Waterplan Rotterdam

Gemeente Rotterdam Wate r s c h a p H o l l a n d s e D e lta H o o g h e e m r a a d s c h a p v a n S c h i e l a n d e n d e K r i m p e n e rw a a r d

wat e r p l a n Hoogheemraadschap van Delfland

Rotterdam

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Index 7 ...................................................................... F p o r e w o r d 10 ................................................................................... S u m m a r y 160 ................................ C o l o f o n

1 . W a t e r p l a n 2 R o t t e r d a m ...................................................................15

- How can water make a contribution to the ambitions of the city?................................................... 17 - What has been achieved and where are we now?................................................................... 18

20 ...................................................................... I n t e r v i e w P i e r V e l l i n g a 22......................... B O X I - S O U RCE S OF IN S P IRATION

2 . W h a t a r e w e f a c i n g ................................................................... 25

- Basic urban requirements: a strong economy and an attrac tive residential environment ............ 26

28 ......................................................................

Interview Adriaan Geuze

- Radical strategies................................................................... 30

- Water and climate ................................................................... 32

36 ......................................................................

Interview Pieter Winsemius

34 ........................ E c o n o m i c r e q u i r e m e n t s

40 ........................ S a f e t y r e q u i r e m e n t s

50 ........................ W a t e r r e t e n t i o n r e q u i r e m e n t s

38......................... B O X II RI S k a pp r o a c h 46 ......................................................................

54 ......................... S e w e r a g e r e q u i r e m e n t s

56 ......................................................................

Interview Hugo Gastkemper

Interview Daan Brakman

58 ......................... G r o u n d w a t e r r e q u i r e m e n t s

- Drought and waterstorages ................................................................... 60 - Water quality ................................................................... 61

62 ........................ W a t e r s t o r a g e r e q u i r e m e n t s

3 . d e c i s i o n s o f c r u c i a l i m p o r t a n c e ................................................................... 66 - Protec ting Roterdam now and in the long term ................................................................... 69

70 ......................................................................

Interview Piet Dircke

- The water is clean ................................................................... 72

7 5 . . . . . . . . . . . . . . . . . . . . . . . . . B O X III - w a t e r q u a l i t y m o d e l l i n g

77 ......................................................................

Interview Piet Kalkman

- Water for an attrac tive city .................................................................. 78

- A properly func tioning wastewater collec tion system is essential for the Water City .................................... 79 - Implementing together ................................................................... 81

82 ......................................................................

Interview CornĂŠ Nijburg

4 . 2 0 3 0 R o t t e r d a m v i s i o n ................................................................... 85

- Three principal areas., Three strategies ................................................................... 87 - Rivierstad - The rivercity ................................................................... 90 - Nor th ................................................................... 92

- South ....................................................................... 94

96 ......................................................................

Interview Karin Schrederhof

98......................... B O X IV - W a t e r p l a z a s 106........................ B O X V - G r e e n r o o f s

108........................ B O X VI - P u t t i n g t h e r i v e r R o t t e b a c k o n t h e R o t t e r d a m m a p

- Conceptual solutions by city distric t type ................................................................... 110

5 . i m p l e m e n t a t i o n s t r a t e g y ................................................................... 117 - Proposition and phasing ................................................................... 119

- Collaboration and organisation .................................................................. 125 - Costs and cost allocation.................................................................. 127

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Inter view Marion Vredeling en Jan Buijs

- Communication concerning teh Rotterdam Waterplan 2 ................................................................... 132

6 . i m p l e m e n t a t i o n p r o g r a m m e 2 0 0 7 - 2 0 1 2 ................................................................... 135 - Implemented projec ts ................................................................... 137

- Coalitions and Innovations ................................................................... 146

151 ......................................................................

Interview Ed Aldus

- Research projec ts ................................. 152

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Foreword

We proudly present Waterplan 2 Rotterdam, which has been compiled jointly by the

Municipality of Rotterdam (the Public Works Department, the Town Planning and Housing Department (dS+V) and the Rotterdam Development Corporation), the Schieland and Krimpenerwaard Water Control Board, the Hollandse Delta Water Authority and the Delfland Water Control Board.

Why has a new water plan been drawn up? In recent years we have been swamped by a tidal wave of new policies on water management and spatial planning at regional, national and European level. The media have also been focusing intensively on climate change, rising sea levels, subsidence, (undesirable) building in deep polders, the importance of good water quality, water safety and flooding.

In the discussion we held in the context of Waterplan Rotterdam, we came to the conclusion that water and spatial development are inextricably linked. The only way to tackle our basic water requirements is by incorporating them in our approach to urban planning. And, conversely, the issue of water can also give enormous impetus to urban planning design aspects of a city - particularly a city like Rotterdam, which, after all, describes itself as a ‘water city’. An excellent and now well-known example of this synergy is our entry for the second International Architecture Biennale: Rotterdam Water City 2035.

The municipality and the three water boards put in an enormous amount of effort and work into the previous plan, Waterplan Rotterdam 2000-2005. Examples include Zuiderpark, the Singelplan (canal plan), the Bergse Plassen and the Zestienhoven polder, but also general programmes and measures such as large-scale dredging of the waterways, improving water quality, and replacing and improving the wastewater collection system. The municipal district water plans, which include an analysis of the water flow levels to establish what measures will be needed to design the system in the most effective way, were also launched. And these measures have in fact been, or will be, implemented.

The basic water requirements, which have been combined with the basic urban planning requirements as presented in the Rotterdam City Vision and the related Spatial Planning Strategy 2030 more and more often in recent years, require a new approach. The Water Action Programme in Waterplan Rotterdam 2000-2005 will continue to apply unchanged. The new issue is also outlined in this water plan. What are the challenges for the next few years, but also for the longer term? How can these be translated into a new perspective? What essential choices are they based on? And what form would a realistic implementation programme take, allowing for phasing but at the same time providing direction? The keywords here are cooperation and cohesion - words that also applied to the process of creating this water plan. All this has resulted in this broadly based plan.

The storyline is interspersed with interviews with empirical experts, stakeholders and administrators, aimed at obtaining as diverse a picture as possible of the requirements we are facing, but also aimed at making it clear that water is a subject that is an integral part of society and our outdoor space, and can be both a problem and an enhancement.

It also includes separate frameworks presenting some examples of attractive projects: integral water projects with clearly defined objectives, but also flagship projects that are particularly innovative or appealing on account of their unconventional approach.

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This document is not the definitive product, however. The Waterplan Rotterdam should be regarded as a dynamic process in which the discussion with the water plan partners continues on an ongoing basis. In addition, project teams are working on continuously improving the entire water system and its interaction with the city’s urban design concept.

What you have before you is a document that sets out an implementation programme that is not only ambitious but also realistic. One which outlines the need to tackle the issues now so that we can face up to our future basic water requirements. But one in which we also set out how we are going to use our approach to these requirements to make Rotterdam an attractive city to live in, in which we can continue to develop our strong economy.

The result is Rotterdam Water City, protected against water and living with water, in which we can enjoy living, working and relaxing.

Municipality of Rotterdam: Alderman L.M.M. Bolsius Alderman H. Karakus

Schieland and Krimpenerwaard Water Control Board: Dike Warden J.H. Oosters

Delfland Water Control Board: Dike Warden M.A.P. van Haersma Buma

Hollandse Delta Water Board: Dike Warden J.M. Geluk

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S u m m ar y This ‘Waterplan 2 Rotterdam’ outlines how the municipality of Rotterdam and the water boards want to deal with the city’s water in the period ahead. This needs to be set down on paper, particularly now that the signs of climate change are becoming increasingly clear. This change could have major consequences for Rotterdam. In order to make the city ‘waterproof’, a new approach to water storage, water quality and protection from water is needed.

dykes will form massive barriers between areas. Water managers and urban developers will work together, using them , where possible, as a connecting element, as park landscape, balcony on the Maas or footpath and cycle route.

If Rotterdam starts to build outside the dykes, the design will also have to take account of possible higher water levels in the future, the so called adaptive approach. In short: measures have to be taken now, even if they will only have an effect in the longer term.

The water action program of the last water plan is still in progress, but a new water plan was necessary

C l e a n w at e r ‘Clear and plant-rich water’ is the general objective for water in Rotterdam. With the right

because of new developments and insights. The vision in the current plans goes up to 2030. That year

mix of measures, that goal is feasible for almost all stretches of water in the city.

was chosen because the City Vision also looks ahead to 2030. In the City Vision, the municipal council states what it has in mind for Rotterdam: a city with a strong economy and an attractive place to live. This

At t r a c t i v e c i t y This is perhaps the most important decision: how can the city be made even more attractive

development and all the measures in this water plan are closely connected.

as a place to live, work, study and spend leisure time, and can the water problems be solved at the same time?

Traditional solutions are inadequate here. In the city centre and the old neighbourhoods, for example, it isn’t

Plenty has been done in recent years. More open water has been created in the revamped Zuiderpark,

possible to tackle the problems of water storage by digging extra facilities. The costs are exorbitant and existing

thereby increasing the storage capacity. The banks have been redesigned, the ecology has been improved

buildings can’t simply be demolished. Innovations such as green roofs, ‘water squares’, alternative forms of

and there is now more space for recreation. Canals and brooks in Noord and Zuid have been cleaned up and

water storage and the like are therefore essential for the further development of the city.

the quality of the water here has improved tremendously. The Bergse Plassen have been spruced up, so that the water is now clean and clear again. Other big projects are still under way. Furthermore, the municipal

S e w e r s In practice, rainwater usually drains away via the sewers. The increasing rainfall is leading to

authority is busy implementing the measures as mentioned in the Municipal Sewerage Plan.

problems with the existing sewerage system. One possible way of avoiding these problems is to collect the rainwater and allow it to drain away in a system other than the sewers, therefore separating the dirty waste water from the relatively clean rainwater. However, this system must not be allowed to adversely

What we are facing

affect public health, the quality of the groundwater or the groundwater levels. It’s no picnic to reconstruct Rotterdam’s sewerage system. Sewage pipes last around fifty years; the reconstruction would take up

Rotterdam is working on a strong economy and an attractive residential environment. Water is an

several decades. According to a recent social cost-benefit analysis, complete division throughout Rotterdam

important aspect of an attractive city, certainly one that profiles itself as ‘water city’. The vision of

would not be the best solution. For this reason, an approach for each type of area is being sought.

Rotterdam for the future plays an important role in all the plans.

In addition, there are three crucial developments with which we will, or might be, faced in the period ahead.

• Higher water level due to the rise in sea level. There is a risk of flooding in areas outside the dykes.

Flood defences will simply have to be reinforced.

• Flooding caused by increasing rainfall. Due to the changing climate, a lot of rain can fall in a short space of time. In order to process that water, provisions are needed for collection and storage. At the

Perspective on Rotterdam Water City 2030 The plans for Rotterdam Water City 2030 consist of enhancing existing qualities and responding cleverly to new developments. Chapter 3 was about the choices which have to be made; this chapter looks at the consequences of these choices, divided into three main areas.

moment, there is already a shortage of around 600,000 m3 of storage. At least 80 hectares of extra lakes and canals would be needed to cope with this shortage by means of open water.

• Stringent demands on the quality of water. Rotterdam wants to be an attractive water city, with clean, clear and plant-rich water. The city must also meet European requirements (the European Framework

R i v e r C i t y River City consists roughly of the area outside the dykes. The key feature of River City is the

Maas, the trademark of Rotterdam, the city’s lifeline. The river connects the port – the economic motor – with the hinterland.

Directive on Water). So-called quality profiles, based on these requirements, are in the process of being drawn up for all stretches of water in the city.

Rotterdam has a characteristic waterfront, with the Kop van Zuid, the Lloydkwartier and new construction sites.

There is space here for a wide range of dynamic areas in which to live and work. At the same time, the river

Decisions of crucial impor tance

provides opportunities for more transport by water: that reduces travelling time and improves the accessibility of these areas. Furthermore, Rotterdam could distinguish itself from other cities with this form of transport.

In order to solve the problems referred to above, choices have to be made. These are the so-called ‘decisions

A recreational route can be created along the whole length of the river; a succession of unique spots, which

of crucial importance’.

together form the city’s largest recreational area.

P r o t e c t i o n Rotterdam needs to be protected against flooding, both inside and outside the dykes. All

R o t t e r d a m - N o o r d On the northern banks, there are many popular residential and commercial areas:

quays and dykes which are not yet high enough, according to the current standards, will be reinforced in

most of the centre, Kralingen, Blijdorp, Hillegersberg, the Brainparks and Alexander. Water makes a

the coming years. But in the more long term too, the city will have to be protected. For this reason, space

massive contribution; living alongside water is very popular. The aim for this part of the city is to build

needs to be reserved now for enforcing the flood defences in due course. This does not mean that these

further on these existing qualities.

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Rotterdam-Noord has ‘boezems’ (drainage pools) and canals which serve as water storage, but a large part

Qu a n t i t y o f w at e r In the coming years, Rotterdam will have to store more rainwater than is currently

of the storage is via the sewerage system. The strategy is to reinforce the canals and boezems and extend

the case. The Municipal Sewerage Plan already contains many relevant measures. Another approach is

them where possible, and to use innovative solutions when space is in short supply, such as in the city

to create more space for open water. This is possible particularly in the neighbourhoods earmarked for

centre and the old districts.

restructuring. Examples include Groenehagen/Tuinhoven, Hordijkerveld, the northern side of Lombardijen and Oedevlietsepark. Where there is no or little space, we will have to focus on innovation and alternative

R o t t e r d a m - Zu i d Zuid requires an unconventional approach. That’s because the problems are not

ways of retaining water. Examples are wadis, water gardens, water squares and green roofs. There are

run of the mill either. There are exceptional opportunities here, however. Zuid is an area rich in water,

pilots in the pipeline for the last two examples. There will also be a study into solutions for the problems

with its (inner) ports and possible water connections. The water could be put to even better use, but that

anticipated in the city centre, Oude Noorden, Crooswijk, Overschie and Oud-Zuid and the industrial estates

would mean encroaching fundamentally on the urban area. Possibilities are: to reinforce and extend

Spaansepolder and Noordwest.

the water structure from within the Zuiderpark; to create new water networks from existing and new canals, watercourses, Zuiderpark and the districts earmarked for restructuring and to link Zuid with the

Qu a l i t y o f w at e r Rotterdam and the water boards are striving to improve the quality of the water by

surrounding area via a new north-south connection.

2015. They are doing this, on the one hand, because Europe has drawn up relevant guidelines, but also because such water has more potential uses, is perceived to be better and has greater economic value.

Realization strateg y

A completely clean water system within ten years is not feasible, however. It costs a lot of money and the effects of measures are often only visible in the more long term. We have therefore chosen to prioritise.

A strategy is needed if the water plans are to be achieved. This consists of prioritising (what definitely has

Thanks to a special system of water quality profiles, we can choose measures which are practicable,

to be done in the coming years?) and phasing (which measures do we take when?).

technically feasible and affordable. We apply this approach particularly in the municipal district water plans. Apart from this, the watercourses which are not yet being tackled in this way must meet certain

Basically, there are three types of measures.

minimum criteria: as little floating waste, complaints about the stench and dead fish as possible. There will

• Improving the water system: what do we do, for safety’s sake, to combat flooding and to improve the quality of the environment?

also be a study into possibilities for fish migration and a comprehensive plan for the fish stock, with a focus on the ecological value of the waterways.

• Enhancing the urban quality: how do we link Rotterdam’s development plans with what needs to be done in terms of water?

In order to ensure that the starting points of the water plan are actually put into practice, also

• Introducing innovative and alternative solutions: what do we do if the traditional approach is inadequate?

organizationally, it is essential that collaboration between municipality and water boards and between water specialists and urban designers will continue.

To prioritise, a list of criteria was drawn up. What is important, for example, is the question, if a project

The foregoing results in the ambitious implementation programme for the years 2007 – 2012 in which the

is already under way, of how this helps solve the water problems, how it contributes towards an attractive

projects are described in detail.

city, if there is a ‘now-or-never’ situation and if there is evidence of an exemplary effect.

Imp l e m e n tat i o n p r o g r a mm e The Implementation Programme 2007 – 2012 sets out what needs

to be done in the next five years. This involves ongoing projects from the first water plan, new projects and studies, which are already being conducted so that we can carry on quickly after 2012. They can be subdivided into projects to improve safety, projects to cope with the quantity (thus storage) of water and to improve the quality of the water.

S a f e t y The safety aspect involves two main themes: the dykes and building outside the dykes. The starting

point is that the city is and remains protected from the water. In the more long term, choices will have to be made about the storm surge barrier and the required height of the dykes.

During the implementation period of the water plan, those sections of the dyke which do not yet meet current standards will be reinforced. The flood defences at the Vierhaven and Merwehaven also require attention. As soon as the examination method is made known, detailed examination can be carried out here and a study can be launched into adaptive building in this port, as well as in the Rijnhaven and Maashaven.

For the areas outside the dykes, proper account must be taken of the risks of flooding. Newbuild and the design of the area must be geared towards this, evacuation must be possible and communication with the residents is a precondition. For the coming five years, studies on these aspects are on the agenda.

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Wat e r p l a n 2 R ot t e r da m This is the main report of the Water Plan 2 Rotterdam. It describes the approach that the City of Rotterdam and the local water boards are proposing to take towards the water in the city.

The plan is the successor to Water Plan Rotterdam 2000-2005.

There are three reasons for bringing the 2000-2005 plan up to date: the period covered by the original plan has now elapsed; we now have to deal with new ideas and more recent legislation in the field of spatial planning and water management; and finally it is now becoming ever clearer that the climate is changing, which for Rotterdam is of great significance. In order to be able to face up to these challenges a new way of dealing with water is required, as conventional solutions are inadequate.

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1.1 How can water make a contribution

to the ambitions of the city?

Water and Rotterdam are inseparable. Water forms a fundamental part of the city and has

played a crucial role in its development: the Maas, the Schie, the Rotte, the many canals and lakes and the ports – all are characteristic features of the city of Rotterdam. However, the various water systems are under pressure and limits have by now been reached. Legal and physical developments have led to the conclusion that a fresh approach and new investments are required in order to make Rotterdam ‘waterproof’ in the future. The three main themes in this context are water storage, water quality and water safety.

During the next few years Rotterdam is seeking to further develop into a city that is pleasant and safe to live in, with good employment opportunities and a healthy environment. A great deal of building work will be needed during that time and parts of the city are on the threshold of some far-reaching restructuring programmes. Rotterdam recently presented its City Vision. The city’s mission is to continue to work on creating an attractive city with a strong economy. The central question that this water plan attempts to answer is how the water – in all its facets – can contribute to these objectives being achieved.

Rotterdam is faced with a huge challenge. Slowly but surely the city is casting off its image as an ugly port and industrial centre and is actively turning itself into an appealing residential city.

To the extent possible, Rotterdam wants to use the potential offered by its existing urban area, aiming at developing attractive residential environments. However, this requires more than just good-quality homes.

It also involves the creation of links to existing identities, the provision of appropriate educational and other amenities, the quality of public spaces, air quality and, last but not least, water-related requirements.

Tackling water-related requirements is an important precondition for achieving an attractive living environment. Conversely, it is true that if we want to deal with water-related challenges effectively, it will only be possible if we include them as part of the city’s development.

This water plan offers a view on Rotterdam in 2030. It focuses on the city’s longterm development with regard to water and dams, without losing sight of the city’s ambitions. In order to realise this view we have to act now and make some fundamental choices. What these choices are is described in Chapter 3, ‘Decisions of crucial importance’.

The period of the long-term vision – up to 2030 – has not been selected at random. It is in line with the City Vision in order to re-emphasise that spatial and water-related challenges are interrelated.

The water plan has been co-produced by the City of Rotterdam, the Schieland and Krimpenerwaard District Water Board, the Hollandse Delta Water Board and the Delfland Water Board. In 2006, the ideas to be contained in the plan were developed in a number of working parties and six design studios, with urban planners, landscape architects, drainage experts, specialists in water management, ecology and water quality, security, design and management, and many others working intensively together. The aim was to

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arrive at a truly integrated water plan. In addition, the structure of the water plan was presented to other

In the last few years, existing canals and streams in Noord and Zuid have been smartened up, including

water partners like the Dutch Directorate for Public Works and Water Management, the Port of Rotterdam,

a number of canals from the Rose Plan. Areas of greenery around the canals have been improved, as has

the Zuid-Holland provincial government, and the DCMR Environmental Protection Agency.

the layout of the streets. Each facade was restored, and the quality of the water in the canals has improved tremendously. The Bergsingel, Noordsingel, Crooswijkse singel and the Boezemsingel canals are now back to

2.1 What has been achieved and where are we now?

how they should be. The canals and streams in Zuid are also being tackled.

The integrated recovery plan for the Bergse Plassen lakes has now been completed. Thanks to a package of measures including dredging, the construction of a sewerage system, improvements to the layout, the

Although there have been many new developments, and arguably a change of course with regard to

removal of phosphates from the water of the canal inlet from the direction of Hillegersberg, the management

water management, a great deal of work has already been carried out in recent years. The Water Plan

of fish stocks and the creation of places for pike to spawn, the design and quality of the water has improved

Rotterdam 2000-2005 embraced a wide range of issues and considerable achievements were made by the

enormously, and the water is now clean and clear. The final measures will be implemented during the period

time it had run its course. Large projects were, and are, carried out. We have restored canals and we have

covered by the next plan, including insulating the lake by constructing a drainage route for water from the

already started the much-needed task of storing water, while the improvements to the quality of water are

residential areas.

becoming visible. The necessary work for the sewerage system has been done, and the backlog in dredging work has now been cleared.

An important interaction exists between drainage systems and surface water in the Rotterdam urban area, and as a result there is also a close relationship between the Municipal Sewerage Plan (known as the GRP)

What can we learn from the first water plan? One thing that emerged from the Water Plan Rotterdam

and the Water Plan 2 Rotterdam. The GRP was given the go-ahead by the city council in 2006. It contains a

2000-2005 is that describing a strategic integrated vision may result in an imbalance between vision and

vision on the sewerage system and describes measures to be taken between 2006 and 2010. These include the

the programme of implementation, with the emphasis on the former. For that reason, a greater focus has

replacement of sewerage systems, central management performance targets, almost if not everybody to be

been laid in this water plan on the feasibility of its implementation.

connected to the sewerage system, dealing with precipitation in an innovative way, and obligations with regard to treating groundwater. The measures are in keeping with the ideas behind this water plan and will be further

A second lesson to be learned is that the most successful projects were those that combined ambitions

implemented in the coming period.

that related to spatial planning, such as the Singel Plan and the Zuiderpark. Resources and ambitions were combined and executed jointly with the water partners. This lesson was also carried over to the final

After the Water Plan Rotterdam 2000-2005 was drawn up, it was followed by various municipal district water

implementation programme.

plans (known as DGWPs), which will be completed in the next planning period on a district by district basis.

It can be assumed that the measures that have already been carried out in the DGWPs or which have been

For the Zuiderpark a master plan was drawn up aimed at transforming it into a park fit for the 21 century.

proposed will make a contribution to tackling the city’s water-related challenges. Measures are also needed

This means that the park should be as pleasant and as accessible as possible for a large proportion of the

in the current plan period that need to be worked out in more detail for the municipal district water plans,

population of Rotterdam. New areas of open water have been created, so that the local storage capacity has

particularly those measures regarding sector-based water projects intended to relieve bottlenecks, putting the

increased from 21 to 35 hectares of open water. By redesigning the banks, the ecology has improved, while

water system in order, and focusing greater attention on water quality and ecology (with sufficient emphasis

at the same time there is more room for leisure activities. The overall result is a real water gem.

on monitoring, management, and maintenance).

st

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‘Include climate change when making decisions’ Professor Pier Vellinga is one of the first scientists in the Netherlands who has started to look seriously at the consequences of climate change. Apart from obvious measures like elevating dykes and extra water storage facilities, he sees the solution primarily in government and businesses being prepared to take broad-based action.

“From now on, the climate should be a factor in every infrastructural measure or intervention.”

Roughly speaking, there are two possible types of measures to

respond to climate change. You do something about the ‘hardware’ and decide to improve or strengthen dykes, storm barriers and other protective constructions, or you do something about

the ‘software’, and make sure that houses, roads, pavements,

industrial buildings, bridges, parks, playgrounds, viaducts, etc. are designed, built or modified in such a way that makes them more or completely ‘waterproof’. As far as the hardware is concerned,

the Netherlands has an internationally renowned reputation, but as regards software there is still much room for improvement,

Vellinga believes. He talks of objects that from now on have to

be as ‘climate robust’ as possible – in other words, that they not

only remain standing in extreme conditions, but that they actually help to limit flooding. “Obviously I do not want to open a new

counter where new projects can queue up and be given a stamp of

approval,” says Vellinga, “but it is imperative that the Netherlands, and especially Rotterdam and its hinterland, is properly prepared for the changing climate, so that we can respond flexibly to any

extreme conditions that may occur, and that a range of options are in place which can be deployed as the situation requires.”

Vellinga lays much emphasis on the topic of ‘adaptation’. This refers to estimating in advance what the possible risks and developments are and responding to them accordingly – not suddenly, but gradually and sensibly.

In that context, he believes that Water Plan 2 Rotterdam and in particular the adaptive approach, are ‘an important next

step’, not just towards further protection of the region, but also

towards a more fundamental collaboration between government, industry and science, and between individual government bodies themselves. “Local authorities play an important role in spatial

planning in the Netherlands. If the City of Rotterdam is already looking ahead to 2030 and is coming up with the Water Plan

2 Rotterdam as part of that future vision, then that is a good

signal from which others will hopefully take their cue. Not all government bodies are looking that far ahead yet.”

P i e r V e l l i n g a : ‘ W a t e r p l a n 2 I S AN I M P O RTANT S TE P ’ 20

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B o x 1 - S o u r c e s o f i n s p i r at i o n : T h e R o s e S i n g e l P l a n In using the water challenges for the benefit of the development of the city, we are not unique. In fact, Rotterdam

a n d ROTTERDAM WATER S TAD 2 0 3 5 R o t t e r d a m W at e r s ta d 2 0 3 5 Rotterdam Waterstad 2035 is a real water city, with unprecedented possibilities for

has a tradition in this area of which it can be proud.

new water-based residential environments, transport over water, and a healthy water system. Rotterdam Waterstad

When we drew up this water plan we took inspiration from appealing plans from the past. First of all, there was

the joint entry from the City of Rotterdam, the Hollandse Delta Water Board, and the Schieland and Krimpenerwaard

of course the Singel Plan by the city architect W.N. Rose (1801-1877). The inspiration in this plan can be found in its simplicity and effectiveness, and also because Rose succeeded – even at that time – in making the link between water and spatial planning.

Another example of the synergy between water and urban development is the entry for the 2nd International Architecture Biennale: Rotterdam Waterstad 2035. Rotterdam Waterstad (water city) takes a refreshing and

2035 consists of Rivierstad (centre), Vaartenstad (Rotterdam Zuid) and Singelstad (Noord). Rotterdam Waterstad 2035, District Water Board for the 2nd International Architecture Biennale Rotterdam, gives a perspective on the action that

Rotterdam should take. The plan is inspiring, optimistic, high-profile, evocative and points the way to an attractive city in attractive surroundings. Thanks to its progressive and innovative ideas, the plan received the Architecture Biennale Real Estate Award.

