on the spatial scale and disaster

magnitude. Recovering from the Katrina hurricane in New Orleans will take years (Kates et al..,

2006). Although in the Netherlands it is clear who is responsible for reinstalling the flood control

and water delivery infrastructure, it is not entirely clear who is financially responsible for

compensating the hazard impacts (Kok, 1996). In the past, the Dutch government often

refunded flood damage to house owners. However, also people themselves or insurance

companies could be responsible, in particular in areas that are not protected by dikes.

2.2.4 Adaptive capacity

Adaptive capacity is the capacity of a society to anticipate on uncertain future developments. This

includes catastrophic, not frequently occurring disturbances like extreme floods and severe

droughts. The time orientation of adaptive capacity lies in the future. Although a system may be

functioning well at present, human and environmental developments, both from inside or outside

the considered system, can put a system under strain and threaten its future functioning.

Examples are climate change, population growth, and urbanisation. Central to the importance of

adaptive capacity is the acknowledgement that these processes may be influenced but cannot be

predicted, engineered or controlled. Because the system cannot be optimized for a known

situation in the future, building adaptive capacity by anticipating on uncertainty is important.

Another reason to develop adaptive capacity is the acceptance that dealing with these uncertain

future developments might require more than improving threshold, coping and recovery capacity.

From this perspective, developing adaptive capacity is a form of the precautionary principle.

Without adaptive capacity, society will try to recover from climate change impacts until it is no

longer possible.

Preventing a technical lock in pattern and securing diversity by keeping options open for

future development contributes to adaptive capacity (Folke et al., 2002; Pahl-Wostl, 2007). New

technologies and innovations will be developed in the future. Adaptive infrastructure means that

25

these options can be incorporated in large technical water management systems. Without

adaptive capacity, promising new technologies that are not compatible with the current system

will be excluded and opportunities will be missed. Water management systems should therefore

be flexible and reversible to allow for future changes to be made. As such, adaptive capacity

improves the freedom of future generations to implement alternative options. The role of

engineers is to make as many options available to society as possible and put these options in

relation to the objectives of society (Harremoës, 1997). Technologies reflect values of society;

they are socially constructed (e.g. Bijker, 2006). Adaptive capacity is therefore also a necessity for

ethical reasons. Adaptive capacity offers freedom to future generations because it enables them

to include technologies in water management infrastructure that reflect their values.

For flood control, the problem of adapting to uncertain future developments can be

illustrated by an example of land use. Although future risks from river or sea floods are unknown,

land use decisions that determine future vulnerability are presently being taken. For water supply,

a good example is salt water intrusion. The sea level and river discharge in 2050 are unknown;

hence also the future problem of salt water intrusion into the Dutch river delta is unknown.

However, the consequences of decisions to construct inlets for drinking water production points

in this delta exceed the horizon of reliable climate predictions. The Dutch drinking water

companies have not yet implemented a strategic vision how to deal with climate change (Kiwa,

2006a).

The objective of developing adaptive capacity is to anticipate on future developments and

impacts by constructing a robust living and working environment. The uncertainty about the

nature and magnitude of future hazards and impacts is high and the frequency of occurrence is

low. The capacity to adapt to these uncertain developments also determines the vulnerability of a

system. Although the exact size and nature of changes are unknown, solutions will have to be

developed for long time horizons and financial and spatial reservations to allow for adaptations

will have to be made. The IPCC (2001) presents many options available for society to increase its

adaptive capacity, varying from technical options to insurance policy and communication

strategies. The range and variety of possible adaptive options is large and the number of

involved organisations in the adaptive capacity determinants is also large. Consequently, there is

no clear picture about who is responsible for strengthening adaptive capacity.

2.2.5 Complex interactions between vulnerability components

It is a societal objective to become less vulnerable to all kinds of hazards, long term and short

term. However, to decrease vulnerability is a complex task. Vulnerability components are highly

connected. Consequently, increasing one vulnerability component could decrease one or more of

the other components resulting in higher, rather than reduced vulnerability. The connection

between vulnerability components is illustrated. Figure 2.1 presents a conceptual damage return

period graph. As a result of dike construction or reservoir construction, environmental variations

with low return periods will cause no damage. This is the threshold domain in Figure 2.1.

