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

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Abstract

Climate change, urbanisation and land subsidence increase the vulnerability of urban areas to flooding and droughts. Despite the availability of reliable and cost effective technologies, the actual implementation remains limited to small scale demonstration projects. Part 1 of this thesis describes how innovations in urban water management can contribute to reduce the vulnerability of cities. Examples are the use of local water resources, the urban surface water as energy source and floating urbanization. Next to showing the technical feasibility, observations are made from the perspective of an action researcher on factors that contribute to the application and mainstreaming of these innovations. Part 2 of this thesis complements the case study specific view ‘from the inside’ with a perspective ‘from the outside’. To unravel the mechanisms of technology application in urban water management this study included a literature survey, in-depth interviews, discussions, seminars, workshops and a national web-based survey on innovation among urban water managers. This thesis brings together the results of these activities. The study identifies two key conditions for application of urban water innovations in practice. The first condition is including urban water management innovations in spatial planning and development. The second condition is stakeholder receptivity to urban water management innovations. This thesis contains multiple recommendations to improve application of innovations in urban water management. It is relevant for scientists, engineers, designers and policy makers in urban water management.
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
© R.E. de Graaf, 2009
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 by developing experience and knowledge of
multiple sources.
2.6 Conclusion
Based on a review of scientific literature, this chapter demonstrated that vulnerability is
determined by threshold capacity, coping capacity, recovery capacity and adaptive capacity.
Evaluation of the main Dutch national water supply and flood control policy documents shows
that current strategies to reduce vulnerability are focused on improving threshold capacity and
hardly include measures to increase coping capacity, recovery capacity and adaptive capacity. An
approach that only focuses on increasing threshold capacity results in a system that is increasingly
vulnerable to rarely occurring disasters. Therefore, the current national water policy cannot be
regarded as a sufficient strategy to reduce vulnerability of cities to floods and drought. It should
be supplemented with measures to improve coping capacity, recovery capacity and adaptive
capacity. Developing comprehensive strategies that address all four components of the
vulnerability framework is essential if we accept that the environment cannot completely be
controlled, we want to keep options open for future development, and that we are facing
35
uncertainties with regard to the impacts of urbanisation, climate change, demographic and
economic developments on water systems.
In this chapter, the vulnerability framework was used to identify alternative water
management options that contribute to all four capacities of the vulnerability instead of threshold
capacity only. Emergency plans, floodproof constructions, and improved risk communication are
possible coping capacity improvement measures. Multi-source water supply contributes to an
increased coping and recovering capacity of water supply systems during droughts. Insuring flood
risks or setting up disaster compensation funds could increase recovery capacity. Demonstration
projects to increase the diversity of available options, flexible and