1 . S i n g e l s ta d 2 0 3 5 The strategy in Rotterdam Noord is to strengthen what is good and to intervene wherever

inspiring look at water in the city. Both sources of inspiration are outlined below.

necessary. Typical of the Singelstad townscape are the new canals, which connect the existing canals and serve to

Th e R o s e S i n g e l P l a n Standards of public hygiene in Rotterdam used to be very poor, partly because open

environments will be created here. There will be some delightful squares in Singelstad where excess water from heavy

waters were not only used as open sewers, but also for producing drinking water. As a result cholera epidemics

extend them. The Rivers Rotte and Schie, which had disappeared from view, are set to reappear. New residential

rainfall will be stored. Green roofs will also become common here. 2 . R i v i e r s ta d 2 0 3 5 In 2035 the river will be the

were common, and many thousands of people died!

jewel in Rotterdam’s crown. Rotterdam really is a river city. Possible rises in sea levels are a serious consideration for

In 1854, Willem Nicolaas Rose came up with an affordable plan that benefited both hygiene levels and the spatial

outside the dykes, such as Waalhaven and Merwedehaven, that need to be redeveloped and where all kinds of new

layout of the city. A system of pumping stations, locks, culverts, and a thirty-kilometre long stretch of canal around the old city ensured that the surface water was regularly refreshed. It was possible to live by the water, and

attractive greenery was created. This was in fact a first water plan in which water, spatial planning and improving living conditions in the city went hand in hand.

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Rivierstad. Wherever necessary, dykes will have to be raised in order to protect the city, although there are also areas living environments can be created, including on the water. In addition, water-based transport will serve to ‘re-attach’ these harbour areas to the city. 3 . V a a r t e n s ta d 2 0 3 5 The water in Rotterdam Zuid is virtually all at the same

level, which makes it possible to connect all the bodies of water together, forming one cohesive network. A new and attractive waterway network is developed in Vaartenstad, as are many options for living by the water.

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WHAT WE ARE FACING Rotterdam has several important tasks laid out for it over the next few years, both in the areas of urban development and of water management (security, quality and water storage). These new basic requirements are primarily defined on the basis of new insights into the route the city should take in the long term (as described in the Stadsvisie), the effects of climate change on the city’s water resources, existing and new legislation and regulations (such as the European Water Framework Directive and the Dutch National Policy on Water Management for the 21st Century(NBW)), new insights in the security norm for dykes and the changing role of municipal government (the Parliamentary Act on the Anchoring and Budgeting of Municipal Water Tasks (Wgw).

This chapter goes into these basic requirements. What is the current situation, what are we facing and what requirements will this create? We will first describe the task laid out for the city in the area of urban development, after which we will go into the various requirements in the field of water manageme

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2.1 Basic urban requirements: a strong economy

and an attrac tive residential environment

This section will deal with the urban context. To this end, we will focus in particular on those

elements from the Stadsvisie Rotterdam (Rotterdam Urban Vision) that are important for this water plan.

S ta g n at i n g p o pu l at i o n There is already a fall in the population in many European countries, but in the

Netherlands, for the time being, structural population decline only occurs in various parts of the country outside the Randstad agglomeration. In the medium term (around 2035) the Dutch population as a whole will also drop. The fact that the registered population of Rotterdam fell over the past two years is not a consequence of structural population decline but of locally determined factors such as a drop in influx and undiminished outflux and administrative corrections in the Municipal Basic Administration. A share of the people moving out of Rotterdam is retained for the region, which is still increasing in terms of population. The below diagram shows

Rotterdam’s image is to a large extent based on the city’s water. Rotterdam was born on the waterfront: it is the

the population development from 1992 to 2005 and the trend forecast until 2020 on the basis of the Ruimtelijk

town on the dam in the River Rotte. Rotterdam owes its port to the nearby water. Every Dutchman is familiar

Plan Regio Rotterdam 2020 (RR2020) spatial plan.

with the image of the Rotterdam river banks: the Erasmus Bridge stretching across the Maas River, which shimmers in the evening sun. Rotterdam’s most coveted residential locations are all situated on the waterfront: locations along the city’s canals, riverfront and its lakes and ponds. And water is an important structural Figuur 7. Population development

element: water forms the backbone of the city’s main structure. It’s not just the Maas River with its quays and dams, but also the rivers Rotte and Schie, the canals and lakes, the waterways and the polders. However, if Rotterdam aims to position itself even more clearly as a water city, it will need to place even more emphasis on these qualities and capitalise on them even further.

Besides the city’s aforementioned qualities, which are clearly apparent, various developments are taking place in Rotterdam that are of crucial importance for the city’s future. Rotterdam Urban Vision describes these

When the composition of the local population is unbalanced, a declining or stagnating population will possibly

trends and developments. If Rotterdam intends to stay attractive for businesses, residents and visitors, the city

lead to a decline in prosperity and consequently a weaker base for facilities in the city. In combination with the

will need to take these trends into account. Rotterdam Urban Vision makes a rough distinction between the

present negative selective outflux, this can lead the city to deteriorate, both in social and financial terms. This is at

following trends and categories:

odds with Rotterdam’s need to position itself as a healthy city within the strong, internationally competitive urban

- Internationalisation and modernisation of the economy;

agglomeration of the Randstad.

- Selective migration; Over the next twenty years, due to progressive household dilution (i.e. a drop in the average number of residents

- Stagnating population.

In light of the importance of these developments for Rotterdam’s future and the fact that they will also have an

per dwelling) in the Netherlands and Rotterdam, there will still be a substantial quantitative housing demand.

impact on how Rotterdam plans to deal with its water, they will be briefly discussed in the following sections.

Rotterdam will have to take optimum advantage of this demand in order to house as many highly educated residents – in other words a highly qualified working population – as possible within its city limits.

I n t e r n at i o n a l i s at i o n a n d m o d e r n i s at i o n o f t h e e c o n o m y Thanks to its port, Rotterdam is a

city of international importance and interests. The strategic location of the Rotterdam harbour ensures that it remains one of the key seaports worldwide. But the Rotterdam economy has long outgrown its strong focus on port activities. The knowledge and services economy is also becoming increasingly prominent in Rotterdam. There is considerable competition between various cities in order to retain the knowledge workers that are so crucial for this sector. An attractive residential environment is an important argument for these knowledge workers in their decision for a specific urban region.

S e l e c t i v e m i g r at i o n In Rotterdam, the number of people with a job, a solid education and higher-

Rotterdam has chosen a strategy which focuses on the development of the knowledge and services economy and which provides for an attractive residential and living environment that manages to retain highly trained and creative workers for the city. Such measures have considerable urgency, because the time span within which the city can still benefit from the increase in the working and general population and the related housing demand is short – another 15 years or so.

level income that are leaving is so high that this is insufficiently compensated by the entry and career

The above makes it clear which job Rotterdam has set out for it: over the next few years, the city has to do

development of promising young people. The result is a negative selective migration that has led to an

everything in its power to improve physical conditions and once again make Rotterdam the strong, vibrant

unbalanced composition of the population. To a large extent, the Rotterdammers with a higher education

heart of the region.

do not leave because they want to move out of the city, but because they cannot find the home of their choice in their preferred residential environment in the city. These are important data that can make a

This mission for Rotterdam rests on two pillars: - Strong economy: more employment;

contribution to the reversal of this trend.

- Attractive residential environment: a more balanced composition of the population. working

These two pillars combine to form a single issue: to lead a satisfactory life in the city, you need an attractive residential environment and suitable employment. Employment in turn only develops when a city forms an

walfare

Figure 6. People moving in and -out of Rotterdam

students

attractive business location for entrepreneurs and employers, in which security, trust and good facilities are of essential importance. To form an optimum location (both for companies and people), Rotterdam needs to

retired

both offer an attractive environment and make effective arrangements for security and durability. As was also outlined in Rotterdam Waterstad 2035, in 350 years, Rotterdam also has to be an attractive city for working,

inactive moving out moving in

living and leisure. Or, with respect to the surrounding water, Rotterdam is safe and remains safe.

result Source: COS, nov. 2005

number of persons

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‘Water represents an oppor tunity for Rotterdam’ In addition to tackling flooding in a cohesive manner, Water Plan 2 Rotterdam seeks to provide a long-term vision of water as an opportunity for Rotterdam and the surrounding area. Water can be a real boost to the quality and atmosphere of a district or city, and that makes it an important factor in terms of people’s sense of well-being. This view is also held by Adriaan Geuze, co-founder of the renowned West8 Landscape Architects firm and professor at Harvard University.

People feel happier and more at ease when they live in a recognisable environment – in other words, an environment that is different from

others in vital ways. That is not just the conviction of Adriaan Geuze: it also emerged from many research projects. He believes that this fact,

combined with the need for greater drainage capacity and therefore more surface water, offers an excellent opportunity to make Rotterdam a more

attractive city. One of the areas that is ripe for improvement is Zuid. “There is a historic system of streams that, with a fresh approach, could be given

a more prominent place in the local districts,” explains Geuze, “by making them deeper, for example, and by providing water-related amenities that would make them directly relevant to citizens.” He sees another notable

possibility on the edges of the city in particular, where the water could be

given an important identity function in addition to a recreational one – that of demarcating the city.

“By emphasising the streams in the landscape and giving them more space, a natural boundary will emerge between one region and another. The term ‘across the water’ will then regain some of its significance, and psychologically, that has a positive effect. People like to ‘come from’ somewhere, and also ‘go’ somewhere. They do not want to form part of the common herd.”

How invaluable water is to the city can be shown, he believes, by

Westersingel, Provenierssingel and Heemraadsingel, among others. “These are the places where Rotterdam, the metropolis that it is, can catch its

breath. It is here to where people almost automatically come to, experience peace and quiet, and get some sense of identity. Wherever possible, these are the qualities that should be exported to the areas around the edge

of the city.” He sees more pressing reasons in the social climate (in Zuid,

among other places) rather than in the meteorological one as to why the possibilities should be exploited quickly. “I hope that Water Boards, city

district councils, housing corporations and other interested parties can see

the merits of these ideas for more vital and social living environments, and

that they act jointly to seize the opportunities I have mentioned that water can offer.”

A D RIAAN GE U Z E : ‘ W ATER A S A W EL F ARE F A C T O R ’ 28

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2.2 Radical strategies

Rotterdam has decided to build within the existing city limits. A good business and residential

environment is an absolute prerequisite for a strong city that can grow even stronger. The development of such a strong city within the existing urban area leads to maximum profit for the city and the region. A strengthening of the existing city means making optimum use of the existing facilities. And – at least as important – this decision will ensure that the outskirts of the city are left alone, which means that it will no longer be necessary to realise large-scale developments in areas that are not suited for such construction. By decreasing the ‘housing pressure’ in this way, the recreational and natural functions of the polders and green areas around Rotterdam are maintained and even strengthened. This in turn contributes further to the city’s range of facilities.

The Rotterdam economy demands an attractive residential environment for its highly educated workforce (knowledge workers). Rotterdam has decided to exploit the potential of the existing urban area as far as possible. The decision to use the existing city area focuses on developing attractive residential environments that correspond with the wishes of the housing consumer – something that entails more than just building good homes. It involves linking up with existing identities, interconnecting with the educational offer and other facilities, the quality of the public space, air quality and the basic water requirements!

Figuur 8. creating attractive residential environments by taking maximum advantage of the allure of neighbourhoods

The market demand plays a central role in the development of an attractive residential city. This is

Qu a l i t y - b a s e d ‘ t r i c k l e d o w n ’ e f f e c t The ‘trickle down’ strategy on the basis of quality focuses on

achieved by taking the wishes and complaints of all existing and potential Rotterdam residents in each

creating attractive residential environments by taking maximum advantage of the allure of neighbourhoods

stage of life – young, old, single households and families – as a point of departure. It is difficult to

that function well at present. Cultural-historical heritage and image play an important part in this process.

develop a general picture on the basis of all these different wishes. Nevertheless, broadly speaking we

Existing well-functioning neighbourhoods with a strong identity like Kralingen and Hillgersberg combined

can distinguish three residential environments, for which we can presently see considerable demand

with new construction and restructuring can create a ‘trickle down’ effect, which will in turn have an impact

that will most likely continue in the long term: inner-city housing in central Rotterdam, relaxed urban

on the attraction of the city as a whole.

housing in the neighbourhoods and harbour areas around the city centre, and green urban housing in the suburbs. Rotterdam Urban Vision offers a perspective regarding the development of the existing and new

G e n t r i f i c at i o n o f c i t y n e i g hb o u r h o o ds Gentrification is the process leading to the revaluation of

neighbourhoods towards these three desired residential environments.

an area when existing and new residents and entrepreneurs identify opportunities, unfurl initiatives (new investments and businesses) that prove successful and develop a higher quality environment. Opportunities

To achieve this, we need new strategies that focus primarily on retaining students and higher-level

for gentrification can primarily be found in the old city neighbourhoods surrounding Rotterdam city centre.

graduates in the city:

In those areas where there are indications that there is a possibility of gentrification we will stimulate this process through the sale and consolidation of rental homes and extra investment in the outside space.

- City centre: condensation and improvement - Quality-based ‘trickle down’ effect - Gentrification of urban neighbourhoods

Figuur 9. Strategy attractive residential city

At the same time, we continue with the successful restructuring of post-war neighbourhoods such as Hoogvliet and the rejuvenation of neighbourhoods that have fallen into decay (hotspots) like Spangen.

Rotterdam aims to offer a perspective to all Rotterdammers, which emphatically includes those living in less strong neighbourhoods with a large, vulnerable housing stock. The municipal council, the housing corporations and private individuals will all join forces to proactively handle the problems at hand. The Pact op Zuid agreement is a splendid example of this ambition.

C i t y c e n t r e : c o n d e n s at i o n a n d i mp r o v e m e n t The city centre is important for Rotterdam’s image:

for its residents, but also for tourists and the business community. The centre already has a lot to offer but it can still be improved in terms of identity. One of the ways in which to make central Rotterdam more vibrant is to increase the number of people living in the area. A lot has been done over the past ten years – the development of the Kop van Zuid district, for instance – but this is only the beginning. In comparison with other European cities, central Rotterdam is still extremely under-populated and there is still a lot of space available in the area, with the old port areas in particular having a great deal of potential. In the future, about twice as many people will live in Rotterdam city centre as is presently the case.

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We can only realise a strong economy and an attractive residential city if certain conditions are satisfied in

The primary dams protect the hinterland to the north and south of Rotterdam against high water levels in

the area of public space, water management, infrastructure and the environmental. Indeed, water is one of

the river. Parts of these dams traverse the urban landscape, and other sections are part of the outside space.

the essential conditions of an attractive residential city.

The Flood Defences Act (Wet op de Waterkering) requires the management authorities of the primary flood defences – in this case the water boards and Rijkswaterstaat – to carry out a safety assessment every five

2.3 Water and climate

years. If it turns out that the flood defence or a section of the flood defence no longer meets the requirements, the structure needs to be reinforced. Such improvement measures may claim additional space.

One of the most pressing and visible developments for our present-day surroundings is the global

climate change. Not a day goes by without the media presenting the latest predictions regarding the

For this reason, the water boards have for many years reserved space to accommodate possible

development of the world’s climate. Water is one of the key themes in this discussion. It is clear that over

reinforcements of the defences both today and in the future.

the next decades, we will be dealing with an ever-increasing volume of water. And for Rotterdam, it will literally come from all four corners: from the sea, the rivers, the air and the soil. The water issue, which is

Rotterdam is situated in what is known as Dijkring 14 (Dyke Ring 14). This interconnected ring of

urgent as it is, will only become more prominent.

flood defences encircles a large section of the Netherlands that is home to millions of people and has a considerable economic potential. Indeed, the human and economic consequences of a possible collapse of

The consequences of climate change can already be observed. The heavy rainfall over the past few years (and months) show that the existing water system is already stretched to its limits. Stories about the Noordereiland, which risks flooding as a consequence of an exceptionally high river level, basements that flood due to heavy rainfall and problems with the groundwater levels are of the order of the day. The fire brigade reports and the numerous messages in the different media all testify to this situation.

this defence would be enormous. At present, Rotterdam satisfies the current standards for collapse and flood prevention for nearly all its dyke sections. Dyke reinforcements are being carried out in those sections where they are necessary. For lack of the correct assessment tool, the Parksluizen locks and the sections along the Vierhaven and Merwehaven have not yet been assessed, but this assessment will be rounded off in the course of the plan period.

Map II The primary dykes

The rising temperature will cause the sea level to rise, leading to an increased risk of flooding. The winters will become wetter and the summer dry spells will be longer. At the same time, there will be more and more peak showers, causing more and more nuisance such as flooded tunnels, flooded streets, cellars and basements and more instances of the sewers overflowing into the surface water. As a consequence of the dryer summers, the rivers will drain off less water and the river level will subside. As a consequence, the salt-water wedge will advance further upstream, the quality of the river water will decline and in the long term it will no longer be possible to let in fresh water during the dry summers. If we don’t take the necessary measures soon, there will be more fish mortality and it will be increasingly difficult for the existing green belts and trees to survive the dry summers. And due to the steadily progressing subsidence of the soil, it will become increasingly difficult to deal with the groundwater problem.

S e c u r i t y a n d t h e r i s i n g s e a l e v e l There is no general consensus as to which extent the sea level

will rise. One thing is for sure, however: there will be changes. According to a 2007 publication of the Intergovernmental Panel on Climate Change, the sea level has risen by 18 to 59 centimetres compared to 1990. Between 1993 and 2003, the measured increase was 3 centimetres, which comes down to 30 centimetres per century.

There is considerable debate both in the media and the scientific community regarding the precise level of increase and Man’s contribution to this increase. It has however been established that the sea level will rise. It is therefore advisable to take the necessary measures now rather than wait and see what will happen. If only because an additional rise in the sea level is expected in the period after 2100.

Predictions regarding possible increases in the sea level raise the question to which extent Rotterdam is protected from floods. After all, the security of the various areas both within and beyond the region’s dykes needs to be guaranteed. In an area where a large variety of functions compete for the same space, maintaining a sufficient level of security may not be an easy job, but it is necessary nonetheless. An assignment that can only be successfully executed via a partnership between the municipalities, the water boards, Rijkswaterstaat and the Province.

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economic requirements

Rotterdam faces the task of building a strong economy and an attractive residential environment. The main issue is to increase quality of life in the city and improve the investment climate. To make Rotterdam an attractive place to live, study, work and visit. Water is an important condition for an attractive city, particularly for Rotterdam, which positions itself as a ‘water

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city’. The key requirement of this water plan is to determine how to utilise the various basic water requirements to make an attractive city. Only if we can connect the water requirements to useful solutions that have significance for Rotterdam and the Rotterdammers will the water policy really earn support and will we be able to make a success of its implementation!

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‘Small steps in the right direction’ Former Minister of Public Housing, Spatial Planning and the Environment Pieter Winsemius is known in the worlds of both politics and business as a genuine heavyweight. He is not your typical administrator: he is averse to doctrines and if necessary is prepared to defy convention in an attempt to find new solutions. As far back as the 1980s he succeeded in putting the environment high on the political agenda, and yet he describes the issues surrounding the threat from flooding as ‘reasonably new’. “We don’t have anything like all the answers yet.”

Who is doing what? And who is waiting for whom? When it comes to climate change issues, administrators, businesses and consumers often point the

finger of accusation at each other, while hardly anything actually gets done.

Pieter Winsemius is familiar with these reflexes and is working to promote a joint offensive. “The amazingly fast conversion from leaded to lead-free

petrol is still a source of inspiration to me when it comes to the possibility of bringing about fast and far-reaching beneficial changes. Politicians,

consumers and business people had no trouble joining forces then, and at that time it made a significant contribution to the environment.” In that

particular case the government was just slightly ahead of the game: “There was a sudden changeover, partly because at that time the government

made leaded petrol a little bit more expensive through extra duty, which

also meant that the price of lead-free petrol could be reduced somewhat.”

To combat climate change and to counter water-related problems, he now expects the government to fulfil the same role.

“Where there are commercial incentives, including in the case of environmentally friendly business, governments do not need to intervene. Things will happen automatically. But if you look at investments where the returns as poor, such as with solar panels, then as a government you have to do all you can to send out a signal and have clear and reliable incentive policies.”

Rather than in individual initiatives, Winsemius has faith in a collective

awareness that should continue to grow and then be translated as quickly

as possible into action. “Here in the Netherlands, there are programmes like ‘Room for the River’, and the Ministry of Public Housing, Spatial Planning and the Environment will also shortly be bringing out a new water

management plan. These are all useful developments. But the realisation

that the Netherlands is seriously under threat is still reasonably new from a historical point of view. That realisation has to grow. The only thing you can do now is help accelerate this process by emphasising the urgency

of the situation.” Until that ‘great breakthrough’ comes, Winsemius, as a

pragmatic man, will continue to push for what he calls ‘small steps in the right direction’. “I see Water Plan 2 as just such a step.”

Pieter Winsemius 36

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B o x II - R i s k a p p r o a c h R i s k s a ss o c i at e d w i t h f l o o d i n g Residential districts of Rotterdam that lie outside dykes are built at a very

By using this approach, the construction of very high banks can be avoided in the design and development of areas

above sea level, but the actual height depends on the chance of flooding. At present it is assumed that residential

towns: less sensitive features of the area, such as parks, can be exposed to greater risks of flooding and are therefore

high elevation in order to prevent their being flooded by the river. In some cases they are even four to five metres

areas should not be subject to flooding more than once every 10,000 years. However, we are starting to realise that

‘the chance of flooding’ does not actually mean very much. It is much more important to look at the possible risks to people, buildings, infrastructure, etc. For example, the situation that arises when water cannot escape after a flood,

such as in the case of a polder, is different to that of areas that lie beyond dykes. The disaster in New Orleans is a case

in point. It is therefore time for a risk approach to flooding, all the more so given that forecasts about rising sea levels are still uncertain.

Th e ta s k Up to now it has been the case that when an area located outside dykes is being developed or redeveloped,

one factor that is considered is the acceptable level of risk of flooding. For residential areas this means that the river

beyond dykes without the safety of such areas being under threat. It can even open up opportunities for attractive more suited to lower-lying land than are sensitive features, such as residential areas or major traffic arteries. This

means that towns in areas outside dykes can be tailor-made – the water can play a prominent role in the quality of the surroundings without undermining safety.

The lack of certainty in the predictions of future water levels requires a flexible approach to and design of these areas, which can grow even as water levels rise, whether they are 20 cm or six metres. This calls for innovative

concepts for these areas in the form of modified buildings that can be made watertight, new design layouts, or banks with flexible damming capacities.

water can flow over the dykes once every 10,000 years, with the expected rises in sea levels taken into account. At the

W h at i s a n a c c e p ta b l e r i s k ? At present, it is not clear what constitutes an acceptable risk when it comes

areas will be too low or too high. The task facing Rotterdam is to develop new areas outside dykes in such a way that new

at which this theme is being discussed. One option being considered is the introduction of a minimum level of

same time predictions about the climate developments are uncertain and it may well be that in a few decades, these

residential environments are created by the water. The rise of water levels should be factored into the developments and they should be safe. It is important that they are designed to cope with the risk of flooding as well as the uncertainty of the rise in water levels and, at the same time, that the environment created is an attractive one.

The risk approach in relation to building in areas outside dykes entails the examination not only of the chance of the area becoming flooded but also the consequences of any such floods. This is shown in the illustration below. The risk in this

approach is defined as the possibility multiplied by the consequences. The essence of this is that we find it acceptable for an area to be flooded from time to time provided the damage to persons and property (the consequences) is limited.

Conversely, if the potential damage is great, then the chance of flooding occurring should be very slight.

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to building in areas that lie beyond dykes. Consultations on water safety are currently underway at provincial level protection, while another possible basis for determining acceptable risk could be that it is set at an equivalent level to the risk faced by areas that lie within dykes. Water Boards are responsible for water safety in the areas inside the

dykes, but in the case of areas under development outside the dykes this lies with the parties wishing to build there.

The position in relation to existing areas is not entirely clear. It can be assumed that no immediate, life-threatening situations will occur because the level of the water will never rise that much anyway given the elevated nature of

the location. The level of acceptable risk is therefore determined by the extent to which the damage is covered by

insurance. A great deal of experience has already been gained in this area in some countries, where the greater the

risk is, the more expensive the cover. If the risk becomes too great, it automatically becomes more attractive to take measures to reduce the level of risk or limit the damage.

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safety requirements

Rotterdam also needs to be protected from high water in the long term. This means that a further reinforcement of the primary and regional flood defences is inevitable. We must already start reserving space for these measures today, taking the water levels into account that can be expected in 2050 and 2100. According to the current norms, the primary flood defences need to have the required height by 2010. For the regional flood defences, the target date is 2015, with a possible extension until 2020.

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In the area outside the dykes, the present structures and layouts need to be analysed with the help of risk calculation, taking account of both their lifespan and the climate change. This can result in measures being taken to protect against or limit the damage as the result of flooding. This project includes the elaboration of a communication strategy.

For new development projects in areas outside the dykes, the risks will be weighed in advance through use of risk calculation.

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It has since turned out that the Maeslantkering storm surge barrier does not meet the existing norms

As a consequence, there are insufficient guarantees that inundation of the areas outside the dykes is ruled out

with regard to risk of failure. The effects of a possible failure on the water defences and the area outside

as stipulated in the security policy. This will possibly have consequences for the height of the primary water

the dykes behind the Maeslantkering were published by Rijkswaterstaat in late 2006 in the report

defence along the Nieuwe Maas waterway. In addition, this complex discussion with enormous potential financial

‘Achterlandstudie Maeslantkering’. Although the risk of failure is theoretical and involves a wide variety of

repercussions also takes the design lifespan of the Maeslantkering into account. This means that we already have

factors, the issue can primarily be traced back to the software used to operate the barrier. Nevertheless, the

to make decisions at this point about the strength of the defences, granting altitudes and construction outside the

fact remains that this means the barrier falls short of the safety requirements.

dykes in fifty years time and beyond.

The above information will be incorporated in the Water Safety Programme, which is coordinated by the

Map III Inundationmap

Province of South Holland and represents a variety of parties, including all the water plan partners. This programme will deal in general terms with the question whether the low-lying part of our country will remain inhabitable in the longer term and – following from this question – the shift in public attitudes towards security risks. What is still acceptable, and what is the government’s role in this all? Communication about the risks and possible measures against these risks play a key role.

D r a i n a g e e mb a n k m e n t s a n d p o l d e r d y k e s Drainage embankments are regional flood defences (dykes)

that protect polders from inundation from the canals and large waterways. The Province of South Holland has established security norms for the regional embankments. These norms indicate which level of security the drainage embankments have to meet. The next step is to assess whether the drainage embankments fulfil the set criteria. The first assessment report on this matter is expected to be published on 1 January 2009. The embankments in question subsequently have to be ‘in order’ in terms of safety by 2015. This is a target date, with a possible extension until 2020.