Even if thresholds have been built, there will be some occasions when the threshold will be

exceeded. Then, coping with hazard impacts and recovering from them is necessary. This is the

coping and recovery domain in which damage reduction is the prime goal. Finally, there are very

unlikely events with very high return periods where the expected damage is that extreme that

recovery is neither feasible nor possible. These types of occasions we want to prevent by adapting.

Therefore, this is the adaptive domain. However, adaptive capacity is more than what is

illustrated in figure 2.1. It also includes the capacity to deal with future changes in figure 2.1 that

26 Chapter 2. Four components of vulnerability

are still uncertain, due to climate change and other developments. For instance, by more frequent

storms, flood damage might occur more frequently. If the adaptive capacity is high society will be

able to anticipate on this situation. Less damage will occur than in case there is only limited

adaptive capacity and costly emergency and recovery measures will have to be taken.

The conceptual damage-return period graph in figure 2.1 illustrates that by increasing only the

threshold domain, for instance by building higher and stronger dikes for flood control or by

building reservoirs for water resources, the coping and recovery domain becomes smaller.

Increasing threshold capacity may decrease the risk awareness of citizens and reduce their

experience to recover from flooding. An approach that only focuses on increasing threshold

capacity results in a system that is increasingly vulnerable to rarely occurring disasters. Disasters

that cause damage will occur less frequently, but the ones that do occur will cause more damage.

Consequently, for a complete vulnerability reducing strategy, attention should be paid to all

components and domains of vulnerability.

Figure 2.1 The four components and three domains of the vulnerability framework illustrated by a damage return

period graph. The three domains are interrelated, changes in one domain affect the other domains, resulting in an

overall change in vulnerability

2.3 The Netherlands: vulnerability of flood defence

Evaluation of flood defence in the Netherlands is founded on safety design standards that are

based on a probability of exceedance of a certain water level. These safety design standards are

the threshold capacity of society against flooding. In the densely populated western part of the

country, the design return period (T) is highest, T=10,000 years. In the other parts of the country,

the design return period is lower, T= 4000 years, T= 2,500 years and T=1,250. From these

design standards, water levels have been derived that have been used to determine the height of

the dikes (Ministerie van Verkeer en Waterstaat, 2005). Next to coastal and river flooding,

guidelines have been made for pluvial flooding (NBW, 2003). For grassland the return period is

T=10 years, for arable land T=25 years, for horticulture T= 50 years and for urban areas T=100

years.

Recovery Threshold RETURN PERIOD

DAMAGE

Damage Threshold

Threshold domain Coping and recovery domain Adaptive domain

27

Flood disasters of the past have led to a process of continuously increasing the height and

strength of dikes. Because of this process, the damage threshold return period has become very

high. The damage threshold is an average statistical return period of the design water level. In

The Flood Risks and Safety in the Netherlands project Floris (Ministerie van Verkeer en

Waterstaat, 2005), the expected damage of dike failures for multiple locations in multiple

scenarios has been calculated. Expected damage figures range from € 1.9 billion in case of a

single dike failure in Scheveningen up to € 37.2 billion in case of three simultaneous sea dike

failures. The number of expected fatalities range from 100 in case of an expected flood, one

single dike failure and organised evacuation, up to 5090 in case of three simultaneous dike failures,

an unexpected flood and no evacuation (Jonkman, 2007). The annual probability of flooding is

much higher than the design standards, ranging from T=2,500 years in Zuid-Holland to T=100

years in the rivers region. This is due to the fact that dike failures often take place by other

mechanisms than dike overtopping in case of high water levels.

Heavily urbanised areas will be increasingly vulnerable for natural hazards (Mitchell, 1999).