A risk calculation (risk = possibility x consequence) is used to determine the safety of a drainage embankment.

For each polder, this assessment reviews the height of the damage caused by possible inundation: what are known as the security classes. These security classes determine which investment is subsequently made in protection. For instance, in a particular case the polder may have a higher building density, which increases the damage (costs) should the dyke give way. In this case, the security level of the polder needs to be enlarged, and the parties that initiate the building plans need to take dyke reinforcements into account for example (the cost driver principle). In view of the considerable interests involved, it is therefore essential to involve the Municipality in such evaluations (both the risk calculation and the possible consequences). This means that in Rotterdam too, the Municipality needs to take a keener interest in its role and responsibilities and the activities that are possibly required on the basis of this position.

Similarly to the case of the drainage embankments and polder dykes, more and more attention is paid to the potential risks of an inundation. This means that besides reducing the possibility of a flood, there is also the option of design measures in the area outside the dykes that limit the damage caused by an inundation or offer the possibility of an evacuation at all times (in other words, restrict the damaging effects of an inundation).

This makes the flood risk more controllable and attunes it to the local function. However, it is an essential condition that responsible choices are made and that the communication on this subject is completely clear and transparent.

A r e a o u t s i d e t h e d y k e s The areas that lie outside Rotterdam’s dykes are among the highest-lying parts

of the city. Due to their relatively high altitude, these areas usually do not require the protection of a dam.

Certain measures are necessary to keep it this way, however. With the increasing pressure on public space and Rotterdam’s unique location on the Nieuwe Maas waterway, over the next few years there will be a growing demand to start building outside the main flood defences. With its adapted line of policy for the Major Rivers, national government has also opened up the possibility of building in the rivers’ winter bed, on the condition that the river water can be stored and drained off safely. The primary flood risk for areas outside the dykes lies with the area developer. In Rotterdam, the Public Works Department bears responsibility for determining the granting altitude. A high granting altitude does however entail extremely high development costs, in connection with the high costs involved in raising a building location.

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‘ The technolog y is there. It is costs that are a problem. ’ Good sewerage systems extend our life expectancy, protect the environment and help combat infectious disease, but as a subject, they are not particularly sexy. As the director of the Rioned Foundation, the Netherlands national centre of expertise for urban sewerage systems and water, Hugo Gastkemper should know. The tasks associated with sewerage systems are wide-ranging, the financing is complex, as is the field of legal responsibilities between government and citizens. Nevertheless, the general policy line for the 21st century is clear: ‘more room is needed for water due to heavier downpours of rain.’

As an ‘average citizen’, how often do you stop to think about drainage? And do you wake up in the morning with an image of a sewerage tunnel in your mind’s eye? Not very often – in

fact, probably never. In spite of this, Hugo Gastkemper is attempting on behalf of Rioned to

move the subject higher up the political and business agenda by, for example, drawing their attention to the www.riool.info website, where the general public can access a great deal

of vital knowledge and information on the subject. Although the technological aspects of

sewerage systems are largely the responsibility of local authorities, and a report by Rioned

suggests that performance levels understandably vary, there is agreement at national level

as to how things should be in the future. Gastkemper says, “Climate change means that the

focus will have to shift towards measures designed to control rainwater temporarily and in an environmentally friendly way instead of just pumping it and draining it away.

“During those few crucial periods a year when there is an extremely high amount of rainfall, the essential question will no longer be about how we keep our feet dry but rather, how can we manage water in such a way that flooding and damage to the environment are kept to a minimum?”

There is after all a direct link between how rainwater is processed and drained and the

quality of water, which according to Water Plan 2 Rotterdam also has to comply with the guidelines of the European Water Framework Directive. “The technology for draining

polluted water and rainwater separately is of course already in place,” says Gastkemper, “by draining it through two different pipes, for example. However, the problems revolve

around the existing urban structures, the costs, and the possible pollution of rainwater.”

As far as setting priorities is concerned, Rioned is for the moment looking at keeping

existing sewerage systems in the Netherlands up to scratch. When they are replaced, as many measures as possible are taken to combat flooding and to improve water quality.

Gastkemper continues, “A large proportion of the present sewerage systems were built in the 1960s and 1970s, and now need to be replaced. That is the reason why considerable increases in the sewerage taxes are inevitable, across the whole country.”

Nevertheless, the first signs of this ‘new thinking’ about dealing with excess water are now visible – in Rotterdam, for example, on Westersingel, where an urban flood plain serves as a catchment area when there is heavy rain. “The Water Plan 2 Rotterdam

contains the city’s cohesive vision on the water management challenges of the near and

more distant future,” says Gastkemper. “That is progress. Now it is time for action. I hope that Rotterdam will take it.”

H u go G astk e m p e r : ‘ D O N ’ T J U S T P UM P I T – C O N T R O L I T ! ’ 46

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P r e c i p i tat i o n a n d f l o o d i n g Due to climate change, there will be more frequent and increased amounts

of rain. In addition, the sea level will rise, which will steadily increase the difference in altitude between the River water and the drained polders. In order to adapt the existing water system to these changes, the national government, the Provinces, the Municipalities and the water boards signed the National Policy on Water Management for the 21 st Century (NBW) in 2003. The main objective of this agreement is to have the Dutch water system in order by 2015.

Kaart IV Water retention shortages present situation (2015) and 2050

Over the past few years, the water boards have made various calculations focusing on the basic water requirements in 2015 and 2050. These concern the cubic metres of extra water that need to be accommodated by the surface water system. Analysis of the existing water system tells us that there is a shortage of storage facilities throughout virtually the entire city. A total of some 600,000 m³ of extra water storage facilities still have to be realised in Rotterdam’s urban area between now and 2015. And with the expected impact due to climate change, in the long term (2050) this requirement even rises to a total of 800,000 m³.

Map IV Watersystem

Incidentally, it is appropriate to make certain differentiations with regard to these figures: they are the outcome of theoretical calculations (according to national agreements) for the surface water. In practice, this means that

If the system is not in order and the water courses cannot accommodate the water in the event of extreme

in the urban area, the wastewater collection system will drain off the lion’s share of the precipitation. Particularly

precipitation, this will lead to flooding. This will be observed in the overflowing of the canals and the

in Rotterdam, where the wastewater collection system and the surface water system are interwoven and a large

wastewater collection system. Besides causing economic damage, this also poses a threat to hygiene and public

percentage of the rainfall is drained off directly into the Nieuwe Maas by means of the overflow drainage system, the

health and to the safety of the population.

actual basic water requirement will be considerably lower (although we have to realise in this context that this will create additional problems for storage within and before entering the wastewater collection system). Furthermore,

F l o o d i n g f r o m su r f a c e w at e r ( t h e b a s i c w at e r s t o r a g e r e q u i r e m e n t s ) It has been agreed in

the Rotterdam Water Plan 2000-2005 and the district water plans already include heavy investment in measures

the National Policy on Water Management for the 21 st Century (NBW) that flooding in urban areas may only occur

to make the water system more robust and to realise more storage facilities, which already takes care of part of

a maximum of once every 100 years. The related basic requirements calculated by the water boards in this context

the basic water storage requirement. It remains a fact, however, that the basic water storage requirement faced by

are known as the current quantitative or basic water storage requirements. These basic water requirements should

Rotterdam is still quite substantial, both for the period until 2015 and for the longer term.

be realised by 2015. The solutions that are developed in this context need to be durable and robust. Preferably, water should initially be retained in the urban area, and if this is impossible it should be temporarily stored at

These required volumes of extra open water lay an enormous claim on the available space in the city.

other locations (for instance via the development of extra water areas). Only if there are no other possibilities

Particularly in dense urban areas, it is virtually unfeasible to dig basins for the required open water, but

to accommodate the water should it be drained off. Accommodating the precipitation for a longer period at the

in less densely populated areas too these projects will result in major complications, not to mention the

location where it falls ensures that the existing water and wastewater collection system are not overloaded.

expenditure that they involve. It is already clear at this point that the responsible parties will have to utilise alternative and innovative solutions for the basic water storage requirement. The calculations for the basic

In addition, the NBW also contains the agreement that solutions need to take the impact of climate change

water storage requirement are based in part on the impact of the wastewater collection system. In the course

into account. The extra water measures required for this need to be in place by 2050.

of the Rotterdam’s Water Plan 2, the calculation of this factor will see further refinement.

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wat e r r e t e n t i o n r e q u i r e m e n t s

In view of the current climate change, we have to prepare ourselves for large volumes of precipitation within short time stretches. In order to effectively handle this rainfall, we need to be able to temporarily accommodate and store the water within the city limits.

Based on the forecasts, we currently assume that if the entire volume had to be accommodated in the surface water, these storage facilities could handle some 800,000 m2. If we look at the storage capacity of the current surface water system, there are presently insufficient storage facilities. Calculations made by the water boards indicate that the volume involved is some 600,000 m2. At the national level, the authorities have agreed to have realised these basic storage requirements by 2015. In practice, a large share of the 50

excess water will be drained off via the wastewater collection system, which will incidentally lead to problems in the sewer system during peak incidents (intensive flash downpours). A portion of the basic water storage requirements have already been realised in the implementation programme of the Rotterdam 2000-2005 Water Plan, the district water plans and the municipal water plan.

The various parties nonetheless still have a lot of work to do. In view of the city’s specific urban design, we have to actively seek out new ways to realise extra open water in development projects. In addition, we need to strongly commit ourselves to developing alternative and innovative water storage solutions.

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S e w e r a g e a n d f l o o d i n g ( t h e b a s i c u r b a n w at e r r e q u i r e m e n t ) The Municipal Sewerage Plan

S e w e r a g e a n d p r e c i p i tat i o n The city’s wastewater collection system has a direct connection with

2006-2010, which sets down Rotterdam’s sewerage policy for the coming years, was approved by the

the city’s water system. Due to the nature of the wastewater collection system, an impact on the water

municipal council in 2006. This plan establishes the city’s basic wastewater management requirements,

system is inevitable. In contrast with the rural area, the rainwater in the urban area in the event of heavy

which are closely linked (in terms of water storage and water quality) with the basic water requirements as

precipitation is primarily directed to the surface water via sewer overflows. This has its consequences for

reviewed and indicated in the underlying Rotterdam Water Plan. In addition, the Sewerage Plan maps out

both the quality and the quantity of the surface water. The quality of the drainage water, the frequency

what the financial consequences are of the proposed policy. This makes the Municipal Sewerage Plan an

of the overflows and the volume and quantity of the surface water that accommodates the effluent are

important pillar of this water plan.

all determinant for possible negative effects. The insight that the precipitation is not clean 100% of the time either, in combination with the risk of faulty connections, led to the decision to develop an improved separation system in the sewerage, which directs the first share of the precipitation to the treatment plant.

One of the consequences of this system is that each year, an average of 70% of the rainwater is pumped to this treatment plant.

In general, the drainage from a wastewater collection system with improved separation is less detrimental to the quality of the surface water than overflows from a mixed or, in some cases, a separated wastewater collection system. The decoupling of hard surface is an even cleaner solution. In addition, the sewerage overflows cause the level of the surface water to rise, which can lead to inundations.

Furthermore, the drainage of precipitation via the wastewater collection system makes heavy demands on the wastewater treatment plant (RWZI). This facility operates best under dry weather conditions. Major fluctuations in the volume of water to be treated due to the extra volume of relatively clean rainwater have a negative effect on the plant’s purification performance and are determinant for the RWZI’s maximum hydraulic capacity. If this capacity needs to be increased to handle the supply of extra rainwater, this can result in enormous extra costs.

And finally there is the issue of flooding, which was also referred to in the section dealing with the basic water storage requirement. If the surface water rises to such a level due to excessive precipitation that overflow from the wastewater collection system becomes impossible, the functional integrity of the collection system itself is threatened. This can result in water seeking its own way out of the sewers via storm drains etc, leading to flooded streets (and even to overflowing bathroom facilities in basements if they were installed incorrectly). This poses a possible threat to the city’s hygiene and public health. This is another reason to make sure that the capacity of the storage facilities in the surface water system is sufficient and makes the successful realisation of the basic water storage requirement all the more urgent.

In other words, another precondition of the basic water storage requirements is that they are taken on in conjunction with the wastewater network requirements. This water plan works from the principle that in m³, the storage facilities provide an adequate solution for the basic storage requirements relating to both the surface water and the wastewater collection system.

The main points of the Municipal Sewerage Plan are as follows: - The length of sewers that is replaced every year has to be increased substantially (from 14 km in 2000 to 40 km in 2010) in order to ensure and even improve the working and quality of the wastewater collection system.

- The introduction of the Central Automated Control System (CAS) for the wastewater collection system allows for better distribution of the wastewater throughout the wastewater collection system, which has a major positive impact on the system’s capacity to store water (thus limiting the risk of sewerage overflows) and deliver it to the treatment plants.

- In accordance with national agreements, all untreated discharges (from buildings that do not yet dispose of their effluents via the wastewater collection system) need to be restructured – commonly referred to as the duty of care. Except for specific situations in which the Municipality has granted dispensation, this restructuring will be rounded off in the current period, after which nearly 100% of the local buildings will

Clean, clear and ‘usable’ surface water within city limits requires the wastewater collection system to have a minimum negative impact, as well as demanding a new approach to handling precipitation. At the same time, we are aware that the wastewater collection system serves an important objective, namely the hygienic and speedy disposal of our wastewater for the benefit of public health. Ensuring that the wastewater collection system has a minimal negative impact on the water system involves bringing the discharge of wastewater via the wastewater collection system back to the very minimum (both in terms of frequency and volume), minimising the proportion of pollutants in the effluent (quality) and arranging sufficient storage capacity to accommodate the drainage water (limiting the level increases).

be connected to the wastewater collection system.

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Sewerage requirements

In addition to the challenges as set out in the Municipal Sewerage Plan 2006-2010 (GRP2), relating to sewer replacement, basic efforts and sewerage connection, there is also the additional task of reducing and where possible preventing flooding.

To develop durable solutions for these targets, the key issue is to prevent dirty and clean water streams from becoming mixed.

For a healthy city, wastewater needs to be purified in wastewater treatment plants and clean rainwater needs to be treated 54

alternatively and/or drained off. Furthermore, in order to prevent peak overloads in the water drainage system, it will be necessary to retain precipitation and slow down its drainage. Combined with an ample volume of surface water (extra storage) these measures can prevent inundations and long periods of flooded streets, i.e. wet feet.

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‘It star ts with a little puddle …’

The famous owner of a Rotterdam hairdressing salon, Daan Brakman, is passionate about his business and life away from work. When he was affected by flooding he remained unruffled and courteous, and entered into ‘honest discussions’ with Public Works and the Water Board. “I played a small part in helping to build bridges – and to find solutions.”

The Brakman hairdressing salon on Westersingel is exactly the kind of

atmospheric place where people can drop by that every city needs so badly.

The business moved a few years ago from one metre below the level of

the canal to one metre above it. It was because of repeated flooding that

Brakman decided to relocate from Mauritsweg to the other side – that is, to Westersingel, where he is now happily running his business. Although he is now in a safe spot, as co-founder of the Wateroverlast Rotterdam Centrum (Rotterdam City Centre Flooding ) residents’ group he still feels involved

with the problems associated with drainage. “Here,” he says, and produces a collection of photographs showing his previous salon when it was flooded.

“Do you see this customer? He’s waiting his turn to have his hair cut and he’s looking bewildered at the rising water at his feet. Imagine: at first

there’s just small puddle in the corner, and half an hour later the whole place is under ten centimetres of water!”

Brakman remembers how hard the pumps had to work in order to get

everything back to being presentable again, and how he then got in touch with Public Works and the Water Board for “an honest person to person

discussion” in an attempt to improve the situation as quickly as possible.

Brakman continues, “If you approach people in a friendly and constructive way, they will always be ready to listen. That was the case here, too.”

Although it quickly became clear to Brakman how complex the matter was, he and his two partners continued to push for an improvement. “Somehow

or other we had to get the capacity increased of the pumping stations that pumped the water towards Westzeedijk, so that in the short term it would be possible to transfer more surface water from the canals to the river.

Putting such a solution into practice took some doing, but I am glad the situation has now improved.” Brakman points outside, to the wonderful statues on Westersingel and says with pride, “The chances of the water from the canal reaching those statues have dropped considerably.”

It is the very ambition to improve the working relationship between the various administrative bodies, and to intensify the links with project developers, housing corporations and water boards in Water Plan 2

Rotterdam that Brakman is so pleased about. “I am by nature someone who tries to build bridges. We can only control water by acting in unison. That is the lesson I have learned from my own experiences here.”

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g r o u n d wat e r r e q u i r e m e n t s

Rotterdam has a directing role vis-à -vis groundwater issues in the existing area. In this activity, groundwater-related nuisance for the Rotterdam citizens is the primary focus, not the management of groundwater in the urban area. The interests of the citizen as residential consumer are balanced with those of the citizen as taxpayer. The citizens’ own responsibilities in the case of groundwater issues need to be communicated clearly. If it is decided that the government will take measures to deal with excess groundwater, the Municipality will bear responsibility for draining it off and 58

the water boards for subsequent drainage. The costs of draining it off can be covered by expanding the sewer charges to become what is referred to as a water levy. In the case of newly developed areas, Rotterdam in its role as director of the urban design plans needs to ensure that the site and the buildings are structured in such a way that they meet the requirements of the local water situation and groundwater situation, or take the necessary measures to prevent excess groundwater.

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D u t y o f c a r e f o r g r o u n dw at e r Both the water boards and the Municipality are facing changing

The drainage system for the Netherlands’ main rivers is set to change as a result of the high levels of

responsibilities with regard to the handling of groundwater, as set down in the Parliamentary Act on the

precipitation in the winter and the summer dry periods. The calculations for the Maas River are based on

Anchoring and Budgeting of Municipal Water Tasks (Wgw). As of 2007, municipal councils have duty of

the peak drainages, which will be more than 150% higher than the present situation. For Rotterdam, the

care for the effective collection of excess groundwater. This does not mean that the Municipality becomes

changed river drainages will have a limited quantitative effect – except for the shipping sector. In this area,

the executive agency responsible for managing the groundwater, but rather that the Municipality becomes

the sea will have a bigger impact than the river level. Consequently, the basic requirements in this area are

the formal point of contact (desk function) for groundwater-related issues. Rotterdam will have to serve

essentially the same as the basic security requirements.

as a link in the chain and determine the best approach to groundwater-related issues in consultation with other government authorities, companies and private individuals. Because neither local government nor other authorities are necessarily the parties that have to take the required measures. Citizens have their own

2.5 Water quality

responsibility: they are required to deal with groundwater problems in their own homes and on their own

premises and only if this can no longer in fairness be required of them will the government step in. In these

cases, the Municipality will ensure that the water is drained off to the surface water and the water authority

substances (an extensive list of parameters that is included in the European Water Framework Directive,

takes care of the drainage via the water system.

the WFD). Although it has not yet been established that the norms for these priority substances have

The water quality in Rotterdam is substandard. There is little information with regard to priority

been exceeded in Rotterdam, there are enough substances present that do not meet the national criteria: Detailed studies of instances of excess groundwater are often handled by government bodies and are subject to

chloride, heavy metals (copper, nickel, zinc), nutrients (particularly phosphate), oxygen and pesticides. In

coordination by the Municipality. The Municipality subsequently determines what needs to be done, as it is the

addition, many waters have a poor to substandard ecological quality and do not meet the ecological targets

responsibility of the Municipality to balance the interests of the individual resident with those of the taxpayer.

set out in the WFD. The Rotterdam swimming water areas occasionally have problems with algal bloom,

After all, the taxpayer is the one who will ultimately foot the bill. The Municipality will gain the option to fund

leading to excessively murky water. With the increasing pressure for multifunctional use of space (living

the costs of such an approach from the sewage charges. To this end, the sewage charges will be ‘expanded’ to

on the water, leisure activities, etc) and the performance requirements ensuing for the European Water

become a water charge.

Framework Directive, local authorities will have to make substantial investments in the water system in the years ahead in order to improve its general and ecological quality.

In new development areas this also means additional responsibilities for the Municipality. As the party directing the urban design programmes, the Municipality has to ensure that the site and the new buildings

By now, knowledge on the subject of water quality has advanced considerably. The Bergse Plassen and

are structured in such a way that they meet the requirements of the local water and groundwater situation.

Zuiderpark projects have proven that we can achieve visible success with an integrated approach to the

Rotterdam cannot and will not guarantee a specific groundwater level. This is because in urban areas in

entire range of issues. In addition, various studies show that with a modest effort, we are able to visibly

the Western Netherlands, this level is dependant on a wide range of factors and there is simply insufficient

improve the quality of a large portion of the surface water. An important development in the ideas

knowledge in this field at present. Rotterdam has decided to adapt the utilisation of a specific area as far as

surrounding the required approach is a central focus on the ecological end result.

possible to the characteristics of the groundwater system (function follows level).

2. 4 Drought and water shor tages

The dry summers of 2003 and 2006 have shown us that we should not only take an interest in excess

water, but that the lack or poor quality of water and groundwater can also create problems. Extended dry spells and excessively dry periods can lead to more saline seepage and to the deterioration of the urban surface water.

To maintain the quality of the water at a certain level and to counteract the influence of possible extra saline seepage, it is necessary to supply extra water to flush out the system. A possible solution lies in the realisation of seasonal storage facilities. Seasonal storage in an urban area can hardly be realised by developing large-scale ponds (in addition to the amount of space this would require, the ponds themselves also demand a great deal of water in dry periods). The solution is sooner found in flexible water level management, in which the policy will be to allow for a higher level during wet periods and a lower level during dry periods. In addition, it is important to realise sufficient capacity in the system’s connections with the regional water system.

Due to the rising sea level in combination with reduced river drainage in the summer, in the long term the saltwater wedge in the Maas River is expected to move further upstream. This shift can contribute to extra saline seepage in the polders. Furthermore, the advancing salt-water wedge will reduce the opportunity to let in water from the Nieuwe Maas and the waterways. Thanks to the option of seasonal storage by means of flexible water level management and capacious connections with the regional water systems, less water will have to be let in from these sources and it will be easier to let in fresh water from admission points that are less influenced by the changing salt water regime.

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w a t e r sh o r t a g e r e q u i r e m e n t s

In order to also guarantee that Rotterdam has sufficient water of sufficient quality during dry spells, we need to respond to this development by realising seasonal storage on the basis of flexible level management. In addition, there need to be sufficient capacious connections with the regional water system in order to be able to let in extra fresh water.

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The policy for the next few years will primarily be determined by the European Water Framework Directive (WFD). The WFD sets targets to ensure that the surface water and groundwater will have a healthy ecological and chemical condition by 2015. The implementation of the WFD is the joint responsibility of all water management authorities in the Netherlands. While the standardisation method is set down in the Directive, the standards themselves are established by the water management authorities themselves in consultation with the municipal council, within strict guidelines. This is a fixed-result arrangement that involves hefty fines should the responsible agencies fail to meet the mandatory targets. In addition, this Framework Directive can have consequences for building projects and district designs, in view of the fact that a deterioration of the general and ecological quality of the water can possibly result in legal disputes analogous to the current issues relating to airborne particulate matter.

The WFD stipulates that the member states have to identify what are referred to as water bodies. These water bodies are sections of the total water system of a certain size or a certain drainage system. The responsible authorities are held accountable for these water bodies. A number of water parties have been designated water bodies in Rotterdam. Water quality targets are drawn up for these water bodies according to a predetermined methodology. If the current water quality does not meet the requirements, the responsible authorities have to indicate to which extent it is possible to reach the target with specific measures and the related financial and other consequences.

In the Rotterdam Water Plan 2000-2005, the water quality objective was formulated in three target images, namely the ‘compact city’, the ‘blue ring’ and the ‘green wedges’. The advantage of this approach is that the objectives were linked to the city’s spatial arrangement and that the terms were easy to use, as was evidenced by their swift distribution and widespread familiarity. The advancing insight into water quality and the key mechanisms that underlie it, combined with the mandatory methodology as prescribed by the WFD have however forced us to let go of these target images as they proved to no longer be feasible.

Map V Waterbodies European Water Framework Directive

Parallel to, and in anticipation of the methodology as it is prescribed by the WFD, in the underlying water plan we have adopted a new approach in order to map out and improve the present water quality and the related ecosystem. Taking our lead from a study focusing on a rural area that was carried out by the Polder Board of Schieland and Krimpenerwaard, we will be working in Rotterdam with what are known as water quality images. A water quality image can vary per water type (which is in part location-dependent).

Our ambition focuses on clean water with a wealth of vegetation. Map VIII shows which water types presently fit the definition of ‘clean, plant-rich water’.

According to the various studies, the physical structure of the different water bodies proves a major factor for local water quality. The depth, bank revetment and robustness of the system all act as codeterminants. But fish also have a crucial impact on the local water quality and ecosystem. This is why we will also draw up comprehensive fish stock management plans with the accompanying measures. All in all, it can be concluded that there is a lot of work to be done in the area of water quality and ecological issues, but that by adopting the approach outlined above, we are sure to achieve results. Which will bring us closer to our final objective: an attractive water city with clean, clear water that we can view with enjoyment, relax by and fish in.

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DECISIONS OF CRUCIAL IMPORTANCE In the previous chapter we provided a detailed description of the requirements we are facing. We also described some of the solutions we are aiming for. But in order to realise them whilst at the same time arriving at an integral vision for the area (and the implementation programme that goes with it), choices have to be made. In this chapter we describe the points of departure for Rotterdam Water City, the so-called ‘Decisions of Crucial Importance’.

These choices are not all on the same level, nor are they all equally specific; this would in fact be impossible, given the complexity of the basic water requirements and their connection with our basic urban requirements. But in our view they are the choices that need to be made if we are to produce an ambitious but nonetheless realistic vision and the necessary implementation programme.

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3.1 Protecting Rotterdam now and in the long term

The extent of the future impact of climate change on Rotterdam has been referred to several

times. Higher rainfall, but also more drought, higher sea levels and higher river outflows will all affect the city. The exceptional summer of 2006 was perhaps a portent for the future: an extremely hot summer coupled with torrential rainfall.

The ICCP has already produced initial forecasts of greenhouse gas emissions and their consequences for the Earth’s temperature and the melting of the ice caps. The extent to which this climate change will continue is still disputed, and the extent to which man is influencing it is set to be the subject of discussion for a long time to come. One thing is certain, however: the climate is changing, and being a city on a river and near the sea, Rotterdam must be prepared.

Rotterdam must be permanently protected against flooding, both inside and outside the dykes. All quays and dykes that are not high enough will be reinforced by 2010 (primary defences) and 2015 (secondary defences). But we also need to think about our future safety. It goes without saying that we need to set aside the necessary space for raising the water defences. But this does not necessarily mean that the dykes of the future will form massive barriers between the city centre and the areas being developed outside them. Water managers and urban developers will work together to design the dykes of the future as connecting elements, so that our water defences can be used as park landscape, a balcony on the Maas, or footpaths or cycle routes - in other words, combining functions while at the same time ensuring our safety.

The core concept in the issue of safety is ‘adaptive strategy’. A strategy in which the city adapts to changing circumstances. One in which we set aside the space we will need for future water storage now. Or in order to improve safety, one in which the projects we will need at some stage in the future are prepared now, and one in which we come up with innovations now which we can use later. And where the opportunities arise, we must take steps now, even if their effect will only be felt in the longer term.

With regard to the area outside the dykes, Rotterdam is playing an active role in respect of the province, which is involved in drawing up safety standards. Building outside the dykes is a huge opportunity for Rotterdam. Some extremely attractive residential environments are being created, and as long as we make allowance for possible future river water levels in designing these areas, safety need not be an issue.

This can be done by raising dykes, but more innovative methods could also be developed. We will need to create space for new residential environments in areas outside the dykes, such as floating homes or floating surfaces.

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‘De randstad region as a save stronghold’ During his famous speech on climate change, Al Gore recently flooded the entire Randstad conurbation of the western Netherlands with the flick of a switch - in a virtual sense, naturally. “Nevertheless it was a sad moment,” says Piet Dircke, Water Programme Manager at Arcadis, the international firm of engineers. “We have to fight that future scenario tooth and nail. The Randstad is too important to the Netherlands and its landscape is too special.”

Ministers, senators, CEOs, mayors – water expert and lecturer on Urban Water at Rotterdam University Piet Dircke has already held discussions with many decision makers. One of the lessons that he has

learned from his worldwide experience is that managing water is not just a matter of technology, but that there is also an emotional dimension.

“I found the point when Gore allowed the blue of the sea to flow over our Randstad region very regrettable. We should not underestimate the ability of that kind of picture to have a knock-on effect. I’ve heard, for example, that some companies would no longer want to have their head offices located in the Randstad, because they are afraid of the risk of flooding. That’s how economics and emotions can have an adverse affect on each other.”

In New Orleans, too, Dircke has experienced only too starkly the emotional aspects of water. “The

disaster with Hurricane Katrina reaches far beyond the suffering of individual victims. A serious breach

of trust has emerged between citizens and government, which will be very long lasting. The people there were not prepared – and in fact neither was the government.” The fact that Dutch companies and aid

missions are currently being welcomed with open arms in Louisiana also has an emotional background, believes Dircke. “Just after the disaster the Americans felt that we, the Dutch, had not come simply to help out, but that we had ourselves experienced what the consequences of flooding were. They were

able to see that we could empathise with their feelings of powerlessness. That ultimately made a deeper impression – among officials, too - than the lead we enjoy in terms of knowledge.”

Precisely because the emotional scars left by flooding and other problems caused by excess water run

so deep, Dircke is a passionate advocate of rigorous safety policies. “For the Americans it is a revelation to learn of the level of cooperation in the Rotterdam region, for example: that is, between local

authorities, provincial governments, the Port of Rotterdam, the Water Board, Rotterdam University,

consultancy firms and other parties. They look at the Delta Works with great admiration and say, ‘Can

you not build something like that for us?’, without realising that, like the Maeslantkering storm surge

barrier, the Delta Works form the final piece of an integrated vision of safety, environment, landscape, recreation and economics.”

He is relieved that the increased awareness in the Netherlands regarding the climate is currently leading to even more attention being paid to the storm surge barriers, and that the budgets for

improving dykes and innovative technology in the field are again being expanded. Take the recent

experiment involving a ‘digital dyke’, for example – it was not only inspected visually, but also from within, using sensors in order to locate possible weak points quickly and accurately. Dircke says,

“Projects like that send out a signal that we are not going to give up the Randstad – that we’re here to stay! In addition, as we gradually move further into the 21st century, 70 to 80 per cent of the world’s

city dwellers will be living in deltas, so from an economic perspective our knowledge of water will only become more and more useful.”

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3.2 The water is clean

The general objective for water in Rotterdam can be summarised as “clear and plant-rich

water”. To achieve this, it is not necessary for the surface water to meet the standards for all parameters.

Even surface water that fails to meet various parameters, for example, can still meet the final objective (biologically healthy water) with active control measures. With the right combination of measures it is possible to achieve “clear and plant-rich water” in most Rotterdam waters. By pressing the right buttons (the right combination of measures), this objective is achievable in almost all Rotterdam waters. If we meet this objective, the water in Rotterdam will certainly meet the Framework Directive water requirements.

Broadly speaking, the objective for water in Rotterdam is therefore the same, namely “clear and plantrich”. But there are of course obvious differences between the various types of waters, such as canals and lakes. A clear, plant-rich lake will be structured differently and will have a different combination of fish and plants from a clear, plant-rich canal. In Map V-a, water in Rotterdam is divided into six different types, the so-called water quality models. The present water quality and the objective for each of these types are illustrated in a colour illustration. In a cross-section the illustration provides a picture of what each water type looks like now and could look like after the implementation of an integral plan of measures.

A key element in achieving the desired water quality is the design of the waterways, with particular emphasis on nature-friendly banks. But management and maintenance of the waters also play a crucial role.

Map V-a watertypes

Leafy trees along waterways accelerate the accumulation of dredgings. The frequency and intensity of waste removal (other than plant growth) is related to keeping the environment clean; after all, the waterway is the lowest place in the district. As processing the dredgings is relatively costly, it makes sense to remove leaves and submerged waste and refuse such as stones and supermarket trolleys during the winter months. The frequency of maintenance is determined not only by the ecological quality and the water quality, but also by water resource management concerns and the importance of leisure use (anglers and boating).

To achieve the desired objectives (the water quality models), the 6-s method has been developed. This method looks at each water type and analyses the current water quality to ascertain which combination of measures is most effective for achieving the desired objectives. This method is described in box 3.

Additional packages of measures will be set up and implemented in the municipal district water plans on the basis of this method.

Although the outlined water quality models are in principle achievable for many waters in Rotterdam, it will take time and resources to achieve them. It is also likely to be impossible to do so for a small proportion of the water. We have therefore decided to at least produce and implement an integral plan for a realistic number of waterways within the planning period of the Waterplan 2 Rotterdam.

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B o x III W a t e r q u a l i t y m o d e l l i n g T h e 6 - S m o d e l a s a st e p p i n g - st o n e f o r i m p r o v i n g w a t e r q u a l i t y a n d e c o l o g y The

quality of the water in Rotterdam is poor and the ecological quality of the water also leaves a lot to be desired. In

the next few years, the city’s water will have to be cleaner and improvements will have to be made to the standard of the ecological water, partly as a result of the European Water Framework Directive. The usual method here

would involve drawing up a system of objectives, followed by an extensive package of measures. In the water plan we have opted for a new approach that would identify the factors that affect water quality and ecology. By being aware of and describing these factors it is possible to show what the most effective course of action is, and how

it can be optimally tailored to the local situation, for improving the ecology and quality of the water. This is done using the so-called 6-S method.

The ecological quality of a body of water depends on many factors, which can be summarised in the 5-S model applied to flowing waters. This is based on the principle that the life forms (such as plants or fish) that occur in water are

determined by systemic conditions, substances, structures, and currents (the Dutch words for these factors all begin Images of water quality in canals, water ways and streams: current situation and future situation

with the letter ‘S’, hence the name). Systemic conditions (such as climate and geology) are more or less fixed, while substances (such as nutrients), structures (such as bank slopes or weirs) and currents (such as retention time and

seepage) in particular are often strongly influenced by man. By identifying all these factors it is possible to pinpoint ecological problem areas, while making clear the measures that are needed for tackling them. The Schieland and

Krimpenerwaard District Water Board has added a sixth factor to the 5-S model, namely that of cleaning (see figure 1).

System conditions Climate and geology

subs ta n c e s

- nutrients - toxic substances

structu r es - dimensions - banks, etc.

hydrology - flow - connections

sp e c i e s

fish, microfauna, plants, algae, etc.

cleaning

maintenance, dredging, mowing, etc.

Lakes (Kralingse Plas) open water (above) and bank (below): current situation and future situation

Figure 1. Relationships between the factors of the 6-S model

The application of this system involves the use of water quality modelling. Water quality modelling is a

reproduction of the ecological condition of a body of water on the basis of a sketch or drawing and the factors (the six ‘S’ factors) that determine this quality. Our aim for Rotterdam is that in due course all bodies of water should be ‘clear plant-rich water’. In order to achieve this, multiple measures will in general be needed to deal

with the various factors of the 6-S model. The water quality model gives an overview of the present and desired ecological situation, and the means by which the latter can be achieved.

Various water quality models are relevant to the five types of surface water in Rotterdam. Figures 2 and 3 each show detailed water quality modelling for two types of bodies of water, moats, canals, streams and lakes. The

water quality model shows the parameters of the 6 S’s for the present situation and an impression of the water as it is today. The parameters that do not meet the required standard in this current situation are coloured red. The future situation shows what the quality could ultimately be like if an integrated approach were to

be applied. The water quality modelling will have to be detailed further in sub-plans, including determining the parameters of the 6 S’s for individual water courses. This can then be used for drawing up an effective integrated package of measures. (Waterkwaliteitsbeelden Schieland, 2006)

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‘Discrepancies in ambition and awareness’ From as far back as the 16th century, Piet Kalkman’s ancestors have worked in the fishing industry in the province of Zuid-Holland. With that kind of background and a wealth of practical knowledge about water quality and water management, Kalkman is now – in 2007 – head of his own research and consultancy firm centred round the fishing industry. His advice is to “use the eyes of people who are really in the know more often.”

Kalkman can be found on the water on a daily basis. As well as carrying

out research into water quality, his company specialises in the removal of fish stocks in advance of any dredging work that is to be done. “There are no longer any real areas of nature in this country,” says Kalkman matter-

of-factly. “Residential areas have expanded too much and the demands on

nature have been stretched to the extent that all bodies of water have to be managed wisely, depending on their function and geographical location.”

He believes that when it comes to what you might call ‘water management’ with a rather fancy term, everything is interconnected: in other words, if

the quality of water deteriorates this will affect fish stocks, or if there are

changes to vegetation on the banks, that in turn will have consequences for life in and around the water and not least for the quality of the water itself.

“With the increase in levels of rainfall and the growing problems of flooding, it is important that the drainage capacity of ditches, waterways and lakes is maintained or, wherever possible, increased. It is also vital that fish have a healthy environment in which to live. Removing fish species that burrow in the sediment, like carp and bream, will help water become clearer and allow water plants to be able to flourish more easily, and this in turn will result in fish stocks becoming more varied.”

As an entrepreneur, Kalkman is pleased with the ambitions of the government to improve water quality (such as through the European Water Framework Directive) and the drainage capacity of both existing and future bodies of water, although he does have some comments: “I can still see clear

discrepancies in ambition and awareness between the various Water Boards.

I have also noticed that the information that we provide is not always

interpreted correctly, or is sometimes distorted somewhat for purposes of

convenience. That is a serious issue. If you want to set out sound policies, it

seems to me to be a matter of the highest priority that you do so on the basis of accurate information.” Kalkman is currently working on an assignment in

Barendrecht where, among other tasks he is carrying out, he is measuring the

present level of fish stocks and making an estimate of how they will develop in the next few years. “What I would like to see,” he says, “ is that we, the people who really know what we are talking about – nature’s own professional eyes, you could say – could get closer to those who take the final decisions.”

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3. 4 A properly functioning wastewater collec tion system is essential for the Water City

3.3 Water for an attrac tive city

This is perhaps the most important decision being taken in the context of this water plan. In order to

realise Rotterdam Water City, in view of the costs involved, it is clear that we will have to explore measures

that will enable us to cope with our basic water requirements in a sensible, innovative way. In view of the

basic urban requirements and related concerns, the central point of departure is that we use water to achieve

“Wastewater must be taken quickly and efficiently to a treatment plant; clean rainwater must be captured

an attractive, economically strong city. As was stated in the first paragraph of this chapter, Rotterdam is

on a large scale or its runoff into large areas of surface water delayed.”

The point of departure for ‘wastewater collection in the Water City’ can be summarised as:

protected. But we also want to have water ‘assets’ in the outside space. The question is: how can we give shape Important preconditions for realising this vision in terms of spatial planning, the design of our outside

to this?

space and the water in the city are: Rotterdam has many attractive aquatic environments. The Maas is an important inland navigation route, a mooring location for the SS Rotterdam, an event stage (e.g. the Red Bull Air Race, World Port Days) and the

- raising awareness among the general public that a good wastewater system benefits health, but that in times of extreme rainfall, flooding is inevitable (communication);

site of some special residential environments (Kop van Zuid, Hooge Heren). The canal areas are still much

- making structural arrangements for rainwater storage on private property;

sought-after residential environments, as are the residential areas at Kralingse Plas and Bergse Plassen.

- making structural arrangements for the visible runoff of rainwater on public property;

Rotterdam is already a city with many attractive places. In the Rotterdam City Vision it has been decided to

- allowing space for water and its storage on public property.

enhance the environments that are already strong, and in doing so improve the city’s attractiveness in stages (the expansion strategy). This also offers great opportunities for meeting our basic water requirements.

C r i t e r i a f o r s e pa r at i n g c l e a n a n d d i r t y w at e r The vision for the wastewater collection system

in Rotterdam cannot be seen in isolation from the vision for the way in which we deal with rainwater.

In the area outside the dykes, the most important existing quality is the river itself as a carrier of economic

Separating clean rainwater from the dirty wastewater stream is the starting point, and the basic

activities, a stage for activities and a setting for special residential environments. The present dynamic of

requirement is that this must not adversely affect the quality of our water or our groundwater, the quantity

the river is a special feature; the water level varies with the tide and with seasonal drainage of water from

of water and groundwater, or public health. Naturally, solutions for achieving this must be suitable,

the river. It is obvious that these qualities of the River City (the part of Rotterdam located on the Nieuwe

financially viable and practicable. Another important requirement is that the wastewater collection system

Maas) should be further enhanced with dynamic residential environments and, where possible, by extending

must be manageable and robust. It is not realistic to aim for systems that can completely separate dirty

transport by water.

water from clean water throughout the whole of Rotterdam.

In the north of the city this means improving the canal environment, enhancing the qualities of Kralingse

Different approaches will be used to separate clean water from dirty water depending on the type of urban area.

Plas and Berge Plassen and further developing good connections with the outside (making optimum use of the ‘boezem’ system). For the other areas in the north of the city, improving the (water) quality is an obvious

N e w bu i l d i n g s a n d r e s t r u c t u r i n g In general it can be said that where new buildings are built or

building block in the overall plan.

large-scale restructuring is undertaken, minimally improved, separate systems are being constructed. In addition, clean surfaces are not being connected to the wastewater collection system where possible. The

In the south of the city, the renovated Zuiderpark and its new water system is a real water ‘gem’. Not only is

rainwater from such places is drained visibly into the surface water. Any moderately polluted surfaces

the Zuiderpark an existing quality which permits existing and new districts to be upgraded and restructured,

discharge into the surface water via a soil or roadside drain.

but it is also the perfect ‘bud’ from which the water network and the water quality can be extended further.

In fact Rotterdam-Zuid offers more such opportunities: the De Twee Heuvels park in IJsselmonde can be

Draining rainwater into surface water through metal plate type filters is not yet considered to be

considered as a new ‘bud’, just like other new locations being developed.

manageable or robust. This will be only used tentatively in Rotterdam in the coming years unless nationwide surveys reveal otherwise.

But enhancing existing qualities is not enough. The problems outlined in Chapter 2 are of such a magnitude that not everything can be solved using existing methods. The traditional solutions will be inadequate:

In densely populated areas it is often not practical or feasible to convert the existing mixed wastewater

traditional building in the river will irrevocably cause problems. The basic water requirements in the existing

collection system on a large scale. The most important reasons for this are:

city (particularly in the city centre and the old districts) cannot be met by simply excavating extra water

- too little underground space available to build a properly functioning second rainwater system;

storage. The cost of doing so is exorbitant, quite apart from the fact that existing buildings cannot simply be

- too little surface water present into which to drain clean rainwater;

demolished to create extra water storage. And water storage requirements on business premises cannot always

- too great a risk of polluting the drained rainwater because of the intensive use of space;

be met with traditional means alone either. Alternative solutions and innovations will be needed if we are

- no effective possibility of clustering a sufficient number of sewer replacements: our compact city

to be able to meet our basic water and urban requirements properly. Innovations such as green roofs, water plazas, alternative forms of water storage (both above ground and underground) and the like are crucial for the

cannot be opened up everywhere for sewer work; - destruction of capital if sewers that are still functioning properly are replaced.

further development of the city.

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Where sewers are being replaced in densely populated areas, the existing mixed wastewater collection system

It is not only government bodies that are keen to capture and store water. The public, housebuilding

will be re-laid unless the construction of extra surface water areas presents an opportunity to deal with

associations and businesses will also have to hold or store water on their own premises. Rotterdam and the

rainwater in a different way. Other measures are needed to prevent flooding and improve the water quality.

water boards will increasingly facilitate this.

Capturing and delaying the runoff using alternative technologies such as green roofs and water plazas are therefore the preferred options in such areas.

3.5 Implementing together

Disconnection is only considered where there are clean surfaces located near the surface water. In such cases rainwater can be drained into the surface water without the need for a treatment facility. In such cases, the preferred option is surface runoff and therefore visible draining of rainwater. This minimises the risk of wrong

The core concepts in this paragraph are ‘implementing’ and ‘together’. Since the Waterplan

connections.

Rotterdam 2000-2005 was drawn up, collaboration between Rotterdam and the water boards has intensified. Where problems were previously tackled pragmatically and on an ad-hoc basis, we are now

G a r d e n c i t i e s In the more spacious districts there are plenty of opportunities for separating clean and

working from a common objective to improve the water system. But what got off to a cautious start in

polluted water flows. The aim in these areas is therefore to improve the separation systems. In doing so it will

Waterplan I, namely collaboration with spatial planners, has proven to be key for a successful approach to

be necessary to replace the sewers in clusters if possible. There is also a reasonable amount of surface water

our basic water requirements.

present in these areas, so there are more opportunities to disconnect clean surfaces.

D e a l i n g w i t h r a i n w at e r - a g e n e r a l o u t l i n e We need to change the way we think about water on our

C o a l i t i o n p r o j e c t s The water problem is not easy to solve; several different parties are needed to do so.

streets. The amount of rainwater running off along the surface of streets or public parks and gardens is set to

This is because despite the Rotterdam water system being a cohesive whole, it is managed by a number of

increase. The challenge is to turn flooding into ‘living with water’. Water must once again become a normal part

different parties. Some of the basic requirements are so simple and clear that the party responsible works

of our public spaces. Water in streets and squares (water plazas), water as part of public parks and gardens,

out and implements a solution for them. But the joint ambition for the water plan also means that in order

water in water storage facilities, on the street but also in the road drain, will become a normal part of the Water

to arrive at an actual solution, a number of different managers need to work together simultaneously.

City. Road and garden designers must therefore also lean to think ‘waterproof’.

The urgency of our basic water requirements makes it necessary for the various parties to sit down together to arrive at solutions, not only because flooding is occurring more and more frequently in Rotterdam’s cellars and streets, but primarily because there are many opportunities to make Rotterdam an even more attractive city. The basic water and urban requirements have a mutual influence on one another. This concerns so-called coalition projects. A significant basic water requirement can result in a programme with a water-rich residential environment, and the places where restructuring is taking place are ideal for making changes to the water system.

The interventions and strategies mentioned make it possible to tackle the water problem and at the same time enhance the quality of the city. Collaboration and coordination can result in better and more efficient solutions, and the financial aspect becomes more feasible if more parties are involved. As water not only costs money but also delivers an outcome (e.g. higher house prices), it is more attractive for organisations such as housing corporations to get involved. At the same time, such initiatives are also attractive for the province, the government and even the European Union, particularly when it comes to subsidies for successful integral urban development projects.

B us i n e ss a s usu a l Much work has been done in recent years on improving the water system in

Rotterdam. Water Plan I included an entire list of projects, some of which have been implemented and some that are still under way. We will continue to press ahead with the projects that are not yet completed.

Considerable efforts are being made to set up and update the municipal district water plans, implementing the municipal wastewater collection plan, management and maintenance, dredging and monitoring.

All in all, the above means that we must start actively collaborating with a large number of different parties and on various levels, from municipal district to national government and province, and from a local to a European level. The key issue is that we will be realising the projects together in practice. We therefore take a look at the conditions for their actual implementation in Chapter 5.

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‘We want to give water a human dimension’ As far as the Programme Secretary of the ‘Leven met water’ (living with water) foundation, Corné Nijburg, is concerned, the emphasis of the name is indisputably on the word ‘with’. “Particularly in a country like the Netherlands, you can only keep the water at bay to a certain degree, so it makes more sense to find out how best to respond creatively to the increased presence of water. Hence, living with water!”

In the same way that death and life are inseparable, so are flooding and water, especially in the Netherlands. The parallel between the two is that you can systematically reason away the unpleasant aspects of life, but this stands in the way of a sensible, well-considered and natural way approach to the problems rather than eliciting it. Nijburg says, “We

are not against raising the dykes or making further improvements to drainage systems,

but we do say this: don’t tell fairy tales and certainly do not forget that a slogan like ‘no

more flooding, ever’ comes at a price. Other options must therefore also be investigated.”

Many parties are active in the ‘Leven met water’ network: water boards, local authorities,

provincial governments, knowledge institutes, engineering firms, contractors and central government. The guiding principle is to put people first when dealing with present and future issues concerning the management and perception of water.

“We are involved in various projects, in which practical knowledge is being developed to give water a new status and a human dimension. In so doing we are attempting to conquer mistrust about water and to exploit opportunities. After all, the more you know about water and about how it is perceived by people, the less will be the shock and worry when it occasionally does reach beyond its normal boundaries.”

Apart from this process of raising awareness, the foundation is also involved in

initiating new working partnerships and processes in order to get innovative design plans off the ground. For example, knowledge is being developed in order to restore water to the historic town centre of Gouda and, where possible, to reinforce its

presence, all part of the ‘Hollandse Waterstad’ project in the town. Nijburg continues, “Through citizen participation, and by establishing links between the various layers

of the relevant administrative bodies, we are trying to create a town centre there that is attractive and safe for all parties, whether local or not. We aim to find a balance

between encouraging the economy and tourism, using cultural and historical assets, and creating a sustainable water system.”

Obviously in such a pioneering role like this you are faced with disappointments now and again. “Somehow or other it has not yet proved possible to set up truly groundbreaking experiments, such as a floating district that can cope with different levels

of water in a natural way,” explains Nijburg. Why is that? “It’s only logical. The word ‘experiment’ entails the possibility of failure, and that frightens some parties off.”

Nevertheless he is happy with a memorandum like the Water Plan 2 Rotterdam, in

which the opportunities associated with water and the vision on its added value for

different living environments are emphatically addressed. “Particularly in Rotterdam and for its inhabitants, water has so much to offer. There is still a world to win.”

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2 0 3 0 rot te r da m v i s i o n This chapter describes what Rotterdam might look like if the various basic water requirements are incorporated that contribute to Rotterdam’s main objectives. Or put another way: how can water resources be incorporated to help strengthen the economy and increase Rotterdam’s appeal as a city in which to live. For as described in the previous chapter, this is the key challenge for all.

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4 .1 Three Principal Areas, Three Strategies

The 2030 Rotterdam Waterstad Vision is based on strengthening existing qualities on the one

hand and on intelligently anticipating new trends on the other hand. The 2030 Rotterdam Waterstad Vision therefore is not an unattainable future vision, but instead makes use of ingredients and qualities that are already present in Rotterdam: some are visible, while others are latent. Building onto and expanding existing qualities is a strategy that is consistent with the ‘Olievlek’ [expansion] Principle’ used in the Rotterdam Urban Vision.

The 2030 Rotterdam Waterstad Vision in particular addresses the issue of how the basic water quantity and safety requirements can contribute to the city’s main goals. The basic water quality requirements, the basic wastewater collection requirements and the groundwater issue of course also impact the city’s appeal, but are not the main topics of this chapter.

We have divided the city into three main areas: The River City, North and South. The main water systems, as well as the urban conditions vary from each other to such an extent in these three areas, that the solution spaces and the strategies to be followed are different as well. This section provides an overview of this tripartite division. This tripartite division for all practical purposes is consistent with the tripartite division used in the City Vision, with one exception. The city centre which in the City Vision is part of the International City on the River is here considered part of the North area.

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Perspec tive Rotterdam Watercity 2030

GENERAL Residential areas New residential areas Contruction lines Industry and business areas Public gardens and forest RIVER CITY Existing outer dyke construction areas New outer dyke construction areas Dyke structure Dyke as urban balcony Dyke as urban balcony Outer dyke industrial areas NORT H Canals and waterways Water plazas Green roofs Water gardens (New) nature and recreational areas SOUTH Canals in Oud Zuid Water plazas in Oud Zuid Green roofs in Oud Zuid Water plazas in suburbs Water pearl Zuiderpark Open water connection Zuiderpark-Carnisselanden Temporary water retention basin H OEK VAN H OLLAN D Infiltration Watercentrum West Seepage water storage (New) nature and recreational areas

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Development beyond the dikes begs the question under what conditions this development should be allowed to take place, while taking the uncertainty concerning the rise of sea levels into account. Safety remains an uppermost concern, however the way safety is addressed is different from before.

The strategy for the River City proposes new conditions under which these areas can be developed and managed. Development in the areas beyond the dikes must anticipate the expected rise in sea and river levels. The most conservative assumptions are based on a relatively limited rise of a few decimetres for all of the 21 st century. But some forecasts are much higher due to the melting of the ice caps. The only certainty we have is that the water will rise, we just don’t know by how much. Interventions in areas beyond the dikes will therefore have to be designed in such a way that the possibility of further raising and/or strengthening the main dikes always remains intact. The density parameters for the areas beyond the dikes will have to be defined such that there remains sufficient space for implementing the adaptive strategy for the main dikes.

The strategy can be implemented by literally setting aside enough space for further dike elevation, but also by implementing new dynamic river living environments. At the same time a proper connection must be created between the existing city and the new river living environments in the areas beyond the dikes. This means that the barrier function of the dikes must be renounced, without thwarting the possibility of raising the dikes at some time in the future, but also without creating fallow laying no man’s lands between the old and new city.

GENERAL

Figure 12. International Rivercity (from: Stadsvisie Rotterdam)

Residential areas New residential areas Contruction lines

Rivierstad – The River City

Industry and business areas Public gardens and forest RIVER CITY

The River City roughly consists of the area situated beyond the dikes, including the main dikes.

The River City is characterised by Rotterdam’s symbolic identity: the Maas river. The city’s location along

Existing outer dyke construction areas

the Maas is Rotterdam’s unique quality. The Maas literally is Rotterdam’s lifeline. The river constitutes the

New outer dyke construction areas

link between the harbour – the economic engine – and the hinterland. The waterfront with the Kop van

Dyke structure

Zuid, the Lloyd Quarter and other developed areas is characteristic of Rotterdam. The river is Rotterdam’s

Dyke as urban balcony

inner city expansion area for a wide range of living and working environments. The Waalhaven and the Eemhaven harbour areas are stepping up the need for short-sea and harbour and knowledge-based services.