The estimated amount of required new houses in the Netherlands in the period until 2030 varies

from 1 million to 1.5 million in various scenarios (VROM et al., 2005). In the Netherlands,

urbanisation, continued land subsidence and sea level rise will result in increased flood risk

vulnerability. This will result in an increasingly densely populated, increasingly low-lying area

under an increasing sea level. Current national strategies are still mainly focused on improving

threshold capacity. A good example is the recent advice of the Delta Commission on flood

protection and climate change in the Netherlands (Committee Veerman, 2008) to increase

threshold capacity tenfold. Although the report also contains adaptive elements such as a long

time horizon and integration with spatial planning, the report strengthens a sense of absolute

security. The Veerman report has been used as input to develop the National Waterplan

(Ministerie van Verkeer en Waterstaat, 2008a). This plan mentions damage prevention as the

main priority. Out of the six water safety measures categories that are presented in the report,

four categories aim to improve threshold capacity, one improves coping capacity and one

improves adaptive capacity. No recovery capacity improvement measures are mentioned.

Increasing damage thresholds by further rising and strengthening of dikes, will not give

absolute certainty that future disastrous flooding events will have no negative impacts. On the

contrary, absolute security is impossible and statistically there will always be occasions where the

threshold will be exceeded and where coping and recovering is necessary. Adaptive measures to

counter uncertain changes to both more variability of the water level and gradual changes in the

mean water level are needed.

2.4 The Netherlands: vulnerability of water supply

In the western part of the Netherlands, urban areas depend on external river water resources for

their water supply. In the eastern part, mainly ground water is used. In this section vulnerability

of water resources in the Netherlands is analyzed by addressing possible future developments.

In the Netherlands, buffer reservoirs have been constructed by the water utilities to secure

threshold capacity against disruption of source water inlet due to droughts and water pollution.

The water utilities that use the dunes for infiltration of river water have strategic dune fresh water

storage. However, this storage can only partially be used during droughts to prevent damage to

nature areas and to prevent salt water intrusion. Table 2.2 presents the threshold capacity for the

drinking water companies in the western part of the Netherlands that use surface water as a

source for drinking water production.

28 Chapter 2. Four components of vulnerability

Table 2.2 Threshold capacity of water utilities in the western part of the Netherlands. Storage capacity is used to

prevent loss of service during disruption of source water availability, due to droughts or insufficient water quality

(Source: KWR, 2008).

Water utility Inlet point Type of storage Threshold capacity

DZH Brakel (afgedamde Maas) Storage reservoir 2-3 weeks

Evides Gat van de Kerksloot

(Amer)

Storage reservoir 2-3 months

Waternet Nieuwegein (Lekkanaal) Dune infiltration 2-3 weeks

PWN Andijk (IJsselmeer) Storage reservoir 4-6 days

Evides Scheelhoek (Haringvliet) Dune infiltration 2-4 weeks

Oasen Multiple locations River bank filtration none

The vulnerability of Dutch drinking water supply increases due to climate change. Recent climate

scenarios of the Royal Netherlands Meteorological Institute are presented in Table 2.3. Detailed

information about the climate change scenarios for the Netherlands can be found in the scientific

report (KNMI, 2006). Two main driving forces were selected to construct the scenarios by

running combined simulations of both General Circulation Models and a Regional Climate

Model. The first driving force is global temperature change. For the low (G) scenarios, global

temperature increase is +1

o

C in 2050 and +2

o

C in 2100. For the high (W) scenarios, global

temperature increase is +2

o

C in 2050 and +4

o

C in 2100. The second driving force is the change

of the mean seasonal regional atmospheric circulation. This driving force determines the Dutch

regional climate to a large extent. Predominantly western atmospheric circulation, very similar to

the current situation, results in a relatively mild and temperate climate whereas a change towards

more eastern circulation conditions would change the regional climate into a more continental

climate with dry and hot summers. In the + scenarios (G+ and W+), a strong decrease of the

western atmospheric circulation takes place in summer. As a result, warm, dry continental air is

transported to the region. In winter, the + scenarios adopt a slight increase in western circulation.