Map VI-a Perspective Rotterdam Rivercity 2030

Dyke as urban balcony

In the Vierhaven and the Merwehaven harbour areas to the north and in the Rijnhaven and Maashaven to

Outer dyke industrial areas

the south there is room for a total of 10,000 homes. These homes represent a significant portion of the goal to build 56,000 homes in the existing urban area before 2020.

No safety standards have as yet been established for the areas to be developed beyond the dikes. The Large Rivers policy directive assigns own risk and liability for any damage caused by high waters in the riverbed

The river also offers opportunities for further expanding water transport. This significantly reduces travel

(for areas beyond the dikes). Developers in the riverbed area are liable for damages and are responsible for

times and improves the accessibility of these areas. This type of transport furthermore allows Rotterdam

taking measures to protect themselves against potential damages. By selecting a method of construction

to differentiate itself and this also has an important recreational value. The river is the city’s largest

or by situating an activity so that the probability or the impact of high waters is as small as possible, the

recreational area. It is possible to create a recreational route along the entire length of the river, a chain

user can significantly limit risk in terms of safety. Eligibility for insurance against damages will depend on

of special sites where the river, the city and the harbour can be experienced in a different way each time.

this. The dynamics resulting from water-adapted building designs, floating or on piles, offers interesting

Broadly speaking, this is the future vision as it is stated in the Rotterdam Urban Vision.

possibilities in this respect.

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Nor th

The north shore consists of a large number of different sought-after living and other environments.

This is where the largest portion of the city’s centre is located. Successful office locations, such as the Brainparken and Alexander, as well as much-loved living environments, such as Kralingen, Blijdorp and Hillegersberg. The water is a major contributing factor here: living along the Kralingse Plas, the Bergse Plassen and along the canals up North is very much cherished.

GENERAL Residential areas New residential areas Contruction lines Industry and business areas Public gardens and forest NORT H Canals and waterways Water plazas Green roofs Water gardens (New) nature

and recreational areas

Map VI-b Perspective Rotterdam North 2030

The North strategy consists of focusing on holding and delaying the rainwater as much as possible. In areas where space is at a premium, such as in the inner city and the old city districts, innovative solutions Figure 14. Using the qualities of Rotterdam North (from: Stadsvisie Rotterdam)

are being applied. In areas where quality drainage waterways and canal systems already exist, the focus is on strengthening and expanding these facilities wherever possible. An example of this is the Groot

The requirement for the north shore is focused on further expanding these existing qualities. The starting

Kralingen region. Important qualities of the Groot Kralingen of course include the Kralingse Bos woods

point in this regard is the strength that this region already possesses.

and the peaceful urban living environment in Kralingen. In areas where new development (such as on the city’s nursery or the auction hall site) or restructuring (such as in Jaffa, sections of Crooswijk and

The North’s water system is characterised by a system of drainage waterways and canals. Any overflow is

Oud-Mathenesse) is planned to take place, the expansion of the canal system is a logical choice. The

drained into the Nieuwe Maas river. A large portion of the water storage facilities are however provided by

restructuring of commercial properties also provides an opportunity to strengthen the water system.

the wastewater collection system. Due to the high percentage of hardened surfaces, the water system in the

North is after all characterised by a large number of locations for expansion, such as Nesselande, Park

North segment has a high water storage requirement over the short term: the current situation calls for an

Zestienhoven and Schieveen. All of these areas have as a basic requirement (insofar as this has not as yet

additional 193,000 m of additional water storage.

been settled) to include water as an important quality banner for the plan.

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South

The Zuiderpark with its new water system, the existing canals in the Old Zuid city district and the

The opportunities in Rotterdam South are exceptional, but the issues are not exactly commonplace.

waterways in the southern city gardens form a network of public spaces that could form the basis for a more

This therefore requires an extraordinary approach. Investments in the South are significant and forces are

extensive water living network. By interconnecting new canals, waterways and water living environments

being bundled into the so-called Pact op Zuid, the South Pact. The South Pact is founded on four pillars: to

to the Zuiderpark’s ‘water pearl’ an integrated water network is created over time. This way water literally

magnify the social, economic, physical and cultural qualities of the South.

becomes a connecting element between the Zuiderpark and the improved or new living environments.

This dynamic water network delivers a major contribution to the restructuring of the South in two specific ways. First, it forms an important basis for the realisation of completely new and differentiated water-rich living environments, particularly in the Southern Garden Cities. Secondly, it provides the possibility and the pretext for creating a new link between this water network and the nature reserve and recreational area situated between Rhoon and Portugaal. This link is essential from a water management perspective in order to channel water from the Midden-IJsselmonde to Rotterdam during periods of drought. At the same time it creates an attractive shipping and recreational link between Rotterdam South and the MiddenIJsselmonde, including the latter’s landscape qualities.

In addition, a similar strategy to that used for the old city districts in the North area, will be applied to the Oud-Zuid city district, which primarily consists of dense, pre-war neighbourhoods: a plethora of innovative solutions such as water plazas, water roofs, water channelled below buildings, etc., combined with newly to be excavated canals.

Map VI-c Perspective Rotterdam South 2030

Figure 15. Opportunities for Rotterdam South, (from: Stadsvisie Rotterdam)

GENERAL Residential areas New residential areas

Water could play a major role in the realisation of these objectives. Aside from the Kreekse Boezem, the water system in the South does not incorporate any drainage systems. The current water system provides

Contruction lines

opportunities for implementing an integrated system of waterways. Leveraging water resources as an

Industry and business areas

opportunity, however, requires fundamental interventions in the urban region.

Public gardens and forest SOUTH

The Zuiderpark (adjacent to the Kop van Zuid) is the South’s strength and represents the base from which

Canals in Oud Zuid

the South could be further developed. The restructuring of the Zuiderpark also yields major opportunities

Water plazas in Oud Zuid

for the water system. Flexible water level management, purification and the construction of nature-friendly

Green roofs in Oud Zuid

shores not only will result in the creation of additional water areas; it also creates outstanding water quality. An obvious approach therefore is to use the ‘water pearl’ of the Zuiderpark as the core base from

Water plazas in suburbs

which to develop the water network for the South.

Water pearl Zuiderpark Open water connection Zuiderpark-Carnisselanden Temporary water retention basin

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‘The total picture as source of inspiration’ Water as a problem? Or water as an opportunity? That is the dilemma facing Pact van Zuid programme manager Karin Schrederhof. “The sudden change towards positive thinking and seizing opportunities is something I find exciting and I want to provide as much encouragement as possible. However, it does require a vision for the future and a joint strategy. Water Plan 2 Rotterdam is a piece of that puzzle.”

It is a cast-iron rule that when things are going well, there is little willingness

to change - ‘never change a winning team’. But like other cities, Rotterdam-Zuid is facing increasing problems of flooding. Schrederhof says, “As a government you can set out your boundaries and simply say, ‘this bit is your problem and

this bit is ours’. But it is far more effective to look at how your solution might make a positive contribution to the problems of the other players, and vice

versa: how their solution could help solve or mitigate your problems.” Against

that background, Schrederhof has always taken an active approach in both her

current position at Pact van Zuid and her previous position as operations director at Vestia. “There is no point in waiting around for each other. Especially with the present climate problems, that is a complete waste of time.”

Because she feels so passionately about creating quality and attractive

living environments for the various districts and their residents, she is very

enthusiastic about the opportunities for new investments that are offered by Water Plan 2 Rotterdam.

“A lot of work and renovations are of course already being carried out when it comes to homes, but a new lake or other body of water could create a whole new kind of zest. It means opportunities for people to meet, for leisure, for social contact.”

As lakes and other bodies of water are a considerable burden on the budget, and given the imminent discussion about who pays what, Schrederhof is in favour of close cooperation between government, corporations and developers. “However, if there is a clear vision about where Rotterdam wants to go as far as water

management is concerned, and if that shows that everyone will gain in the long run, I am very optimistic. In a way, Water Plan 2 Rotterdam is an ideal steppingstone for that new zest.”

Schrederhof is already looking at the government coalition agreement and

can detect, on top of all the present opportunities, new openings that could

provide a further impulse for public spaces. “If I understand the signs correctly, the willingness to invest in the areas in Zuid is considerable. Water could play

an important role here. It is the task of Pact van Zuid to convince the national

government of the need to consider the whole picture, in other words not only

to improve homes, education, and healthcare, but also to ensure an environment that is more attractive, more varied and more human-friendly. To a significant extent, Water Plan 2 Rotterdam could be that beckoning total picture.”

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B o x IV - WATER PLA Z A S Th e B a s i c R e q u i r e m e n t Rotterdam traditionally drains its rainwater via an extensive underground sewer

C o n c e p t u a l S o l u t i o n s Water plazas therefore help

system. The city consequently has few water surface areas that are able to retain water. It is evident that

solve the basic water requirements. But there are other

nothing is done, similar problems will crop up in other areas as well. Increased rainfalls are expected over the

• Water plazas make the basic water requirements and

the wastewater collection system is currently encountering problems in handling rainwater in some areas. If

coming decades and rainfalls are becoming increasingly severe. In particular severe rainstorms of short duration cause problems in densely populated urban areas: there are too many hardened areas and build-ups, as a result

of which the water has nowhere to go. Damage and flooding is the result. This includes things like large puddles on streets, or flooded cellars and basements of homes and hotels. Frequent flooding adversely affects the city’s image. Things must therefore be done differently. This is why Rotterdam is introducing a new type of water storage: the water plaza.

benefits as well:

solutions visible and tangible as part of the day-to-day cityscape. The water elements within the city have an

educational objective (“Living with Water”): water is fun, interesting, useful or usable.

• Water plazas contribute to the development of

sustainable water management systems without the

need for tackling the entire system all at once. In other words, a step-by-step, small-scale approach is feasible.

• Financial benefits result from developing a single area as a public space and for collecting water at the same time.

H i n d r a n c e A water plaza is not a plaza in the classical sense of the word, but a collection basin. This basin

collects and retains rainwater. From here it can slowly be absorbed into the groundwater or be drained to a

sewer or to surface water at a later time. The water plaza is dry for most of the year and during that time can be used just like any other public space within the city. Following a heavy rainfall it is used for storing water.

This way water plazas not only solve the immediate problem of collecting rainwater generated during peak

rainfalls, but they also provide a unique opportunity to implement special types of public spaces, where the quality of staying in the plaza is linked to the collected water: places that become enjoyable when it rains.

The ability to apply the water plaza concept is based on

anticipating the city’s existing water management facilities

and the existing wastewater collection system in particular.

The water plaza supplements the existing system. Three

The problematical areas in Rotterdam

conceptual solutions have been identified as follows.

1 . Th e E n c l o s e d B a s i n In this case the water plaza is

directly connected to the wastewater collection system. An additional storage capacity is created using an overflow or a pump. As soon as the wastewater collection system

has sufficient capacity after a heavy downpour, the water collected is pumped back into the wastewater collection system. Suitable locations for this are located in the

immediate vicinity of the main wastewater collection

system. This type of water plaza cannot be developed as

an open plaza, because the water is dirty. This is why the basin must be covered. There are several possibilities for

transforming the water into water for public enjoyment.

W at e r P l a z a P r i n c i p l e Water plazas are not new. It was a common practice in old cloisters to collect

rainwater from roofs and hardened surfaces in a central area. This was not only practical, but also had a

spiritual significance. In fact, even today all kinds of water plazas exist. For example, a flooded underground

parking garage or the area of a street leading up to a speed ramp. These areas also temporarily trap rainwater.

Except these spaces are currently not designed to store water and are often located in the wrong place. We

want to develop a classification of potential water plazas for Rotterdam, based on their innovative and spatial

characteristics. The intent is not only to create a sustainable water management approach for the city but at the same time to improve the quality of the living environment and public spaces. There will be a special focus on 19th century districts and the city’s centre, which is where the largest basic water requirements exist.

The floor of the water plaza can be connected to the water

level in a different way. It is also possible to design the floor of the water plaza in such a way that it is possible to make use of the space above it. In that case the underground

water is not literally available for public enjoyment, but the construct is such that it is possible to create a new public space on top of the water plaza. The depth required to

create a basin can be used to provide this public space with additional relief and at the same time make it suitable for

aboveground rainwater collection as well. In this case there is an enclosed, as well as an open basin.

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Ex a mp l e s The three conceptual solutions can be easily

combined to produce six sample water plaza types: the

smart streetscape, the submerged plaza, the dam, the deep plaza, the shallow plaza and the water balloon.

1 . Th e S m a r t S t r e e t s c a p e The most local solution is 2 . Th e Op e n B a s i n This water plaza receives

its water directly from the open spaces and

possibly from the roofs of buildings as well. The

clean water is collected and trapped and thereby relieves the wastewater collection system, even

during regular rainfall. After temporary storage,

By making simple modifications to the profile of the

streetscape it is possible to collect water. This can be

accomplished by designing the roadway as a temporary water basin. Parking spaces can also be used as a water basin.

the collected rainwater can be drained via the

For example, water can be collected on the roadway between

essential. If the water is of sufficient quality, the

be allowed to filter down to the substratum via openings or

wastewater collection system, but this is not

water – potentially filtered – can filter down into

the groundwater or evaporate. In view of the fact

that the open basin is a collecting area for caught water, the rainwater must be transported there from the surrounding areas. The best possible

speed ramps and raised sidewalk curbs. The water can then

partial openings in the hardened surfaces and the sand layer requirements, but is furthermore combined with increased traffic safety.

In case of a parking space basin, the parking spaces are

most suitable locations for concentrating water

water storage space. The strip for stepping out of the car is

collection. If the height differentials are too small, it is also possible to transport the water to the water plaza using a system of open or closed

gutters. This type of system is more often referred to as an open work, however.

3 . Th e Op e n N e t w o r k This water plaza

serves as a collecting point for local rainwater.

The water transport distances are minimised

and local rainwater is collected to the maximum

extent possible. In terms of draining the water, an obvious approach is to allow the water – possibly after filtering – to gradually filter down into the groundwater. This solution is particularly suited for locations where there are no significant

height differentials. The water plaza will consist of a network of small shallow plazas, styled

water ponds and new streetscapes. Immediate

application is possible in areas where currently there is regular water excess.

Three basic principles, six samples

below. This approach contributes to solving the basic water

approach for this is to use the city’s existing

height differentials. The lowest areas include the Fit locations for the ooen basin

found at the street level, within the existing streetscape.

constructed using an exaggerated slope, which creates a

located at normal roadway level or consists of the sidewalk.

The original drains serve as emergency overflows. The water can filter down into the ground via a sand layer. This solution can be applied to any street type.

Sample of the Smart Streetscape

2 . Th e S ubm e r g e d P l a z a Any plaza can be designed

for water storage. Portions of a plaza (or probably the

entire plaza) can be excavated by 50 to 70 cm (at a slope).

The deepened spaces are supplied with rainwater using a

separate system of gutters within a radius of approximately 150 metres. Depending on the size of the plaza, the

rainwater from the entire public space and potentially

from the disconnected roofs of the surrounding buildings

as well can be collected. The water will remain in place for a maximum of 48 hours and after this, and in the interim, is drained in a step-wise fashion into the wastewater

collection system and the groundwater. Depending on the

wind and temperature, a portion may evaporate (maximum 20%). It is possible to play in these shallow plaza spaces,

even when there is water. Because they are all situated at

depth, the design of the edges is important. These must be

durable and suitable for sitting. This water plaza is the most

convincing as a series of water plazas. The plazas are given a

distinct recognisable element and project the identity of the unified whole. This identity is strengthened when it rains because the plazas will flood at the same time.

Locations that require a form of open network Series of submerged plazas in Rotterdam West 100

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5 . Th e S h a l l o w P l a z a This solution is the cheaper

and less voluminous family member of the enclosed

basins. This involves a shallow underground reservoir

that is directly connected to the wastewater collection

system via an overflow, with a plaza on top. Because the

cellar remains above groundwater level, it is significantly 3 . Th e D a m ( at t h e f o o t o f a s l o p e ) This type of solution takes

advantage of existing height differentials. The principle is simple. A

damming wall to hold back the water is built at the bottom of a slope. The concept can be extended by continuing the slope deep into the ground in Strategic insertions of dams in Rotterdam North

adjacent flat areas, as result of which the damming wall will be located

below ground level. The storage area is limited and usually there will be a series of “damming plazas” fed by rainwater supplied via the surrounding height differentials. Depending on the height differentials at ground

level, the height of the walls can differ accordingly. The wall serves a dual

purpose: from an extended open-air bar to an extended sitting bench and all variants in between. After rainfall, the water can flow back into the

cheaper to construct and it is therefore also possible to

construct more of them. The volume of rainwater that can be stored is still sizeable (up to a maximum of 5,000 m3).

The roof of the cellar construct is used to create a special public space in this case as well. Due to the fact that the cellar remains above groundwater level, the plaza will

be shallow as well. It will be possible to play in the plaza when it is dry. When it floods, a new waterscape could

emerge. Plazas of this type also involve aboveground as well as underground water collection.

6 . Th e W at e r B a l l o o n A good and simple solution

wastewater collection system, or in some cases be transported to a canal.

is to link an aboveground water bag to the wastewater

4 . Th e D e e p P l a z a The most voluminous solution is the deep plaza.

a delay during peak rainfalls and can accommodate large

This involves an underground reservoir that is directly connected to the

wastewater collection system via an overflow and with a plaza on top. This is an expensive solution, because the reservoir must be constructed with watertight walls and floors (an enclosed cellar). This is offset by the fact

that it is possible to store large quantities of water (approximately 10,000

m3) very rapidly. A public space can be created on the roof of this reservoir,

such as an amphitheatre that could also serve as an aboveground basin for collecting rainwater.

Optional layout for the shallow plaza

collection system via a pump. This results in somewhat of quantities of water (more than 5,000 m3). The water

balloon is constructed in the form of an “aquadam”. This is an existing design that can be adapted for urban use.

This could involve the addition of a protective layer above the inflatable component as a deterrent to vandalism.

The advantage of a water bag is that it can also be filled with air. When it is dry, it can be used as an object for

play and a jumping cushion. The water management sites that are suitable for such an installation are located near the main wastewater collection systems. The suitable urban areas are poorly used areas, such as the loadbearing spaces for large infrastructures.

A c k n o w l e d g e m e n t The content of this box was

made possible by the Water Plazas Study carried out

by the VHP and Urban Affairs with the support of the

Stimuleringsfonds voor Architectuur [The Architecture Development Fund].

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The Waterbaloon connected to the main drainage network

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Box V - Green roofs ‘Is it not against all logic when the upper surface of a whole town remains unused and reserved exclusively for a dialogue between the tiles and the stars?’ Le Corbusier There is a huge potential of roof space available within the Rotterdam Ring Road which, together with that of the Hordijk, Spaanse Polder and Noord West industrial estates, could be used for the construction of extensive sedum roofs. The surface area in question covers no less than 4,623,000 m2!

Benefits

• Green roofs reduce the burden on public sewerage systems as the plants on the roofs absorb rainwater,

returning it via evaporation to the air. As a result, the release of rainwater in the sewerage system is reduced and slowed down and the quality of the water is improved.

• Green roofs lead to a better microclimate.

• Green roofs lead to better air quality.

• Green roofs protect the underlying material, as a result of which green roofs last much longer than

conventional roofs (green roofs are less susceptible to ageing as a result of the ultraviolet rays of the sun).

• Green roofs have a cooling effect in the summer and form a layer of insulation in the winter.

• Green roofs serve to replace other areas of greenery that have been lost to urban development, and therefore contribute to biodiversity and the quality of the living environment.

• Green roofs are more visually attractive that traditional ones.

• Green roofs reduce noise pollution.

H o w a r e t h e y e n c o u r a g e d ? Because of these benefits, many cities all over the world have launched

incentive schemes to promote the construction of green roofs. Many of these schemes have common features, including:

• Creating support and precedents: Many cities start pilot projects on the roofs of local authority buildings and Gebouwen mogelijk geschikt voor het aanbrengen van een extensief groen dak verdeeld per eigenaar

gather their own data (quantity of water storage, reduction in levels of fine particles, decrease in temperature, noise reduction, etc.) from these roofs. Many of the roofs are accessible to the public and are often used for

information and communication purposes. The schemes emphasise the ‘together’ aspect – both house owners and the government benefit from the construction of green roofs.

• Communication and information by the government: Almost every city with a scheme offers support in the form of advisors, information via meetings, brochures, websites, etc. This often includes the minimum guidelines for green roofs.

• Subsidy schemes: financial support from governments worldwide for the construction of green roofs varies

from 10 euros to 30 euros per square metre. In Germany it is particularly encouraged by means of a reduction in water taxes.

• Legislation: as a result of amendments to building decrees, green roofs will become compulsory for buildings with flat roofs that are either new or being renovated.

W h at d o e s i t p r o du c e ? In every city where green roof schemes have been successfully implemented, this

support – both financial and practical – has proved very important. A ‘green-roof scheme’ whereby a large number of roof hectares would be converted in a few years would bring benefits to various parties in Rotterdam: • Water Boards: reduced peaks, faster drainage, improved water quality;

• Local authority: lower burden on combined sewerage systems, improved water quality; • Local authority: fewer problems associated with fine particles, less CO2; • Local authority: improved levels of biodiversity;

• Local authority: greenest city in the Netherlands; • Local authority: improved urban climate;

• Homeowners and consumers: reduction in energy charges;

• Homeowners and consumers: better value for money, better quality of life.

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B OX VI - P u t t i n g t h e R i v e r R o t t e back on the Rotterda m m ap The River Rotte from which Rotterdam derives its name has more or less completely slipped from the public consciousness.

It flows along, tucked away among the quaysides and behind shops and bars. Ever noticed the Rotte when walking along Hoogstraat? Don’t forget that the river still largely follows its original course, running to the area outside Rotterdam.

Giving the Rotte back to the city means having clean water and a bustling river for the inhabitants of the districts that line the river, and for the city itself.

Combining work on water with improving the living environment of the city could provide that added value. This work should not only concern water

catchment and purification, but should also involve sailing and recreation, and the construction of restaurants and homes by the water.

With the help of a grant from the Ministry of Housing, Spatial Planning and the Environment, a large number of imaginative ideas have been drafted in an

evocative way. How about a city rice field or steps by the water, where you could sit and enjoy a bite to eat or a glass of wine, while the water slips gently by? Or perhaps you would prefer to sit among the bulrushes, or go to an outdoor

sports centre in the heart of Rotterdam from where you can rent a canoe and

sail towards the Rotte lakes. You could also go on a pub crawl along the Rotte,

stopping off at a Mediterranean or fish restaurant that uses fish freshly caught from the river. And if you want to stay the night, just book a place in one of the quayside caravans.

There are ideas aplenty! Now it is time to debate them, before turning them into concrete and socially affordable plans. In 2007 we are launching four potential projects. We will be presenting the ideas to all the relevant

organisations and commit ourselves strategically to the ideas that inspire all

and that generate the necessary funding. We are also looking at other ways of creating even more income from water. There is no reason why water should not create added value for the quality of life in the city and indeed for its

economy – there are enough entrepreneurs who would like to do business

there, and plenty of ‘Rotterdammers’ who would like to dine, live, work or just spend leisure time there.

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4 .2 Conceptual Solutions by City Distric t Type

At a lower level, it is possible to make a distinction between a number of different city district

types and the associated solution types. Within the tripartite subdivision of Rotterdam, as described above, the conceptual solutions for, for example, garden cities or industrial parks in the North do not by definition differ greatly from those for the South. For each type of region, only a few solutions for approaching the water requirements are usually feasible. We make a distinction between the following: the old city districts, the garden cities, the industrial parks, development areas and areas situated beyond the dikes.

The main water system, the type of area or city district and the translation of the water requirements result in a conceptual solution for each area. This section describes the conceptual solution for each area together with a map outlining the proposed interventions. The conceptual solution for each area must be further worked out in the form of sub-plans during a later phase.

C i t y d i st r i c t t y p e s Centre

Water storage requirement

Map VII - Types of measures within the dyke region

No storage requirement Old city districts

Municipality border M e a su r e s

Garden cities

Open water expansion Industrial parks Realization green roofs Oil stain strategy Realization water plazas

Development area

Additional innovative solutions

Outer dyke area

Th e C i t y C e n t r e : a g r e at d e a l o f d e v e l o pm e n t, v e r y l i t t l e spa c e f o r w at e r Conceptually, the

inner city is part of the city on the river, but only partially so from a technical water system perspective: the largest segment of the centre, one of the most densely built up areas of Rotterdam and one of the most important areas

Water piggy bank

for densification, lies within the dikes. The inner city is one of the areas that already faces major water issues. The current water requirement is 38,000 m3. The centre is transforming itself into a mixed working, living, shopping and entertainment environment. To correct the current imbalance between living and working, the inner city will have to undergo significant densification. There is space within the inner city to meet the demand for city-centre living. The target calls for the addition of 10,000 homes by 2030. The first step in enhancing the appeal of the inner city is to significantly improve the quality of the open spaces. Solving the water issues supports this objective. Highquality innovative solutions are being proposed for the city centre. The underground water storage facility below the Museum Park is a precursor of this approach.

Rotterdam is focused on transforming its open spaces in combination with solving its basic water issues. Squares, streets, as well as courtyards qualify as potential candidates. The city centre includes a wide range of different types of squares. In particular squares located in the proximity of a main wastewater collection system or an area where there is water excess are attractive candidates for transformation into water plazas. This includes squares in the Oude Westen or ‘t Landje city districts. Another possibility is to transform the large inner spaces into water courtyards. The area between the Goudse Singel and the Burgemeester van Walsumweg offer extensive possibilities in this regard, for example.

Finally, Rotterdam wants to encourage homeowners to accept their own responsibility and make a contribution to the realisation of increased numbers of green roofs. Green roofs are not only beneficial in terms of solving water issues, but in addition offer a wide range of other benefits as well (see Green Roofs box). The solution of various water issues in the city centre is therefore addressed by implementing all possible innovative solutions: deep water plazas, shallow water plazas, curved channels, water courtyards, green roofs, water below buildings. Combined with a very limited number of traditional solutions (such as locally increasing pumping capacity or water drainage), it becomes possible to use the major water issues as a means of making Rotterdam’s inner city more attractive.

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O l d C i t y D i s t r i c t s : l a b o r at o r i e s f o r i n n o v at i v e s o l u t i o n s One thing that Rotterdam’s pre-

between 1946 and 1967. The structure was determined on the basis of ideals about democratic community

war districts have in common is that they are fairly densely built up, incorporate large areas of hardened

living. Today, fifty years later, these districts are the objects of drastic renewal. This renewal is essential in

surfaces and consequently are sensitive to water excess. There is little room for providing additional water

order to enhance Rotterdam’s appeal as a residential city. The restructuring of the garden cities is primarily

surface areas.

focused on retaining residents. Residents who are moving up the social ladder are the most important target group in relation to the development of new homes. Another important element is to strengthen the

A number of districts are being developed around the heart of the inner city: Cool, Oude Westen,

differentiation between the various districts. Available living accommodations must be differentiated.

Delfshaven, Lloyd Quarter and Oude Noorden. Their central location, historic character and functional mix of living, hotel and catering services, stores and artistic institutions make these districts increasingly

In terms of the basic water requirements, it is important to note that the garden cities are characterised by

attractive to students, ex-students and workers in the creative economy – exactly the groups that Rotterdam

a relatively high proportion of green that is relatively poorly used. The Multiyear Investment Programme

would like to attract. From a social, cultural and economic perspective, these districts possess the required

includes an objective to reduce the proportion of green in open spaces by 20%. The solution to the basic

characteristics to autonomously initiate a process of gentrification that allows them to transform into

water requirements offers a major opportunity to dovetail with this objective. By focusing to the maximum

quiet urban living environments over time. Similar to the inner city, the basic water criteria for 2050

possible extent on creating new water surface areas in the southern garden cities, new conditions can

are relatively high and the initial focus here too is on innovative solutions in order to be able to meet

be created for developing attractive new residential communities and it becomes possible to convey new

basic water requirements. Where possible, such as in locations that are subject to small-scale and other

meaning to public spaces. The concept of an intricate water network, inspired by the public spaces in each

restructuring initiatives, new water surface areas can be added.

garden city, is the conceptual solution for the garden cities.

In Oude Zuid (the collective name for the pre-war Feijenoord and Charlois districts) there is a precarious

I n dus t r i a l pa r k s : a m i x o f c o s t e f f i c i e n t s o l u t i o n s Rotterdam has a large number of industrial

balance between the onset of gentrification and imminent decline. The pre-war districts are located between

parks, such as the Spaanse Polder, Noord-West and Hordijkerveld. A number of new industrial parks are

the Kop van Zuid and the Zuiderpark expansion areas, two opportunities for the South in terms of the

already being planned for the future, for specific business activities: airport-related activities at the Airpark

possibility of creating an attractive residential city. The approach used in these areas is highly dependent

of Rotterdam Airport and high-quality, knowledge-intensive activities in Schieveen.

on the distribution of ownership. Large areas that are owned by corporations (such as Hillesluis, Bloemhof and Vreewijk) will be the focus of restructuring initiatives. Districts that are predominantly privately

What is striking is that in particular the existing industrial parks already experience high water quantity

owned (such as Tarwewijk, Oud Charlois and Carnisse) are more difficult to coordinate. These districts do

as well as quality issues: the number of water surface areas is low as a result of which water levels can rise

require investment, however, in order to bring them up to par and to avoid the requirement for much higher

to unacceptable heights during downpours. The drainage of surface water is partially provided for by the

investment in the future.

mixed wastewater collection system. This is an undesirable situation from a sustainability and water quality perspective. The water quality in the various regions is often poor due to the presence of overflows, illegal

There is a major water quantity, as well as a water quality problem in Oud Zuid. Furthermore, there is little

discharge, runoff from roadways and lack of through-flow.

space for additional water surface areas. The strategy for Oud Zuid calls for the realisation of deep-water plazas at a number of sites where squares or street intersections are located along the main wastewater

What is clear is that the space and resources available in existing industrial parks will have to be dealt with

collection system. Due to their enclosed nature, these deep-water plazas could make a significant

in the most creative and efficient way possible. The focus on the sustainable use of space will have to be

contribution to solving the water quantity issue. In addition, this would allow the number of overflows in

maximised. The various basic water requirements can only be solved on the basis of a very carefully put

existing canals in the North area to be reduced, so that they also contribute to the water quality criteria.

together set of measures:

In the districts themselves (such as Bloemhof, Riederbuurt, etc.), the focus is on an intricate and robust

- Increase the interrelationships within the system and its self-purification capacity;

network of shallow water plazas and water drainage. The use of green roofs will also be strongly promoted in

- Add water surface areas where possible;

Oud Zuid. Only in a few locations, depending on whether large-scale restructuring initiatives will in fact be

- Add water surface areas at sites involving the re-profiling of streetscapes and the restructuring of

implemented is it possible to add water surface areas in the form of canals.

industrial parks; - Innovative solutions, such as water storage in road drains;

G r o o t K r a l i n g e n a n d G r o o t H i l l e g e r sb e r g : e xpa n s i o n - b a s e d a pp r o a c h Groot Kralingen

- Promote the use of green roofs; and

and Groot Hillegersberg both are valued residential communities located in the immediate proximity of

- Renovation of technical water infrastructure (culverts, pumping stations, overflows).

the Kralingse Plas and the Bergse Plassen, respectively. Both areas at the same time derive their identity from the canals and waterways. This existing canal and waterway structure can be expanded as part of the

New industrial parks are described under Development Areas in the next section.

“olievlekbenadering” [expansion-based approach] introduced as part of the Rotterdam City Vision. Where restructuring opportunities exist (potential areas identified include parts of Schiebroek, the region to the

A r e a s f o r D e v e l o pm e n t : i n c l ud e w at e r a s i n t e g r a l c o mp o n e n t i n p l a n d e v e l o pm e n t

south of Nieuw-Crooswijk, and Jaffa in Kralingen, or potential new locations, such as the city’s nursery and

There are sites in Rotterdam where new development locations or new nature preserves and/or recreational

the auction hall site to the east of the Kralingse Bos), new canals would form important symbolic identities.

areas are being developed in addition to existing developments. These are referred to in this document

Innovative measures only need to be applied in these areas at the local level.

as development areas. Over the past few years, Rotterdam has established a number of highly successful development areas in which water played a dominant role during plan development.

G a r d e n C i t i e s : l i g h t, a i r , spa c e … a n d w at e r Immediately after the war, new districts were built

in rapid succession at the edge of the city: the garden cities. The garden cities Pendrecht, Zuidwijk,

Nesselande is a very good example in which all facets of the basic water requirements were meticulously

Lombardijen, IJsselmonde, Hoogvliet, Overschie, Schiebroek, Ommoord and ’t Lage Land were built

included in plan development at an early stage. This has resulted in a successful district with highly

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NE W U R B AN A R EAS Floating residential

satisfied residents. In recent plans, such as Park Zestienhoven and Polder Schieveen, water also plays an

Terp residential

important role. In Park Zestienhoven, as well as Polder Schieveen, water requirements, combined with

Pier residential Public water

nature development were directly incorporated into plan development, whereby parties such as the Water

transport

District Board and Natural Monuments where closely involved.

NE W PO R T A R EAS

E X ISTIN G U R B AN A R EAS

Waterside stairs

integral elevation

Flood barriers

Communication

Water proof floors

Working terps

Detection system

Insurances

Flood barrier

Business castles

Regulation

Sandbags

Floating parcels

Storm barrier regime

Flexible flood prevention

Escape route

Flood bridges

The strategy for new development areas is based on these successful examples. Areas such as the Zuidplaspolder, Oranjebuitenpolder, Korte and Lange Bonnen come to mind: water is an integral component of plan development in all of these instances.

A r e a s b e y o n d t h e D i k e s : p r o t e c t e d , d y n a m i c a n d f l e x i b l e l i v i n g e n v i r o n m e n t s An

important portion of Rotterdam is situated beyond the dikes. It is precisely these areas that give Rotterdam its distinct character. A significant portion of the city centre, the Kop van Zuid, Lloyd Quarter and the city’s most important economic engine are situated beyond the dikes. The city’s new development areas (the old harbour areas that are to be transformed) lie beyond the dikes.

Rising sea levels and the increased probability of river floods are increasingly becoming a problem for Rotterdam’s areas beyond the dikes, and consequently for the city as a whole. The seriousness of a specific threat today is calculated using the formula: risk = probability x impact. By expressing risk this way, it becomes clear that the development of a strategy for the harbour region beyond the dikes is in fact of national importance.

Map VIII Types of measures in outer dyke area

A number of cities (London, Hamburg, Dordrecht) have gained experience in this area. For example, N e w U r b a n A r e a s : a d a p t i v e c o n s t r u c t i o n i s t h e m o t t o In view of the dynamic of the Maas and

Dordrecht, whose monumental city centre is located beyond the dikes, is experimenting with innovative

the uncertainty surrounding the rise in sea levels, development in areas that lie beyond the dikes would

initiatives that can be integrated into the current city. This does not only involve physical interventions (such

appear to be a risky undertaking. Still, living near water still is very attractive to the home consumer and

as flood timbers), but also coordinating aspects such as a high water warning system and a communications

is therefore of interest to developers as well. Rotterdam has a lot to offer in that respect. Where else in the

plan for residents (e.g. when and where do you get sandbags?). A number of matters must also be arranged

Netherlands can you live in an urban environment, while at the same time enjoy the vista of a river with tide

from a legal perspective: who sets the standards, what are the conditions governing liability, own risk and

fluctuations from your living room?

insurance?

In the Vierhaven and the Merwehaven harbour areas to the north and in the Rijnhaven and Maashaven

N e w a n d R e n e w e d H a r b o u r A r e a s : a f l o o d - p r o o f u n d e r ta k i n g Rotterdam harbour is undergoing

to the south there is room for a total of 10,000 homes. These homes represent a significant portion of the

major development. The plans for the Tweede Maasvlakte are the most prominent example of this. The rise in

goal to build 56,000 homes in the existing urban area before 2020, as described in the Rotterdam City

sea levels is a primary consideration in determining the building levels. But a lot is happening in the existing

Vision. Development beyond the dikes represents an enormous opportunity for Rotterdam, but only under

harbour as well. These areas are already situated significantly higher than the areas of Rotterdam within the

the proper conditions. Safety remains a primary concern. The measures that anticipate this dynamic and

dikes, although overall still not high enough. The Maeslant dam provides protection against sea tides; however,

the associated uncertainties posed by the river system are essential. From the very start (the Design), it is

river water could also generate excess waters in the areas beyond the dikes. Companies here are responsible

possible to provide for high water in areas beyond the dikes and to limit the impact of any floods. Special

themselves for placing critical components of their business operations (such as computers and other control

housing types come to mind in this regard, such as knoll homes, homes on piles, floating homes, ‘castle’

systems) at a safe, higher location.

homes, floating plots, etc. Furthermore, infrastructure-related measures could be taken, for instance to guarantee accessibility using flood bridges and mooring spots for water-based emergency services.

In anticipation of the development of the Tweede Maasvlakte, the harbour is being restructured. Companies are

Rotterdam is already familiar with public transport via water, but that too can be much improved upon.

being relocated, premises are being freed up and additional space is being created as a result of filling in some harbour basins. This restructuring creates an opportunity to make older segments of the harbour impervious to

Ex i s t i n g U r b a n A r e a s : i mp l e m e n t ‘ U r b a n H i g h W at e r M a n a g e m e n t ’ The combination of

high waters as well. This can be accomplished by raising the land, but other innovative methods are conceivable

existing urban areas beyond the dikes and higher water levels represents a thorny issue. Cherished

as well. In view of the uncertainties concerning which ground level measurement is in fact safe, it is a given that

residential are often involved or other areas where demolishing buildings in support of water damming

adaptive solutions should also be investigated. The large water surface area of the Waalhaven harbour could

measures is not an option. This would cost enormous sums of money and for all practical purposes would

possibly accommodate floating alternatives. Development of the harbour front beyond the dikes could also be

destroy the character of these areas. In other words: the remedy is sometimes worse than the disease. To

approached in an innovative way in this area. It would be a great opportunity for harbour operations to gain a

limit this risk, you can, in addition to reducing its probability, also reduce its impact.

high profile: the Rotterdam harbour remains operational, even during high tides!

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I m p l e m e ntati o n str at e g y Chapters 3 and 4 sketch out the perspectives as to how the municipality and the water boards intend to manage water resources and how this will make the city more attractive. One of the most important elements of this Rotterdam Water Plan 2, is as follows: How do we implement it?

And what do we need to do? What should we do first and what should we put off until later? These are all crucial questions. The central issue in this chapter consequently is the following: What is the implementation strategy for the elaborated vision? The following aspects are important for an implementation strategy: - The prioritisation and phasing of interventions; - Collaboration and organisation; - Costs and cost allocation; - Communication.

The above aspects are not put in that sequence by accident. From the 2000-2005 Rotterdam Water Plan evaluation it is apparent that the most successful projects meet a number of conditions: a sound and balanced set of interventions, clear planning and allocation of roles to ensure optimum collaboration, prearranged financing and support. This chapter will cover the various aspects of the implementation strategy in further detail and describes how we will reach the implementation stage. Chapter 6 will provide a more elaborate description of what will be implemented.

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5 .1 Prioritisation and Phasing

Chapter 4 provides an elaborate description of the 2030 Vision. The 2030 Vision meets the

objectives of the Water Plan 2: the resolution of the different basic water requirements and at the same time contributing to the creation of a more attractive city.

But the issue now is to formulate a proper implementation strategy, that sensibly deals with the sequence of things and that focuses on interventions that must be implemented over the coming years. The prioritisation and phasing process provides insight into which interventions must be implemented, and when, to realise the objectives of the Rotterdam Water Plan 2.

The 2030 Vision describes three different measures: - Interventions to improve the water system (water track projects). This involves the realisation of the basic water requirements, focussing on safety and the prevention of flooding, and the design of the system. Whereby sufficient attention is given to water quality, ecology and connections.

- Interventions that leverage the opportunities that are inherent in the water domain and that strengthen the urban quality to the maximum possible extent; and - Innovations and alternatives. Applicable where traditional approaches fall short and implemented were conditions are favourable.

These interventions are shown on the 2030 Intervention Map (see following pages). This map shows all interventions (not only the spatial planning ones) that contribute to the realisation of the objectives of the Rotterdam Water Plan 2.

The question then becomes: How do we get there? Which of these interventions, which all meet the criteria set out by the Water Plan should be implemented first? Two steps are important to be able to identify the priorities and the phasing. First, satisfy the negotiated agreements and goals, and second initiate the various initiatives required to fulfil these agreements and goals as efficiently as possible.

S t e p 1 : U r g e n c y o f Imp l e m e n t i n g 2 0 1 5 A g r e e m e n t s

Rotterdam and the Water Boards have formulated agreements that we are expected to fulfil by 2015. The year 2015 therefore is an important year. As such it requires that: - The current basic water requirements are solved in accordance with the Nationaal Bestuursakkoord Water (NBW) [Netherlands National Water Management Agreement]; - The water bodies meet the provisions of the EU Water Framework Directive (WFD); - The dikes meet current safety standards.

- It is therefore essential that we provide a clear overview that demonstrates that we are able to meet these conditions and that we identify the interventions needed to accomplish this. The 2015 Intervention Map was prepared for this purpose.

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W ATER TO B E A D D E D existing project project 2007-2012 project 2012-2015 project 2015-2030

Co n t r i bu t i o n e x t r a wat e r

( to r e q u i r e m e n t s p e r f i x e d wat e r l e v e l a r e a )

Storage capacity shortage more than solved Storage capacity shortage solved Storage capacity shortage to be solved between 2030 and 2050

RENVOOI

Wat e r q ua l i t y s o l u t i o n s

closing combined sewer overflow pumping station p ot e n t i a l wat e r b o dy a cco r d i n g to t h e E W F D W1: Schie met aantakkingen W2: Kralingse plas W3: Kreekse boezem W4: Boergoense vliet

fish migration conditions water storage and sedimentation basin S a f e t y m e a su r e s

regulation primary dykes outer dyke dynamical living environments

GENERAL

submerged water plaza shallow water plaza green roofs additional innovations subsurface water storage increased pumping capacity water discharge

Pag 121 Map IX Measures 2030

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S t e p 2 : C r i t e r i a f o r P h a s i n g I n t e r v e n t i o n s Using the 2015

The different projects are described in the following sections by basic water requirement type (safety,

Intervention Map, an in-depth assessment was carried out to determine

quantity and quality) and by implementation phase. The basic requirements, the projects that are already

which projects could be carried out, and when.

underway, the overall projects to be implemented during 2007-2012 and the research requirements are

A number of criteria was developed to assist in prioritising these

identified as well.

projects. The timeframe within which a project can be carried out depends on a large number of factors. If a project contributes to

S a f e t y M e a su r e s a n d R e s e a r c h R e q u i r e m e n t s In terms of water safety, the focus of this Water Plan

multiple sets of basic requirements, then the project should obviously

is on two main themes, viz. the dikes and development beyond the dikes. The basic premise for Rotterdam

be carried out ahead of a project that only meets one set of basic

is as follows: the city is and remains protected. Over the long term this means that decisions must be

requirements.

made concerning storm surge barriers and the desired heights of the dikes. This can only be discussed and approached in a forum in which all interested parties (ranging from the State to municipalities and from the

The following criteria were used to set priorities:

Directorate-General of Public Works and Water Management to Water District Boards) are represented. The

- Is the project already underway or not;

Water Plan’s partners therefore also take part in the Water Safety Programme, which is coordinated by the

- The degree to which the project contributes to the solution of

Province of Zuid-Holland.

one of the sets of basic water requirements (this is a question of scope); - The degree to which the project contributes to multiple sets of

For the implementation period covered by this Water Plan, the decision is to focus on strengthening the dike segments that do not as yet meet current standards. Testing of the Parksluizen has been completed. For 2015,

basic water requirements (a project that contributes to water

the only portion of the main dikes that requires attention is the dike near Vierhaven and Merwehaven. As

quality and water quantity scores higher than a project that solely

soon as the testing method has been established, work can start on performing detailed testing. In addition,

contributes to water quality);

the principle that applies is that there must be no barriers between different residential areas, but that a

- The degree to which the project contributes to making the city more attractive; - The degree of urgency, is it a question of now or never?

‘connected system of dikes’ must be implemented. These dikes form a bridge between the old regions located within the dikes and the dynamic water living environments in the large expansion regions beyond the dikes.

While at the same time reserving sufficient space to be able to strengthen the dikes in the future.

(Immediately exploit opportunities that arise); - The degree to which the project is a leading example.

In terms of the areas beyond the dikes, the possibility of flooding or other water excess and the associated consequences must be duly taken into account and safety must be maintained for the inner dike regions.

This approach was used to phase projects as follows:

An adaptive building and design approach must therefore be adopted with possibilities for evacuation and

- Project already underway;

communication with residents. This is why the Implementation Programme includes studies designed to

- Execute project between 2007-2012;

further develop the concepts mentioned above for implementation in a subsequent phase.

- Execute project between 2012-2015.

The projects and research requirements related to the safety theme for the following five years therefore are

- The 2015 Intervention Map identifies the interventions to be executed

as follows:

on a phased basis in order to meet national and international

- Perform testing of main dikes at Vierhaven and Merwehaven;

agreements.

- Carry out research into the potential for adaptive development in the Vierhaven and the Merwehaven

2 0 0 7 - 2 0 1 2 Imp l e m e n tat i o n P r o g r a mm e

- Approach to issue concerning building levels;

The Implementation Programme was derived from the phased

- Study into an adaptive method of building and design, possibilities for evacuation and communication

regions, and in the Rijnhaven and Maashaven regions in consultation with the involved parties;

projects identified on the 2015 Intervention Map. The 2007-2012

with residents concerning water safety.

Implementation Programme includes the following types of projects: - Ongoing projects;

W at e r Qu a n t i t y I n i t i at i v e s a n d B a s i c R e s e a r c h R e q u i r e m e n t s Over the coming years,

- Projects to be carried out in 2007-2012;

Rotterdam and the Water Boards will be faced with the task of storing more rainfall than is currently

- Research projects to be carried out in 2007-2012.

the case. Current issues related to water excess must be given priority in terms of their resolution.

Many initiatives in this regard have already been included in the Municipal Wastewater Collection Plan

The projects to be carried out in 2007-2012 speak for themselves.

(MWCP). To be able to withstand the peaks in precipitation due to climate change, space must be created

These are new projects which are expected to be completed during the

for storing water. Where possible this is done by creating areas with open water or by storing greater

next 5 years, in addition to the ongoing projects. The research projects

quantities of water in the wastewater collection system. Over the coming five years there will in particular

are projects that will be prepared for execution between 2012-2015,

be opportunities for excavating new water surface areas in the garden cities where there is restructuring.

on the basis of studies and research. The above classification has been

Examples of this are Groenehagen/Tuinhoven, Hordijkerveld, the north side of Lombardijen and Zuidwijk

maintained in the 2015 Intervention Map and was also used as a basis

(in conjunction with the Zuiderpark’s system) and the Oedevlietse Park.

for preparing the specific projects list in Chapter 8.

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In densely built-up urban areas where there is or will be little or no room, we are forced to focus specifically on

The approach within the planning period for this Water Plan then becomes as follows:

innovation and alternative forms of retaining water. Wadis, water plazas, vegetation roofs, water gardens, etc.,

- Develop and implement an integral plan of attack for the WFD bodies of water.

ensure that water is retained, stored and/or slowly drained so that it does not impose any additional load on the

- Develop and implement an integral plan for a select number of waterways. The waters that will be tackled

water system.

will be identified within the context of the municipal district water plans.

- The waterways that will not yet be dealt with on the basis of an integral approach must meet a certain

By designing and implementing these innovative solutions in such a way that they improve the living environment,

minimum quality. This means the lowest amount of floating refuse, number of complaints about stench

the implementation of an improved water system can contribute to the basic urban and social requirements of the

and fish mortality as possible. The water management improvements and the implementation of the water

city of Rotterdam. This is why the Implementation Programme includes a number of innovative leading projects

quality track as specified in the 2000-2005 Water Plan will be carried out.

such as water plazas and vegetation roofs, which partially solve water storage requirements, visibly improve spatial

- Research into opportunities for fish migration and the preparation of an integral fish stock management plan.

quality and are a source of experience for additional similar types of projects. These water plazas and vegetation roofs will initially primarily be installed in the densely built-up, compact urban area, in view of the fact that the

5 .2 Collaboration and Organisation

urgency here is greatest and the impact most noticeable. Pilot projects involving water plazas and green roofs will therefore be initiated over the next five years.

During the planning phase of the first water plan it already became apparent that the Rotterdam Water

However, the basic requirement, particularly the densely built-up city area is of such magnitude, that a few pilots

Plan is a highly efficient consultation forum. As a result, the water partners managed to book a number of joint

will not be sufficient. Particularly in areas where the current basic water requirements are high (City Centre, Oude

successes related to the execution of complex projects. In view of the fact that the Implementation Programme

Noorden, Crooswijk, Overschie and Oud-Zuid), significant additional energy, time and money will be invested in

foreseen by the current Rotterdam Water Plan 2 is even more ambitious, the level of collaboration will have to

further research to find a solution that addresses how the basic water requirements can be solved to an acceptable

be even more intensive.

degree during the following period.

The current organisation structure (workgroups, a project office, a steering committee and regular management The basic water requirements are also high in the Spaanse Polder and Noord-West industrial parks. A number

meetings) has proven to work well. A point of focus in this regard is the workgroups. In contrast to the previous

of measures will be implemented over the next five years (such as the excavation of certain areas to provide for

situation, they will be of a more ad-hoc character. A project team will be set up for each issue to be researched

additional water surface areas where possible, or alternative forms of water storage). However, the basic water

and once the result has been produced, the project team will be disbanded. It is of course essential in this

requirements are of such magnitude that further research is absolutely essential if a solution is to be implemented

regard that the research issues and project team assignments are well formulated. It is expected that a project-

by 2015. The projects and basic research requirements corresponding to the water quantity (or water storage)

based approach like this will produce results more rapidly and in particular will contribute to a dynamic and

theme therefore are as follows:

progressive execution process.

- Create new water surface areas in combination with the restructuring of the garden cities; - Create new water surface areas in industrial parks;

In comparison with the first water plan, two essential partners have joined the group, viz. the dS+V Department

- Implement the first water plazas and green roofs;

which is responsible for planning related to urban development, public housing and open spaces, and the OBR

- Further research for areas with a high current basic water requirement (city centre, old city districts and

[Rotterdam Development Corporation] for all matters related to the spatial and economic development of the city.

The Rotterdam Municipal Works department is responsible for managing the wastewater collection system, the

industrial parks); - Further research into wide water connections with the Koedoodzone (Midden-IJsselmonde).

municipal water policy, promoting the public interest and preparing for and executing technical interventions.

W at e r Qu a l i t y I n i t i at i v e s a n d B a s i c R e s e a r c h R e q u i r e m e n t s Rotterdam and the Water Boards want

New challenges include the alternative treatment of rainwater and the coordinating role related to ground water

to significantly improve water quality and the ecological water quality by 2015. This intent is first of all motivated

management. In other words: all municipal water activities. The municipal districts play an important role in

by the directives of the EU Water Framework Directive (WFD). Secondly, improvements in water quality also

managing/maintaining the open spaces. The Water District Boards remain responsible for water management: the

increase the quality of life, opportunities for use and the economic value. In addition, it results in management and

safety of the inner dike areas, water quality and quantity and the management of the water purification system.

maintenance savings.

As described in the previous chapters and as is evident from the Implementation Programme, an integral vision It is impossible to realise a completely clean water system within a 10-year timeframe. Not only are the costs

of these tasks has been developed as part of this water plan. This also requires a different review process from

involved in improving water quality extremely high, the water system is also somewhat sluggish and interventions

that used up until now. Consequently, the solutions to various basic water requirements were incorporated into

implemented today as a result can only have the desired impact over the longer term. This is why prioritisation

the City Vision and the Spatial Development Strategy during the planning phase. In addition, an analysis was

is key. By making use of the water quality modelling methodology we are able to identify interventions that are

carried out to determine the areas in which this development strategy is a determining factor for establishing

feasible, technically practicable and affordable. Furthermore, in relation to the various urban water types, the

the project execution phasing. This way optimal use was made of the synergy generated by the collaboration,

methodology helps in dealing proactively with the objectives and standards defined by the WFD for urban waters.

both in terms of the use of space, as well as financing.

The approach is used in particular for the municipal district water plans, because these plans include the water

M u n i c i pa l D i s t r i c t W at e r P l a n s ( M D W P ) The municipal district water plans currently are in the

flow levels and an optimal level of water quality can ultimately be achieved on the basis of the water quality

process of being executed, planned or being prepared, in all municipal districts. This is also true for those

models. The scale of the Rotterdam Water Plan 2 is simply too abstract for this purpose.

areas that are not part of a municipal district (e.g. the Oost-Abtspolder and the Spaanse Polder industrial parks). The primary consideration is that the interventions that are already being executed as part of, or that are incorporated into, the MDWPs must make a contribution to the resolution of the basic water requirements.

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5 .3 Costs and Cost Allocation

No remedial measures have been included anywhere. Furthermore it is of key importance to continue with the preparation and execution of the MDWPs because problems with the water system are already emerging and

require resolution.

The 2030 vision illustrates what the city could look like if water is used as an element that

contributes to the city’s goals. To develop a proper implementation strategy it is also essential to know The relationship between the Rotterdam Water Plan and the MDWPs is as follows: the water plan outlines the

what the costs are and how they are allocated. The cost of implementing the major portion of the basic

rural and urban limits and the city-wide vision that flows from it, together with the implementation strategy

water requirements by 2030 was calculated on the basis of key figures. These calculations show that the

required to achieve it. The Implementation Programme also includes a description of the large joint and other

costs of resolving the various sets of basic water requirements amount to between €400 and €500 million

projects, as well as the pilot projects, that transcend municipal districts (compare this with the Zuiderpark in the

up to 2030 (excluding future dike elevation).