For the other two scenarios (G and W), in summer a small increase of western circulation

flow takes place. In winter, there is no change compared to the current situation. The four

scenarios were designed to span a large part of possible futures in order to deal with the

uncertainty of future changes. Based on current insights that are derived from current climate

models, the probability that the future climate will be within the range of the four scenarios is

estimated at 80% (KNMI, 2006). Therefore, there is not a ‘most likely’ scenario and all four

scenarios should be used to develop water management options.

In the + scenarios summer droughts will occur more frequently, resulting from lower

precipitation and higher evaporation. The resulting water shortages can be partly covered by a

higher precipitation amount in winter. In that case, however, water storage capacity should be

available. In the Netherlands, limited terrain level differences are available for water storage and

the current water management practice is characterised by artificially maintaining water levels at

fixed targets in polder water systems, thus limiting the potential for water storage. In the other

two scenarios (G and W), the expected increase in evaporation is only little higher than the

increase in precipitation. However, even in case of these two scenarios, the frequency of droughts

may increase. A higher temperature will probably lead to rising water use for agricultural, energy

(cooling) and residential purposes (Van Drunen, 2006). A higher sea level will lead to increased

seepage of brackish groundwater into the Dutch polders under sea level which will in its turn

29

increase the demand for fresh water to flush the polder water systems (Oude Essink, 2001; De

Bruin and Schultz, 2003). Unfortunately, the exact size of these effects of climate change on

water management in the Netherlands is not known. More research, well outside the framework

of this study, is needed to quantify these effects more precisely.

Table 2.3 Four scenarios for climate change in the Netherlands in 2050 relative to 1990. Two driving forces were

selected to construct the scenarios, the change in the atmospheric circulation pattern and the global temperature

change. In the + scenarios there is a strong change in the atmospheric circulation pattern. In the other scenarios this

change is weak. The G scenarios have a relatively small global temperature increase, the W scenarios have a higher

global temperature increase (KNMI, 2006).

In addition to internal water resources such as precipitation, also external water resources will be

affected by climate change. At present, large rivers, in particular the Rhine, generate a relative

constant supply of water to the Netherlands during summer. This constant flow consists for a

considerable part of snowmelt from its Alpine catchment. Melting off peaks usually occur in

spring and early summer (Van de Ven, 1996). However, the mean temperature in Europe is

expected to increase which will generate an earlier snowmelt that will increase the possibilities of

water shortages in summer. The expected summer discharge of the Rhine will decrease with 10%

in an average climate scenario and even 60% in a dry scenario (NMP, 2004). As mentioned,

another effect of climate change is sea level rise, this effect, combined with land subsidence and

lower river discharge in summer can result in problems with salinity. Consequently, water intake

2050 G G+ W W+

Global temperature increase in 2050 +1

o

C +1

o

C +2

o

C +2

o

C

Change of atmospheric circulation Weak Strong Weak Strong

Winter Mean temperature +0.9

o

C +1.1

o

C +1.8

o

C +2.3

o

C

Precipitation +4% +7% +7% +14%

Summer Mean temperature +0.9

o

C +1.4

o

C +1.7

o

C +2.8

o

C

Precipitation +3% -10% +6% -19%

Potential Evaporation +3.4% +7.6% +6.8% +15.2%

Daily cumulative

precipitation (T=10

years)

+13% +5% +27% +10%

Sea level Absolute increase 0.15-0.25 m 0.15-0.25 m 0.20-0.35 m 0.20-0.35 m

30 Chapter 2. Four components of vulnerability

from rivers in delta areas will become more difficult and the chance of water shortage will

increase. The exceedance frequency of a year with very high salinity in the delta, increases with

80% in an average climate scenario (RIZA, 2005). As a result, water inlets will have to be closed

more often. The current strategies to address these challenges are focused on optimizing the

current system by improving threshold capacity. In the Nation Vision on the Waterchain (VROM,

2003) local water resources are not mentioned. In the Household Water Policy Statement (Van

Geel, 2003) the national government has adopted a restrictive policy for alternative water sources.