2000-2005 Rotterdam Water Plan). The visions described in the MDWPs also fit under the overall umbrella of Of course it is impossible for Rotterdam and the Water Boards to generate this amount on their own.

the water plan.

Fortunately, they do not have to. It is a collective problem and various parties will have to bundle their The realisation of the Rotterdam Water Plan 2 target visions also requires many interventions that must be

resources to solve it. The State, the Province, the EU and corporations can all play a part. The skill involved

developed in further detail at the waterway level. These interventions will be (and to a partial extent already

in developing plans is to create sufficient financial and general support so that their execution becomes a

are) included in the municipal district water plans. This primarily involves sectoral water projects in support of

logical extension. The Water Plan looks for solutions that contribute to achieving the multiple and different

the resolution of problem areas, bringing the water system up to par and the additional focus on water quality

objectives of the participating stakeholders. This results in generating financial and general support and

and ecology in support of the EU Water Framework Directive (WFD) (and the associated focus on monitoring,

guarantees execution. We are looking for synergy (the whole is greater than the sum of its parts) that serves

management and maintenance).

as a basis for us as government agencies to be able to justify the execution of interventions from a social perspective.

In actual practice this means that a more detailed analysis is required to determine the completeness of the plans for the initial MDWPs (which are already in the process of being executed or for which planning is largely

Th e Ta s k Ow n e r Pay s , A c c o u n ta b i l i t y D e c i d e s An agreement framework has in the meantime been

completed).

developed based on the following key principle: the task owner pays. After all, this is also the basis on which the

In other words to ensure they are ‘WFD-proof’ and the basic quantitative water requirements (preventing

various levies (and therefore income) are calculated in accordance with the various goals of the organisation. In

flooding in the future) have been incorporated to an acceptable degree. Additional interventions that must be incorporated into the execution tables associated with the MDWPs may flow from this analysis. This clearly does not mean that the MDWPs must be completely revamped; instead it means the addition of one more research project to make the MDWPs water and climate-proof. In general the municipal districts will benefit from the increased urban quality that will result from the large-scale approach to the various basic water requirements.

P r o c e du r e s a n d A g r e e m e n t F r a m e w o r k District Water Boards and the Municipal Works, dS+V and

the Rotterdam Development Corporation are working together as members of the Water Plan organisation, but also maintain frequent contact outside this organisation. The water testing procedure and the mandatory water section to be included in the zoning plans, Wvo [Surface Waters Pollution Act] permits, inspection permits, etc., come to mind. By coordinating actions of this nature in the Water Plan organisation and incorporating them as part of procedures, it becomes possible to make significant efficiency gains.

One of the things that comes to mind here is the water test: if urban developers as well as city planners base their work on the basic conditions included in the Water Plan and the Water Boards assess the plans using a water testing procedure that is based on the Water Plan, then the results will match. This will shorten the lead time and result in high-quality plans. To safeguard the basic principles of this Water Plan a number of actions will be implemented over the short term, of which the most important ones are as follows: - Include the water prerequisites into the checklists for urban development and into the checklists for open spaces; - Verify the water section in the zoning plans with the vision contained in this Water Plan.

- Investigate whether it is possible to include conditions in the construction permits and development planning that are essential for achieving the Water Plan’s objectives.

Finally, in view of the enormous task and the corresponding intervention packages, annual reports to management will have to be made. In addition, the extent to which water quality, storage and safety objectives have been obtained will be monitored. The approach to accomplish this remains to be worked out.

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principle this means that the Water Boards pay for the interventions that contribute to water quality and water

interventions will improve the quality of open spaces, increase the value of living along water areas, and green

quantity targets. The city pays for wastewater collection interventions and is responsible for interventions within

roofs will have a positive impact on energy management and the particulate matter pollution problem, etc.

open spaces.

Furthermore, there is an increased emphasis on corporate social responsibility among such organisations.

The contribution of each party will depend on the urgency of the intervention. For example, in an area with significant

There definitely exists common ground that can serve as a basis for initiating partnerships. This is why

basic water requirements, the Water Board will contribute to the water excavations, but the city could have an interest

specific efforts will be made to find opportunities that lend themselves to joint project undertakings. A perfect

because the creation of water surface areas and disconnecting water flows will reduce the load on the wastewater

example of a successful public-private partnership is the ‘Pact op Zuid’, the South Pact, in which the City, the

collection system. In other areas, the creation of water surface areas could respond to spatial planning requirements

three municipal districts Charlois, Feijenoord, IJsselmonde, five residential corporations and the State jointly

and increase the quality of the environment. In that case the city will be the major stakeholder and the Water Board

are making significant investments to stimulate the development of open spaces, the living climate and social

could, for example, contribute on the basis of the premise that water quality is improved.

developments. There are links with these projects and the Water Plan as well.

The goals of the participating parties are related to the tasks. As mentioned earlier, surface water and water

The focus on water, specifically in relation to climate change, has increased tremendously over the last

quality are tasks assigned to the Water Board, and the City has a spatial development task and is responsible for

few years. This has also resulted in the creation of various grant programmes. For the time being grants

the wastewater collection system. For each intervention it is necessary to identify the objectives served. This then

are primarily being made available to carry out studies (such as the ‘Knowledge for Climate’ and ‘Living

becomes the basis for identifying how to allocate the costs.

with Water’ programmes), but the expectation is that over time people will come to the realisation that the enormous basic water requirements can only be addressed with the support of the State, if necessary

It is of key importance that all (joint financing) parties are involved as project team members from the very

on the basis of a modified Nationaal Bestuursakkoord Water [National Water Management Agreement].

beginning of each project. The different objectives of all organisations can be clearly established ahead of time.

Furthermore, there are the current grant schemes, such as those for dredging and for water beds (on the

The contribution to the individual objectives of the different organisations ultimately becomes the supporting

basis of which the province makes a significant contribution to the Kralingse Plas), as well as the future

framework for defining the financial contributions. The skill lies in finding common objectives that are

ISV [Urban Renewal Investment Budget] moneys. The latter is used for improving disadvantaged districts

supported, and financed, by different parties and that generate optimal synergy.

and restructuring, in which there is an increasing focus on the quality of open spaces. And on top of that, significant steps are being taken to implement the interventions defined in this Water Plan. Finally, a project

The water track interventions incorporated into the Municipal District Water Plans are apportioned on the

team will be set up during the next planning period that will devote itself to obtaining European grants.

basis of the principle described above. The costs allocated to each party are subsequently calculated by MDWP. In addition, an attempt is made to achieve a balanced distribution on the basis of prioritisation and selecting alternative interventions (at the most effective social costs).

Joint interventions involving water and spatial development primarily involve water storage projects. As provided for under the Nationaal Bestuursakkoord Water (NBW) [Netherlands National Water Management Agreement], the Water Boards are responsible for the excavation of the water storage areas needed on the basis of the calculation of the basic water requirements. In these projects, the City makes the grounds available free of charge (provided this fits within the spatial planning policy of the City and exclusive of the costs of relocating facilities).

The design of the open spaces and the excavation of additional water surface area in addition to the basic water requirements are in principle at the cost of the developer and/or the City. Elements such as cables and pipelines, soil remediation and archaeological sites in the soil’s substratum could result in additional project costs. These elements, if they are not already included in the cost of the project, will be more specifically allocated.

Innovative interventions (pilots) are new and therefore require custom work. However, a few basic principles apply: the extent to which these interventions contribute to the resolution of the basic water storage requirements in any given area is easily calculated. Based on the average statistics for this type of urban region, an amount per m3 of storage space can be agreed upon that the Water Boards will contribute to the intervention.

The City retains responsibility for the development of the open spaces.

In general, for city-wide studies and analyses the following Water Plan allocation applies: 40% for the City and 25%, 25% and 10% respectively for the Hollandse Delta Water Board, the Schieland & Krimpenerwaard Polder Board and the Delfland Polder Board. The involved parties will contribute to the other research projects on a prorata basis.

P ub l i c P r i v at e Pa r t n e r sh i ps Indeed, the basic water requirements are the responsibility of the parties to

which these tasks are assigned. Nevertheless, private parties such as residential development corporations and project developers will also increasingly derive benefits from the implemented interventions. For example, the

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‘It all star ts with the right information…’

Integrated policies for sound water management require adequate contact between citizens and government. “We know a lot about the situation on the streets and in neighbourhoods,” says Marion Vredeling of the Bewonerswerkgroep Wateroverlast (Residents’ Working Party on Flooding). “Government policies that are based on such a wealth of knowledge will be more effective, and will be better supported and understood.”

As the co-founders of the Residents’ Working Party on Flooding, 65-year-old

Jan Buijs and Marion Vredeling, 52, are closely involved with the problems and developments related to flooding. Through contacts in the scientific world

and through home study, they have built up a treasure of information about

the problems in their own neighbourhood and, thanks to a survey performed with the help of the Steunpunt Wonen (a service centre for residents) about the situation elsewhere in Rotterdam.

“We hope that citizens and the municipality will be partners in the future,” says Vredeling, whose house on Schietbaanlaan was affected by serious flooding on several occasions. We should keep each other better informed about the actual problems caused by flooding including all the secondary issues associated with it, including building problems, legal problems, and policy issues. “ “Hopefully such a partnership will quickly get off the ground, because effective policy starts with all parties being properly informed. About

essential matters like duty of care and liability, for example. It is now often

the case that residents do not know what to do when they find their kitchen or cellar suddenly flooded. Some people take their own measures which may

work for them, but which may prove detrimental for the surroundings.” Buijs too believes that an ‘open relationship’ between the local authority and

citizens should be given priority. “Of course the city wants to restrict flooding as far as possible, just as we do. But let’s tackle it together, and explain to each other what we are doing, and why.”

Vredeling and Buijs see a parallel between the worldwide fight against

climate change and dealing with a problem like local flooding. Vredeling says, “You can only be effective if your macro view is consistent with findings at

micro level. Only then will you gain support, a social basis and a substantive

focus in order to be able to achieve something. We would like to do our bit as well.” The knowledge capital that these highly committed citizens possess is

therefore an asset that is there for the taking. Buijs concludes, “What I would like to say to the council is this: don’t regard us as a campaign group, but as

knowledge-bearing citizens, and let us learn from each other’s experiences.”

“Most importantly, let’s act together”

Mario n V r e d e li n g e n ja n b u ijs : ‘ T H E C I T I Z EN A S A F U L L Y F L ED G ED P A R T NE R ’ 130

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5 .5 Communication concerning

the Rotterdam Water Plan 2

The Rotterdam Water Plan 2 is a model project: water management authorities and spatial planning experts in Rotterdam are joining hands to develop solutions to the specified basic water requirements. With a new outlook: start off with the opportunities inherent in water instead of with a focus on the problems that come with water. The Water Plan is a results-oriented plan with the emphasis on execution.

Communication plays an important role throughout the duration of the Rotterdam Water Plan 2. Not only is it important for professionals to find one another but it is also important to inform residents, companies and clients and incite enthusiasm for the creation of a good water system for Rotterdam.

P r o j e c t C o mmu n i c at i o n s du r i n g W o r k A c t i v i t i e s The focus of communication with citizens is

primarily on project communication. We intend to inform Rotterdammers on a timely basis with accurate information about work activities or ‘water projects’ in their neighbourhoods. The municipal district takes the lead in this respect. They will be distributing letters to residents and generating attention in the media. In addition, citizens will be able to express their opinions during evening information sessions for residents. Information about work activities or information about the ‘water intervention’ are key project communication elements. In addition, information about water in general and the Rotterdam Water Plan 2 in particular are important components. The central communication team, which includes representation from all involved parties, facilitates the municipal district water plans using standardised communication plans and formats.

C o mmu n i c at i n g t h e Imp o r ta n c e o f W at e r t o t h e C i t y Citizens will show greater understanding

for implementation activities when they are familiar with the relevant background: when they are aware of the importance of sound water management. We want Rotterdammers to be aware of what the various government agencies are doing and what they can do themselves to prevent flooding. The communication team will use various mass media resources for this purpose: general information materials and attention in newspapers, on radio and on TV. In addition we want to initiate actions focused on residents: involve schools and try to promote interaction in different ways with residents and companies. Innovative projects such as water plazas and green roofs serve as stepping-stones in this regard.

C o mmu n i c at i o n w i t h P r o f e ss i o n a l s Good communications are also important in relation to

professionals: government, provincial, municipal and water board managers and project executing bodies.

The project organisation itself forms the basis for mutual communications. A website with general and project information will be available as a support tool. A protected portion of the website allows relevant documents to be shared and provides access to member contact information. The communication team will issue newsletters and specific excursions to provide involved parties an overview of Rotterdam Water Plan 2 activities that are underway. The communication team facilitates and maintains the resources; all of the involved parties provide input. To create unity, the internal communication team uses the term Rotterdam Water Plan 2 as its central focus.

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i m p l e m e n tat i o n PROGRAMM e 2 0 0 7- 2 0 1 2 The aim of the implementation programme is to

continue on the route taken when the first water plan for Rotterdam was being formulated. At the same time, we are implementing projects in cooperation with Spatial Planning and are making sure that the solutions for good water management in combination with an attractive living environment include innovative alternatives. In addition, after 2012 we want to realise the basic water requirements quickly; so we are now organising and preparing all the projects.

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6.1 Implemented projects

W e s t e r n H a r b o u r a r e a ( W e s t e l i j k H a v e n g e b i e d ) The main focus in the 2000-2005

Rotterdam Water Plan was on constructing the wastewater collection system in the Western Harbour area. The wastewater chain is now practically finished there, which means that both the wastewater collection system and the wastewater treatment system are almost in full working order. All we have to do now is analyse what we have to do to make this area completely ‘waterproof’; so we are formulating and particularly implementing intervention plans for water quantity, water quality and particularly water safety aspects. This activity will be tackled in the coming planning period, analogous to drawing up the municipal district water plans.

Zu i d e r pa r k ( W S H D 1 . 2 3 ) A master plan has been drawn up for the Zuiderpark with the aim

of transforming it into a park of the 21st century. This means that the park must be accessible and usable for a large part of the population of Rotterdam in all its diversity. In terms of the water system, the aim is to realise a huge increase in the storage capacity (from 21 to 35 hectares of open water), combined with a forward-looking layout that ensures that ecology and recreation go hand in hand. In other words: a water treasure for Rotterdam South. Based on this nucleus, the water system in Rotterdam South will take further shape as described in Chapter 4. This programme is being tackled with vigour and it will be ready during the planning period of this water plan.

C a n a l p l a n ( S i n g e l p l a n ) The canal plan is a long-term programme aimed at refurbishing

a number of existing canals and streams in North and South. Among others, the canal plan comprises the canals in the Rose Plan. Besides refurbishing the outside space around the canals (green areas and streets), the canal plan also focuses on improving the water quality. During the past few years, Bergsingel, Noordsingel, Crooswijkse singel and Boezemsingel have been tackled. In the years to come, the same activities are planned for Spoorsingel, Provenierssingel, Boergoensevliet (WSHD 1.2) and the extended Lepelaarsingel (WSHD1.3). Depending on the results of water quality surveys, additional measures will be drawn up for the water system on the basis of the water plan.

Provenierssingel and Spoorsingel are located to the north of Central Station. Part of the plan for that north side of Central Station includes the construction of a new section of open canal (including a bridge) between Spoorsingel and Provenierssingel. As well as this, additional water storage will have to be created to accommodate the drainage from the huge new station roof (3 hectares) over the tracks and platforms. It may be possible to construct this in the form of a connecting canal from Provenierssingel to Statensingel.

Pa r k Z e s t i e n h o v e n The municipal district of Overschie includes the large new development

area of Park Zestienhoven in the Zestienhoven polder. In the development of this newly-built quarter, water has an important role to play in all phases of the planning process. In the years to come, the water system will be adapted and installed at the same time as the residential area is being built. The combination of a well-designed water system and a properly functioning wastewater chain should ensure that (most of) the

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components of the water system will satisfy the water quality objectives. One particularly striking element

M u n i c i pa l d i s t r i c t w at e r p l a n f o r O v e r s c h i e We started formulating the plans in 2007.

of the plan is the realisation of a broad main watercourse with a nature-friendly bank on one side. This

The plans will focus on both the water quantity requirement (50,000 m3 in 2007) and the water quality.

main watercourse and the bank are part of an ecological link.

B e r g s e P l a ss e n The integral recovery plan for the Bergse Plassen has almost been completed.

M u n i c i pa l d i s t r i c t w at e r p l a n f o r H i l l e g e r sb e r g S c h i e b r o e k We started formulating

the plans in 2007. In this municipal district, there is an ongoing integral recovery plan for the Bergse

The combination of measures, such as dredging, constructing the wastewater collection system, improving

Plassen and a number of adjustment measures for a new discharge route that bypasses the Bergse Plassen.

the design, dephosphatising the intake of the canal water from Hillegersberg, managing the fish stocks

There are no basic water requirements in the municipal district. The plan will therefore particularly focus

and creating pike spawning locations, seems to be bearing fruit. For example, water visibility has already

on the water quality of the other waters in the municipal district.

increased from 20 centimetres to over one metre. During the coming planning period, the final measures will be completed, such as isolating the lakes by constructing a discharge route for the water from the

C e n t r um W at e r P l a n The Centrum Water Plan has been ongoing since 2002. The reason why

residential areas that bypasses the lakes. Once that is done, the emphasis will mainly be on monitoring the

the plan was drawn up was the flooding caused by extreme rainfall. The plan is therefore particularly

development of the lakes.

focused on reducing the basic storage requirement in the area. Prior to defining the total package of measures for the centre, in 2004 a positive decision was taken for the construction of an underground

A c t i o n p r o g r a mm e P e i l 2 0 1 0 i n R o t t e r d a m Since 2002, the ambitious Peil 2010

water storage facility. This storage capacity of 10,000 m3 will be integrated into the new parking garage in

programme has been up and running in the management area of the District Water Control Board of

Museumpark.

Schieland and Krimpenerwaard. The programme is aimed at resolving the main bottlenecks in water quantity management within a short time. In Rotterdam, too, over the past years several projects

R e m a i n i n g m e a su r e s i n c o r p o r at e d i n t o t h e C e n t r um W at e r P l a n After the measures

have been prepared and partly implemented. These involve a new pumping station, including a supply

have been implemented, the negative effects of wastewater overflows will be reduced considerably

watercourse, for the areas of Ommoord and Nieuw Terbregge. A new pumping station on the edge of

and (some of) the water will satisfy the water quality standard for canals. Of the current basic water

Prinsenland near the Capel neighbourhood of Fascinatio with an improved discharge route from Kralingen

requirements of 38,000 m3, the implementation of this plan will realise approximately 20,000 m3. In

along ’s Gravenweg. A new discharge route from Hillegersberg Schiebroek to the new pumping station

addition to the measures specified in the Centrum Water Plan, in the area of the centre a pilot for a water

in the Bergsche Bos. Over the coming period, several other small projects will also be initiated, such as

plaza and a vegetation roof will also be implemented. After this is up and running, that will leave a basic

replacing and augmenting the Westersingel canal pumping stations (part of the Centrum Water Plan), the

water requirement of approximately 18,000 m3, increasing to 30,000 m3 in 2050. In the centre there

Noordsingel pumping station, the Boezemsingel pumping station and a possible new pumping station to be

are few other options for the creation of extra surface water. The area of the centre is therefore also the

built in Roel Longrak Park.

research area for a pilot for a water plaza and the use of green roofs.

M u n i c i pa l d i s t r i c t w at e r p l a n f o r D e l f sh a v e n In Delfshaven, work began in late 2006

M u n i c i pa l d i s t r i c t w at e r p l a n f o r K r a l i n g e n C r o o sw i j k The municipal district water

on drawing up a municipal district water plan. The Delfshaven water plan will focus on the interaction

plan is currently being formulated. The inventory phase has now been completed. The area is particularly

between surface water and wastewater, the basic storage requirement in relation to the high percentage of

affected by water quality and groundwater problems. Both the Esch and Crooswijk have basic water

hard surface and the sub-standard water quality.

requirements. In the Esch, the basic water requirements will be researched in more detail. For Crooswijk, a research study will be launched into the possibility of building new canals. For Kralingse Plas, an integral

W at e r s t ud y O r a n j e bu i t e n p o l d e r ( H H D 5 ) The project for the refurbishment of

recovery plan is now under development. Implementation begins in 2008.

Oranjebuitenpolder is aimed at strengthening the nature and recreation function in this area and so turn it into an important part of the scenic and recreational zone of Coast - Staelduinse Bos – Oranjeplassen -

M u n i c i pa l d i s t r i c t w at e r p l a n f o r P r i n s A l e x a n d e r The first phase of the Water Plan,

Midden Delfland. One of the components to be worked out is a water plan that gives an accurate impression

an inventory of all ongoing improvements of the wastewater collection system and water system, has

of the water management situation and the opportunities for realising a brackish water environment.

been completed. The measures include a new pumping station in Ommoord, including adaptations to the drainage watercourses and culverts in Ommoord and Nieuw Terbregge and a large new wastewater pumping

S c h i e v e e n W at e r P l a n ( H H D 6 ) The Schieveen Nature and Business Park is under development

station. In addition, the newly-built Nesselande quarter, including the expansion of Zevenhuizerplas,

in the Schieveen polder. The element of water is the underlying theme in this development. The water

is being rapidly developed. In the next phase of the water plan, it will be determined which additional

plan describes the main outlines of the water resource management design for the polder and specifies the

measures are necessary. The municipal district has no basic water requirements.

preconditions and the objectives for the further elaboration of water management in the design plans to be formulated. This involves aspects such as realising water and natural areas with water and possibly a

M u n i c i pa l d i s t r i c t w at e r p l a n f o r H o o g v l i e t The Hoogvliet municipal district water plan

collection basin for calamities. This regional plan will be drawn up in the next few years.

was drawn up in 2002. The plan was formulated to boost both the water quality and to prevent major rises in the water level in the area. The basic water requirements have not yet been included in this plan. The

D r a i n a g e c h a n n e l i n M at l i n g e w e g ( H H D 8 . 2 ) In the context of the restructuring of

measures mainly relate to the adaptation and relocation of wastewater overflows and the improvement of

Spaanse Polder industrial zone, to the north of Vlaardingweg on the southern side of the channel along

the water system, which will make it possible to flush through the system more efficiently (larger culverts,

Matlingeweg, an extra area of water storage will be excavated.

larger intake). The launch of the measures was delayed by a debate about the distribution of costs. In 2004, agreements on the distribution of costs were signed and in 2005 the water plan and the distribution of costs for the measures to be implemented up to 2012 were approved. The progress of the implementation is being evaluated on an annual basis.

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M u n i c i pa l d i s t r i c t w at e r p l a n f o r I J ss e l m o n d e The plan was drawn up in 2003 and

- Duty of care for groundwater. Water Boards and the municipality are being confronted with changes

consists of a list of measures to be implemented over the 2004-2006 period. In addition, a proposal was

in their responsibilities for dealing with groundwater. In the new legislation, the municipality will

submitted for the implementation of measures after 2006. The measures for the short term mainly relate

be responsible for control. To facilitate this, a ‘dealing with groundwater’ project team has been

to technical activities and research measures. Just some of the measures have so far been implemented.

established in the organisational structure of the Rotterdam Water Plan. This team will focus on

The measures will continue to be implemented and new agreements will have to be made on financing the

formulating and activating new policy in this area.

follow-up to the water plan.

M u n i c i pa l d i s t r i c t w at e r p l a n f o r Ch a r l o i s / F e y e n o o r d The water plan has been

M a n a g e m e n t a n d M a i n t e n a n c e Although investments in new projects and alternative

strategies are of vital importance, in the field of water management a good management and maintenance

subdivided into short-term and long-term measures. Short term measures relate to the planning period

regime is essential. That regime is already largely in place and is functioning satisfactorily, but there are

(implementation 2005-2009) and focus on adapting culverts (technical measures) and constructing

still a number of spearheads for which specific attention is necessary in the coming period.

new watercourses. The measures in the municipal district of Feyenoord fall largely outside the planning period, because the high costs mean that every advantage must be taken of any opportunities that present

themselves (plans of third parties, restructuring).

was made in dredging the watercourses, partly to make up for overdue maintenance and partly to pay for

D r e d g i n g During the planning period for the first Rotterdam Water Plan, a major investment

extra quality dredging. That objective has now been achieved. To do this, optimal use was made of the

M u n i c i pa l d i s t r i c t w at e r p l a n f o r P e r n i s Given the isolated location of Pernis, for this

Subbied subsidy scheme. Following the evaluation of this scheme and the new developments in the area of

area it was decided in consultation with the neighbourhood council to formulate a separate water plan. The

riverbed policy, during the current planning period a new dredging policy and associated implementation

water plan was drawn up in 2005. The measures mainly relate to measures to improve the current water

will be introduced. The main consequences are:

system.

- Harmonisation of the supply and demand for dredgings, therefore the local reuse of dredgings as

M u n i c i pa l W a s t e w at e r C o l l e c t i o n P l a n ( “ GR P ” ) In 2006, the Municipal wastewater

much as possible.

collection plan 2006-2010, which specifies the wastewater collection policy for the coming years, was

- Research into the possibilities for a new division of roles in the area of dredging. A new division of

approved by the council executive. The plan stipulates the basic requirements for wastewater collection

roles should lead to lower social costs and prevent any dredging arrears in the future. The Water

management, which are closely related (in terms of both water storage and water quality) with the basic

Boards may want to take over the dredging of the other watercourses from the municipality. In return,

water requirements that are examined and specified in this Rotterdam Water Plan 2. The financial

the municipality will have to formulate a plan that makes it possible to have processing locations for

consequences of the proposed policy were also mapped out. That makes the GRP an important mainstay of

dredgings. During the planning period of Rotterdam Water Plan 2, a ‘dredging’ project team will be

this water plan. The main results of the GRP are:

appointed that focuses specifically on the above themes. This will result in an implementation plan that is supported by all the parties involved and in which agreements are made about dredging in the future.

- The increase in wastewater pipeline replacement is on track. The amount of pipeline to be replaced every year must increase considerably (from 14 km in 2000 to 40 km in 2010) to keep the function

and the quality of the wastewater collection system up to standard. An evaluation has shown that

Directive) and the water quality requirement, it is vitally important to focus on the management of the fish

this is the right strategy. Despite the high costs of such an increase in the replacement of wastewater

stocks. This is because the fish stocks (species and amounts) largely determine the extent to which water

pipelines, every effort will be made to achieve this.

quality objectives can be achieved (see also the ‘Water quality’ section in the ‘Vision’ chapter). During the

- The groundwork has already been realised. Due to the introduction of the Central Automatic Control

M a n a g e m e n t o f f i sh s t o c k s Based on the European legislation (the Water Framework

coming planning period, a specially appointed ‘management of the fish stock’ commission (“VBC”) will

(“CAS”) of the wastewater collection system, the wastewater in the wastewater collection system can

therefore draw up an inventory of what is necessary to arrive at an optimal mixture of measures and policy

be distributed more efficiently, and this has a major positive effect on the storage in the system (and

to guarantee that the fish stocks are compatible with Rotterdam’s water system and do not stand in the way

therefore on the prevention of wastewater overflows) and the supply to the treatment plants.

of achieving the water quality objectives.