The position papers of the Dutch Association of Dutch Water Companies Vewin are primarily

focused on efficiency improvement. The position paper on climate adaptation is focused on

protecting current sources rather than developing new sources (Vewin, 2009). Only recently, the

water utilities have been appointed as partners in crisis management by the minister of Ministry

of the Interior (Vewin, 2009).

All mentioned developments in this chapter, summer river discharge, precipitation, and sea

level rise are characterised by wide margins of uncertainty. At present, little is known about the

specific effects of climate change on water management in the Netherlands. This is in particular

the case for urban water management. However, the size of changes and precise effects may be

uncertain, the direction of change is not. All mentioned developments and effects in this chapter

contribute to more frequently occurring droughts in the future (RIZA, 2005). Therefore, cities

that continue to depend only on one single external water resource, either river water resources

or external groundwater resources, will be increasingly vulnerable to droughts. In addition heavy

rainstorms are expected more frequently which will result in more pluvial flooding with the

existing urban drainage infrastructure.

2.5 Towards reduced vulnerability

It is important for urban areas in general, to become less vulnerable to flooding and droughts.

For that purpose, all four components of vulnerability should be taken into account. Not only

strengthening and raising dikes, but also investing in risk communication, emergency plans, and

experimenting with other modes of urbanisation. Not only focusing on better and more efficient

water storage and delivery infrastructure but also on demand management, water saving

technology and decentralised, more flexible water supply. This adds diversity to the options

society has available to face uncertain future developments and disturbances. In many fields of

science, strengthening diversity as vulnerability reducing measure has been advocated. Examples

are ecology, corporate management sciences, public management sciences and economics.

2.5.1 Lessons from other fields of science

According to the Panarchy theory, human and natural systems are more capable to cope with and

adjust to shocks and disturbances if they are more diverse (Gunderson and Holling, 2001). The

Panarchy theory was developed by landscape ecologists that applied the theory to a broader

context as well by studying social systems. However, also in other scientific disciplines diversity as

a strategy to reduce risks under conditions is mentioned.

In economics for instance, portfolio management is used to reduce risk to investments for

future uncertain disturbances. By building a portfolio of investments with a low mutual

correlation the investor minimises effects of disturbances on his returns. Fraser et al. (2005) have

shown that applying the concept of financial portfolio management offers insight in reducing the

vulnerability of urban supply chains, in their case food supply of urban areas.

31

In corporate management sciences, the interlinkages between diversity, vulnerability and

supply chains of resources and products are studied as well. In The Resilient Enterprise, Sheffi

(2005) shows that diversity and flexibility in the supply chain of companies, can give them

competitive advantages over their rivals in case of unanticipated disturbances such as fires, strikes

or terrorists attacks. More diversity leads to a company that is less vulnerable to uncertain future

disturbances. The recovery capacity of a company to bounce back after a disturbing event is

enhanced by building in redundancy and flexibility.

In public management sciences, diversity is also an important aspect. An approach to deal

with complex problems under conditions of high uncertainty is transition management (Rotmans,

2003), which focuses on realizing a societal transformation to decrease vulnerability. Transitions

typically take a generation or more to develop. Transition experiments are small scale

experiments aimed at sustainable system innovation. For highly complex problems, by definition

it is impossible to develop the solution beforehand (De Bruijn et al., 2002). After all, the effects

of climate change are uncertain and so are the available future technologies and their

consequences. Therefore, experimenting and learning by doing is necessary. By executing

transition experiments, learning with new modes of supply, takes place rather than optimizing

existing infrastructure. The information and experience gained by these experiments provide

diversity to society and are used to improve other experiments. This improves the adaptive

capacity.

Current vulnerability reducing strategies of water supply companies mainly focus on

threshold increasing measures and little on coping capacity measures. Examples of threshold

capacity measures are constructing improved water storage and delivery infrastructure. This is not

a complete vulnerability strategy. This chapter identifies options to add coping, recovery and

adaptive components to current strategies in order to achieve a complete vulnerability strategy.

To quantify the effectiveness of these options to reduce vulnerability for climate change is not yet

possible because (1) there is no information yet about the specific impacts of climate change on

local urban water systems in the Netherlands and (2) information about the effectiveness of new

local concepts for water supply and flood control is lacking since most research is aimed at

optimizing the current water management infrastructure. Therefore, within the scope of this

chapter, vulnerability reducing options will be discussed by using the vulnerability framework to

describe alternative measures. Some of these measures will be further studied in chapters 3 and 4.

Based on the four component vulnerability framework, Table 2.4 gives examples of vulnerability

decreasing measures for water supply and flood control. For a comprehensive overview of more

than 150 measures to improve the climate robustness of cities, the reader is referred to Van de

Ven et al. (2008).

2.5.2 Reducing vulnerability to flooding

Section 2.3 demonstrated that in flood control, the emphasis is on increasing threshold capacity

to reduce vulnerability. Examples are constructing higher and stronger dikes and increasing the

discharge capacity of rivers. As figure 2.2 illustrates, this could lead to a lock in situation in which

urbanisation leads to higher dikes which leads to more urbanisation, which leads to increased

flood risk, which leads to higher dikes. The result is that disasters occur less frequently, however

if they occur the effects are more disastrous. Geldof (2001) calls this mechanism societal rebound.

Flood control measures decrease flood risk. Society potentially reacts on the decreased flood risk

by starting more activities in this area which partially cancels out the effect of flood control

measures.

32 Chapter 2. Four components of vulnerability

Instead of this lock in strategy, urbanisation strategies could be developed that include all

four capacities to reduce vulnerability. Timely flood warning and improving risk communication

would make residents better prepared to cope with flooding. The current potential for evacuation

in the Netherlands is limited, however, this would be different in the future if there would be

more local shelter and emergency refuge areas. Flood proof buildings in urban areas reduce

damage during floods and can function as shelter.

In addition to securing threshold capacity, improving recovery capacity could be done by

insuring flood risks and disaster funds. Recovery plans and recovery training may contribute to

faster and better recovery. This will reduce the overall vulnerability of an urban area. Adaptive

measures, finally, would for example be experimenting with other modes of urbanisation that do

not or less, increase flood risk. Such modes of urbanisation are wetproofing and dryproofing of

buildings, building on mounds, building on piles or constructing floating cities (Van de Ven et al.,

2008). Adaptive measures would have two mitigating effects: 1) buildings and the urban

infrastructures are more resistant against the impacts of flooding and 2) local refuge areas are

created that provide shelter for residents during floods. Flexible and reversible infrastructures

allow for the incorporation of new technologies that will be developed in the future. For this

purpose, the development of multiple modes of flood proof urbanisation is required. Reservation

of space for water retention improves the future ability to adapt to more frequent flooding and

droughts. This measure requires the integration of water management and spatial planning. A

broad range of actors such as insurance companies, construction companies, municipalities, and

residents should be involved to successfully develop a complete vulnerability strategy. It is

needed to start an explorative learning process by experimenting with more climate robust

concepts of urbanisation, in order to increase the options of society in face of uncertain future

developments.

Figure 2.2 Only increasing threshold capacity could create a lock in that leads to increased vulnerability. Instead, all

four capacities of the vulnerability framework should be addressed.

Coping

Capacity

Adaptive

Capacity

Threshold

Capacity

Recovery

Capacity

Urbanization

Coping

Capacity

Adaptive

Capacity

Threshold

Capacity

Recovery

Capacity

Urbanization

Increased

flood risk

Higher dikes

& pumping

capacity

Urbanization

Vulnerable delta

Land subsidence

Increased vulnerability

Lock in

Increased

flood risk

Higher dikes

& pumping

capacity

Urbanization

Vulnerable delta

Land subsidence

Increased vulnerability

Lock in

33

Table 2.4 Examples of vulnerability decreasing options for water supply and flood control classified according to

the four components of vulnerability

Water supply Flood Control

Threshold capacity -More water storage

-More efficient water delivery

infrastructure

- Demand management, e.g.

permanent water restrictions

- Use of multiple sources as part of

day-to-day water supply

- Higher and stronger dikes

- Increased river capacity

- Real time control

Coping capacity - Emergency plans, drought

forecasting

- Backup water supply facilities

- Water restrictions during droughts

- Use of multiple sources during

droughts

-Emergency plans, flood forecasting and timely

flood warning

-Improved communication of risks to

inhabitants

- Flood proof urbanisation

- Emergency water storage reservoirs

Recovery capacity - Recovery planning and training

- Disaster funds

- Use of multiple sources as

recovery

- Insurance

- Recovery planning and training

- Disaster funds

Adaptive capacity - Flexible and reversible water

supply infrastructure

- Start a social learning process by

developing experience and

knowledge of multiple sources to

build diversity

-Experimenting with other modes of

urbanisation to build diversity

- Flexible and reversible flood control

infrastructure

- Reservation of space by integrating water

management and spatial planning

2.5.3 Reducing vulnerability to droughts

The expected changes indicate more frequently occurring dry spells, a higher sea level and lower

river discharge. The probability increases that conventional drinking water production by

centralised drinking water treatment plants in the Dutch river delta will be hindered. In such a

situation, water use restrictions, low water reservoir levels and decreasing drinking water quality

will occur. Not only residential water use will be affected, but also industry, shipping, electricity

plants and agriculture. This will result in huge economic losses. In 1976, the driest year in recent

history, the total estimated economic damage was multiple billions of Euros and disruption of

drinking water supply occurred (Riza, 2005). The statistical return period of the 1976 drought is

100 years, however in 2050, the return period of a comparable dry year is estimated to be 45 to

60 years (Riza, 2005).

34 Chapter 2. Four components of vulnerability

During a drought such as 1976, the measures indicated in table 2.4 would mitigate damage.

Examples of measures that increase threshold capacity are the construction of large water

reservoirs and more efficient water delivery infrastructures. These measures provide a threshold

for society against environmental variation. Also structural water restrictions can be regarded as

threshold capacity measures because they permanently contribute to preventing the effects of

droughts.

Coping capacity measures are backup water supply and the use of alternative water sources

during droughts. In urban areas, local water resources such as recycling of effluent and

stormwater could compensate for the lack of river water resources. Stormwater, for instance, is a

relatively clean source that is not yet used for drinking water production. This source has the

potential to make urban districts self-supporting with regard to their water supply. Currently,

stormwater is mostly converted to wastewater in combined sewer systems. By using local

resources in addition to centralised supply, urban districts in the country would not depend on

one single external source but instead use a combination of local stormwater, river water,

recycled effluent and regional surface water. Emergency plans and backup emergency facilities,

such as water trucks and backup water supply points in each city would also reduce damage and

secure water supply for the population. Moreover, recovery to a normal water supply condition

would take place more quickly as cities would not be depending on external water resources only.

An example is fit-for-purpose water use. High quality drinking water is then only used for

purposes that require high quality. For other functions, such as toilet flushing other water sources

are used such as recycled effluent. The experience and knowledge to deal with the risks of local

water sources are currently lacking. Some risks of local water resources will be discussed in

chapter 4. The required societal knowledge and experience can be built by small scale projects

with other modes of supply. This enables society to switch to alternative local sources if

conventional external sources are scarce.

The drought example illustrates the importance of building experience with new modes of

water supply. Our current large scale, centralised water supply may be optimal during normal

supply and demand conditions, however, the system is not necessarily the best choice during

droughts and has a low capacity to adapt due to sunk costs, vested interests, fixed assets and user

expectations. Chapter 7 will discuss this topic in more detail. A possible way to improve the

adaptive capacity is to start a social learning process

Innovations in urban water management to reduce the vulnerability of cities: Feasibility, case studies and governance

Abstract