- 100% connection to the wastewater collection system is close to completion. According to the nationwide agreement, all untreated discharges (in this case, premises that still do not discharge

M o n i t o r i n g In 2003, a zero measurement of the water system in Rotterdam was performed, with the

their wastewater via the wastewater collection system) should be put in order ─ that is, ‘duty of care’.

focus on the water quality. This report provided vital information and is now therefore being used as a

Apart from the situations for which the Provincial Government has granted an exemption, this will be

frame of reference. The results particularly show that the water is rich in nutrients, is contaminated by

realised during the current period, which means that almost 100% of all premises will be connected to

heavy metals and that the condition of the flora and fauna is sub-standard. At the same time, it is clear that

the wastewater collection system.

there are opportunities for designing water systems, increasing water surfaces and constructing nature-

- The innovative use of rainwater. Both climate change (as a result of which more frequent and more

friendly banks. As part of the water plan, a progress report will be made every year on how the water plan is

intensive downpours are expected) and social/legal developments have shown that rainwater must be

being implemented. This involves both the physical progress (which projects were implemented, how much

studied in more detail and must be tackled in an alternative way. By separating dirty and relatively

storage was realised) and the financial progress.

clean water, the wastewater collection system and the treatment plant will operate more efficiently

The second comprehensive water quality and ecological monitoring will be conducted in 2010. The next

and flooding and problems with water quality will be reduced or prevented. Where this water plan

water plan can be formulated on the basis of the results.

proposes alternative ideas such as water plazas and green roofs, in the GRP it is also assumed that wastewater and rainwater will be segregated, particularly in the case of wastewater pipeline replacement and new construction projects. The extra costs that this entails will be largely covered by the (expanded) wastewater collection charge.

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I M P LE M ENTATION P ROGRA M M E 2007-2012 project 2007-2012 project 2012-2015

research and studies 2007-2012 green roof programme pilot water plazas contribution of the projects to:

water safety requirements

water quality requirements

water storage requirements

attrective city requirements

RENVOOI

Water quality solutions

closing combined sewer overflow pumping station potential waterbody according to the EWFD fish migration conditions water storage and sedimentation basin Safety measures

regulation primary dykes outer dyke dynamical living environments General

submerged water plaza shallow water plaza green roofs additional innovations subsurface water storage increased pumping capacity water discharge

Map X Measures 2015

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6.2 Coalition projec ts and innovations

By using water as an opportunity to improve the living environment, the basic water requirements and the realisation of a better water system will contribute to the social requirements of the city of Rotterdam.

I n f i lt r at i o n / a lt e r n at i v e w at e r s t o r a g e M at l i n g e w e g ( H H D 8 . 6 ) To improve the water

quality even more, restructuring will provide opportunities for disconnecting and infiltrating the hard surface or storing and draining away water underground.

P o l d e r Oud - M at h e n e ss e ( H H D . 9 . ) The Oud-Mathenesse polder is a post-war residential area

characterised by a high degree of asphalt (43%) and a low degree of green areas and surface water. Polder Oud-Mathenesse is an overflow-drainage area. In this area, rainwater is drained away almost completely

Coalitions with spatial actors in the city will provide the ideal opportunity for actually realising the total

by the wastewater collection system and the overflow drainage, and hardly at all by the polder pumping

basic water requirements. And that is exactly what is going to happen in the coming period. For all of

station on Spaanseweg. The bottlenecks in the polder are the shortage of water storage, drainage of the

Rotterdam, it has been examined which spatial projects will be implemented in the period 2007-2012 and

surface water through the mixed wastewater collection system to the wastewater treatment plant, and the

how much surface water could actually be realised in these projects. In doing this, some of the basic water

related sub-standard quality of the surface water. In addition, the presence of long culverts is causing bad

requirements will have to be realised in an innovative way because the requirements in combination with

throughflow and sub-standard water quality.

the pressure on urban space are so extensive. We will also ensure that projects are prepared in such a way that they can be implemented quickly after 2012 in order to realise the urban requirements and the basic

C o n s t r u c t i n g w at e r s t o r a g e f a c i l i t y i n Tj a l k l a a n ( Pa r k L a n e ) ( H H D . 9 . 2 ) Tjalklaan

water requirements.

in the Oud-Mathenesse polder is being reconstructed to improve the traffic throughflow. In the planning

Description of implementation projects planned for 2007-2012

area, there are opportunities for realising extra water storage and in that way reducing the storage shortage in the rest of the polder. Under the metro line, 3,000 m3 of new surface water can be realised. This will partly resolve the storage shortage in the polder and greatly improve the throughflow in the water system.

G r e e n r o o f s At a number of different locations, we are starting a feasibility study into the

large-scale application of green roofs and the realisation of demonstration projects. From the perspective

W at e r p l a z a i n S pa n g e n ( H H D 1 0 o f 3 3 ) The district of Spangen is characterised by a high

of water storage, the focus is mainly on the densely-built urban areas in which it is almost impossible to

percentage of hard surface and few opportunities for realising surface water. As yet, the district has no

excavate for water: Centrum, Oude Noorden, Crooswijk, Overschie and Oud-Zuid. In addition, green roofs

basic water requirements. During restructuring activities, there will not be many opportunities for realising

will be stimulated in the industrial zones of Spaanse Polder and Northwest.

new surface water. However, the construction of a water plaza on Aagje Dekenstraat will enable developers to realise the basic water requirements in combination with the basic urban requirement. In addition, the

O o s t - Ab t sp o l d e r ( H H D . 7 ) In the Oost-Abtspolder, there is a 15,000 m3 shortage of surface

water plaza will also improve the water quality.

water. In addition, there are a number of low-lying areas that regularly suffer from flooding. Given that the industrial zone is relatively new, there are no large restructuring projects taking place in the polder. For

T e s t i n g t h e V i e r - e n M e r w e h a v e n m a i n f l o o d d e f e n c e s As soon as the testing method

this reason, it will be difficult to realise new surface water in the short term.

for testing the safety of the main flood defences along the Vier- en Merwehaven is available, the necessary tests will be carried out.

I n n o v at i v e u n d e r g r o u n d s t o r a g e i n O o s t - Ab t sp o l d e r ( H H D . 7 . 1 a n d H H D 7 . 2 ) The

ground level is being raised locally, however, and streets are being redesigned because of subsidence that

has occurred. To realise part of the basic water requirements, in the road drains innovative technologies

Noorden and the surrounding areas have enormous basic water requirements. Although the options for

M u n i c i pa l d i s t r i c t N o r t h ( H H S K . 2 . 1 t o 2 . 5 ) In the municipal district of Noord, Oude

can be used to store water, in combination with disconnecting the hard surface.

expanding surface water are being researched, the requirements will never be completely realised using surface water. The only surface water in this area consists of Bergsingel and Noordsingel. These canals are

P o l d e r S pa n g e n ( H H D 8 ) The main bottleneck in the water system in the Polder Spangen (the

being very adversely affected by the wastewater overflows in this area.

Spaanse Polder industrial zone) is that there is not a great deal of surface water, which means that when there is heavy rainfall it can cause an impermissible rise in the water level. Surface water is partly drained though

For Noordplein, preparations are under way for the construction of an underground parking garage. This

the mixed wastewater collection system. This is undesirable from the perspective of sustainability and water

construction work could be combined with the construction of both underground and above-ground water

quality. The water quality in the area is sub-standard due to the presence of overflows, illegal discharges, the

storage facilities. The underground storage could consist of a storage settling tank of several thousand

erosion of roads and a lack of throughflow.

cubic metres. This could greatly reduce the emission of pollutants through the wastewater overflows.

Moreover, the tank could also contribute to the basic storage requirement in the area. On street level, the

In the years to come, the industrial zone of Spaanse Polder will be intensively restructured with the aim of

square could be developed into a water plaza. This could turn the square into an important pilot project for

achieving a more sustainable use of space. This will provide opportunities in the Spaanse Polder for realising a

the use of these plazas in Noord. Pilots with green roofs will also be implemented in Noord.

cohesive and integrated water system with a greater self-cleaning capacity and sufficient throughflow.

The pumping station on the Noordsingel will be replaced by a pumping station with a larger capacity. For (part of) the Kleiwegkwartier, work is commencing on the creation of a new discharge route in the direction

C o n s t r u c t i n g w at e r s t o r a g e f a c i l i t y i n S pa a n s e P o l d e r i n dus t r i a l z o n e

of Hillergersberg, where additional water storage will be realised where necessary.

( H H D . 8 . 1 , 8 . 3 , 8 . 4 a n d 8 . 5 ) Expanding the surface water to Industrieweg, developing water in the

surroundings of Vliststraat, developing water in the axil of the slip road from the A20 motorway (close to

Giessenplein) and expanding the existing watercourses on the Van Nelle terrain will increase storage in the

commencing on the construction of a storage settling tank. In Schuttersveld, a pilot is being implemented

area and improve the possibilities for drainage and supply.

for a water plaza.

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S t o r a g e s e t t l i n g s y s t e ms w at e r p l a z a i n C r o o sw i j k ( H H S K 3 ) In Crooswijk, work is

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Add i t i o n a l m e a su r e s c e n t r e ( H H S K 4 . 4 A & B ) Supplementary to the measures in the

zones and the sub-standard quality of the surface water, it was decided to expand the water system from 2.5 to

Centrum Water Plan (section 6.1), a pilot for a water plaza is being implemented at ‘t Landje and a number

5.15 hectares. In the plans, a canal runs through the district, along which several play and recreation areas will

of green roofs are being constructed.

be constructed. The south will have water with a natural character that is part of the ecological east-west zone of the municipal district of IJsselmonde. This is water along which nature-friendly banks are being created, where

K r a l i n g s e P l a s ( H H S K 7 ) With approximately 2 million visitors every year, Kralingse Plas and

people can go fishing and walking, and along which utility parks can be situated. The development of water will

Kralingse Bos are two of Rotterdam’s main recreation areas. Following the work carried out to improve the

make the lots located there even more attractive. The project will start with the construction of the first phase of

Bergse Plassen, in 2007 work started on drawing up an integral recovery plan for Kralingse Plas. This plan

the canal in the community garden of Hordijkerveld. The client for the design plans in Hordijkerveld is Vestia

is aimed at improving the water quality, ecology and recreational use of the lake. Dredging is a major - and

housing corporation, which is also responsible for the land development.

expensive - part of the plan. With regard to the dredging, particular attention will be paid to the local use of the dredgings. Other parts of the plan include improving the bank structure and the fish stocks.

P e r n i s V e r m a e t w e g ( W S H D 1 8 . 1 ) There is space for extra water in the area to be refurbished.

The development of extra water will satisfy the basic water requirements and help to upgrade the outside N o r t h e r n e d g e o f Zu i dw i j k ( W S H D 1 . 1 3 , 1 . 1 5 , 1 . 1 6 a n d 1 . 2 1 t o 1 . 2 4 ) In this area, new

space in Pernis.

residential habitats are being realised in combination with new surface water and improvements to the public space. There are currently no canals in this part of Zuidwijk, so the disconnection of hard surfaces

O e d e v l i e t s e pa r k H o o g v l i e t ( W S H D 2 3 . 1 ) In the park, part of the compensation requirement

in the new situation or the introduction of an improved segregated system is also being studied. This will

for the restructuring activities will be achieved. In addition, dry peak storage in the form of multiple use of

be enough to resolve the basic water requirements. Another objective is to improve the quality of the water

space will be sought. Water storage and living close to the water are important features of the park. It will

system (elaborating on and linked to the clean water system of the Zuiderpark). This project is part of the

be researched whether recreation and water and a water-based botanical garden are usable for the park.

“Southern garden cities” pilot project of the Ministry for Housing, Spatial Planning and the Environment.

The effect on the park of a peak load caused by a downpour will also be researched.

K r e e k s e b o e z e m ( W S H D mu n i c i pa l d i s t r i c t I J ss e l m o n d e , w at e r b o d y ) The main

W at e r p l a z a Oud - Zu i d ( W S H D 2 ) In Oud-Zuid, the densely-built area in the municipal district of

Feyenoord has a large basic water requirement. Given the basic water requirements for 2015 and the scale of the

objective for the Kreekseboezem water body is to improve the water quality by disconnecting the

building density, innovative solutions are required. A water plaza that makes a major contribution to the basic

wastewater overflow from the drainage water and connecting it by means of a discharge pipe to the river.

water storage requirement (deep plaza type, linked to the wastewater collection system) is one solution that can

In addition, the Kreekseboezem will be dredged and the clean water from the river will be used to flush

solve a relatively large part of the problem. When it is linked to the wastewater collection system, the overflow

the park De twee heuvels. Therefore step 1: clean Kreekse drain. Step 2: more water in park De twee

on the Lange Hillevliet can be closed. This will improve the water quality of the Hillevliet. In addition, water

heuvels. Step 3: improve water system and water quality in the park, combined with the development of

roof gardens/green roofs are crucial. Two water plazas will be developed in the near future: Bloemhofplein and

an amphibian residential habitat in the park. Steps 2 and 3 have been incorporated into the water plan as

Plein Riederbuurt-Noord. Both plazas can be realised in the short term.

research projects.

G r o e n h a g e n / Tu i n h o v e n ( W S H D 5 . 1 ) Following the refurbishment of the centre of IJsselmonde

and Groenhagen/Tuinhoven, compensating water must be created. The plan includes space for extra water, which will help to improve the water structure in IJsselmonde.

C r e at i o n o f e x t r a w at e r i n P e n d r e c h t a n d Zu i dw i j k ( W S H D 8 . 4 a n d 8 . 6 ) Due to the

restructuring activities, compensatory measures will have to be taken in the shape of extra open water. In earlier consultations, it was agreed to take these measures along the Reef. Where possible, space for water will be sought within the restructuring activities; however, this is supplementary to compensation. As a consequence of the research study “Improving the quality of the canal structure in the southern part of Zuidwijk”, part of the basic water requirements can be achieved for Keijenburg and Burgen-Zuidzijde during ongoing restructuring projects.

W at e r p r o j e c t s L o mb a r d i j e n ( W S H D 1 1 . 1 a n d 1 1 . 3 a n d W S H D 1 2 . 1 t o 1 2 . 4 ) These

projects involve various projects for creating extra water when the outside space is being restructured and refurnished. The main developments are the Station district, the canals and the refurbishment of Spinozapark. The construction of the new canals will create a better water system in the municipal district, which will also help to achieve better water quality.

M CRZ - R i j n m o n d - Zu i d M e d i c a l C e n t r e ( W S H D 1 3 . 1 ) Extra water will be created while the

industrial zone is being refurbished and the outside space around the new Rijnmond-Zuid Medical Centre (MCRZ) is being developed.

H o r d i j k e r v e l d ( W S H D 1 4 . 1 ) The refurbishment of the public space is an important part of the

restructuring of Hordijkerveld. Because of a shortage of water surface, the sub-standard infiltration of green

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‘A more extreme climate, great!’

An interview in the Westerpaviljoen? “Preferably not,” says the hugely popular RTV Rijnmond weatherman, Ed Aldus. “Everyone will be staring at me.” He decides instead on the deserted company restaurant as the place to share his vision on the weather and climate. “I’m in favour of tackling it globally. No offence, but when it comes to global warming, then the Netherlands is far too small to have any serious impact.”

A man and his hobbyhorse – a good description of the relationship between Ed

Aldus and the weather. Although any weatherman worth his salt is always going

to have something to say about his favourite subject, he seems to be ready to fire

off like never before. His first striking fact is already out: “Do you know something?

Everyone thinks that it rains a lot here. But it’s nowhere near that bad. It rains for

just seven per cent of the time.” Since his adolescence, in the early 1980s, when he

became fascinated by meteorology (“I was having discussions with the KNMI (Dutch meteorological institute) when I was fifteen”), he has not noticed any dramatic

increase in rainfall. “The only thing I have seen rise tremendously in recent years is the average temperature. Records have been tumbling, one after the other. “

“To give you an idea of what I mean – the present winter is comparable to the spring of 1962, so you can see how fast things are moving! Over the whole of the twentieth century, the temperature has risen by 0.9 degrees, and for this century predictions are for an increase of between 2.5 and 6.5 degrees. That’s quite a big difference...”

In spite of these impressive figures, Aldus’ view on the developments remains a downto-earth one, typical of the inhabitants of Rotterdam. “Hmmm, it’ll all happen after my time. So many scenarios are possible, one of which is that the earth will indeed

heat up, but that the Netherlands will actually get colder because of the influence of

the greenhouse effect and a change in the pattern of ocean currents. There are people who can substantiate this futuristic view with scientific calculations. But who is to

say it will actually happen?” As a weatherman, Aldus enjoys sudden downpours, while a weather warning adds an element of excitement to his day. “You will not get any

complaints from me about the fact that we are gradually moving from a temperate maritime climate to a more extreme one. On the contrary: I relish differences!”

Although the statistics and the graphs are endlessly flexible and can be interpreted

in many ways, Aldus is now certain that the earth is heating up, but he is not the type to suddenly start changing his car. “Not at all, where’s the point in that? Influencing the climate is a task for the whole world. But that’s not going to happen. Just think of China – it is just starting to prosper. They are not going to start throwing the

freezers away that they have just bought.” At best, he is susceptible to the idea of

environmentally friendly fuel purchases with a Greencard, where the CO2 emissions of 40 litres of petrol are compensated by a tree being planted (“it’s an easy way of

contributing”). Aldus regards the weather primarily as an unpredictable animal, one

that will always remain so. “Do you know what I would like? To be still around to see the first palm trees in Katwijk or Noordwijk.”

<streamer> “

A more extreme climate, great! ” 150

ED A L DU S A ND H I S DU T C H P A L M T R EE S 151

6.3 Research projec ts

In addition to projects that are due to be implemented in the coming period, there are a number of issues that first have to be worked out in detail. These research projects can have both a traditional and an innovative character.

G r e e n r o o f s ( H H D 7 . 4 , H H D 8 . 8 , H H S K 4 . 6 , W S H D 2 , W S H D 1 2 . 3 ) Research locations for

constructing and designing green roofs.

W at e r p l a z a s ( S pa n g e n , Oud e W e s t e n , Oud - Zu i d ) Research locations for constructing and

designing water plazas (both deep and shallow water plazas).

M u n i c i pa l d i s t r i c t w at e r p l a n H o e k v a n H o l l a n d ( H H D . 1 t o H H D . 5 ) For the local

implementation of measures in Hoek van Holland, in December 2005 the municipality and the District Water Control Board of Delfland started formulating its own policy and implementation programme. In 2006, a water system analysis was conducted to identify the bottlenecks. One important aspect of the water system is the interaction between surface water and wastewater and therefore the consequences for the basic water requirements. Based on the results of the water system analysis and the outcome of consultations with experts and interested parties, a strategy is being developed for the water in the municipality, after which the Hoek van Holland municipal district water plan will be drawn up in the course of 2007. The basic water requirements in Hoek van Holland will be worked out in detail in the municipal district water plan.

W at e r P l a n f o r t h e i n dus t r i a l z o n e s o f S pa a n s e P o l d e r a n d N o o r d - W e s t ( H H D 7 . 3

a n d H H D 8 . 7 ) The industrial zones of Spaanse Polder and Noord-West are not part of a Rotterdam

F i sh m i g r at i o n R e c h t e r M a a s o e v e r ( r i g h t - h a n d b a n k o f t h e M e us e ) The engineering works

municipal district. For these industrial zones, a joint water plan will be drawn up during the coming

located along Nieuwe Waterweg and Nieuwe Maas form a physical barrier between the outer waters and

planning period. For Spaanse Polder, the plan will link up with the restructuring that will take place in this

the drainage water. These engineering works do not include fish migration facilities, which means that

industrial zone in the years to come. The plan will focus on the possibility of storing and/or infiltrating

no migration takes place anywhere on the northern side of Rotterdam between the outer waters and the

water and on the sub-standard water quality due to the impact of wastewater overflows, maintenance of

drainage water. In the water plan, further research will be carried out into the possibility of realising at

the watercourses, the exchange between surface water and wastewater, and disconnecting the hard surface.

least one fish migration facility on the north side of the Nieuwe Maas/Nieuwe Waterweg. The following are

Because there are no opportunities during the 2007-2012 planning period to increase the amount of water

some of the reasons for this detailed research study:

storage in the form of surface water in the Oost-Abtspolder, opportunities will be sought to realise the remainder of the basic water requirements before 2015. An important point of focus when constructing new surface water in the industrial zone of Spaanse Polder is the location of the drainage embankment along Thurledeweg. During the implementation period of the water plan, it will be studied whether the drainage

- the Aal National Management Plan is applicable here; according to the Benelux Decree for fish migration, the water managers must make relevant waters passable for fish; - the professional fishermen in the region say that there is indeed a supply of migrating fish (unlike the report from OVB);

embankment must be relocated.

- the Rijkswaterstaat South-Holland Directorate is aiming to restore the possibilities of migration

S u r f a c e w at e r a l o n g H o r v at hw e g ( H H D . 9 . 1 . ) Along Horvathweg in the Oud-Mathenesse

between State waters and adjacent drainage and polder waters.

polder, there is a possibility to realise extra surface water and in that way replace part of the long culverts in the area. To do this, approximately 3,000 m3 of water will be realised. In addition, surface water

N e w su r f a c e w at e r O v e r s c h i e ( H H S K 1 ) Overschie currently has basic water requirements

along Horvathweg will have a positive effect on the water quality because it will considerably increase the

of 37,000 m3 increasing to 50,000 m3 in 2050. The requirements are mainly determined by a number of

throughflow.

low-lying homes with steel foundations. The research study will focus both on calculating the requirement in detail and on the possibilities of constructing new canals in the Kleinpolder and Blankenburgersingel.

S u r f a c e w at e r S pa a n s e B o c h t ( H H D . 9 . 3 . ) The Haven railway line along Spaanse Bocht will

disappear in the long term. This will make it possible to increase the existing surface water, disconnect the

N e w c a n a l s Oud e N o o r d e n ( H H S K 2 ) The Oude Noorden has very extensive basic water

hard surface in the district of Spangen and improve the water quality.

requirements. The aim of this research study is to find suitable locations for new canals that can also link Oude Noorden with Blijdorp.

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N e w c a n a l s C r o o sw i j k ( H H S K 3 ) In Crooswijk, there would seem to be a good possibility of

resolving the basic water requirements by constructing new canals. A number of locations are interesting from an urban planning perspective and are being researched in more detail.

N e w c a n a l s C e n t r um ( H H S K 4 ) Research study into the possibility of a new canal in the area

of Henegouwerlaan, ‘s-Gravendijkwal.

W at e r s y s t e m K r a l i n g s e z o o m ( H H S K 5 ) Development of a good water system compatible

with the development of the Kralingsezoom.

R e s e a r c h s t ud y w at e r p l a z a s Oud - Zu i d ( W S H D 2 ) A research study will be launched into

the possibility of constructing deep and shallow water plazas close to Afrikaanderplein, among other locations.

Pa r k D e t w e e h e u v e l s ( W S H D 4 . 1 ) Research study into the possibility of drawing the clean

water from the drainage basin further into IJsselmonde (more water) and increasing and improving its use (residential /recreational purposes).

P e n d r e c h t a n d Zu i dw i j k ( W S H D 8 1 , 8 . 2 , 8 . 3 , 8 . 7 , 8 . 1 1 ) Water park and new water-based

residential habitats around the harbour railway line. In cooperation with the Nieuwe Unie, options must be researched for the construction of more water.

L i n k b e s i d e F i l o s o f e n buu r t ( W S H D 9 . 1 ) Here it is necessary to research the extent to which

the quality of Zuiderpark can be extended through to Lombardijen.

Ex t r a w at e r H o r d i j k - O o s t i n dus t r i a l z o n e ( W S H D 1 3 . 2 ) In addition to the water close to

the new MCRZ to be developed, it is important to look for more space for water. This can be done during the refurbishment of the industrial zone.

R e i j e r s o o r d ( W S H D 1 4 . 2 ) In this area, extra space for water must be sought when designing the

outside space.

W e n d e l d i j k ( W S H D 1 4 . 3 ) During the follow-up to the development around Hordijkersingel,

M a i n f l o o d d e f e n c e V i e r - a n d M e r w e h a v e n ( G . 1 ) Research study into the safe and

sustainable strengthening of the main Vier- en and Merwehaven flood defence that ‘causes no barriers’.

the following will be looked into: possible extra space for water, the possibility of linking as little hard surface as possible to the wastewater collection system, and realisation of a good link between the new

F l o o d d e f e n c e i n r e l at i o n t o e xpa n s i o n o u t s i d e t h e d y k e s ( G . 2 )

Hordijkersingel to be constructed and the existing water along the Zevenbergse dyke. These will be

Research study into flood defences in relation to new expansion locations outside the dykes.

examined in combination with residential living in an environment rich in water.

F i sh s t o c k s m a n a g e m e n t p l a n ( G . 3 ) The formulation of a fish stock management plan that

P e r n i s ( W S H D 1 7 . 2 a n d 1 7 . 3 ) The centre of Pernis has basic water requirements that can only

covers the whole area, partly in the context of the Water Framework Directive (KRW).

be realised in combination with refurbishment of the centre. In this densely-built part of Pernis, the water quality in the existing canals is very bad as a result of wastewater overflows and limited throughflow.

C o mmu n i c at i o n p l a n ( C o m . 1 ) The formulation of a communication plan, including a

Options must be sought to link the existing canals to each other.

communication calendar.

F l o o d b r o c hu r e ( C o m . 2 ) The development of a flooding and safety brochure for all

P e r n i ss e r pa r k / R i n g / S t r i e n dw a a l s e w e g ( W S H D 1 8 . 2 a n d 1 8 . 3 ) In this area, options will

have to be sought to create extra water, possibly in combination with the new layout of the sports park.

Rotterdam residents.

L i n k i n g t h e Zu i d e r pa r k - K o e d o o d z o n e ( W S H D 1 a n d 2 . 2 4 , 2 . 3 a n d 2 . 2 1 ) By going along

C o mmu n i c at i o n m at e r i a l s ( C o m . 3 ) The development of presentation and informative materials.

with plans in progress and constructing connecting watercourses, it may be possible to convey clean water from the Koedood in the direction of Zuiderpark. The route is currently being researched. This project is expected to be implemented quickly once the research study has been completed.

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Acknowledgement

Waterplan 2 Rotterdam was drawn up under the authority of the Municipality of Rotterdam, the Schieland and

Krimpenerwaard Water Control Board, The Hollandse Delta Water Authority and the Delfland Water Control Board. steering committee: Michael Sliedrecht (vz), Arnoud Molenaar, John Jacobs, Arie van der Vlies, Johan Helmer, Govard Slooters, Marco van de Esschert, Bert Vos, Jos Kuijpers.

project office and editing: John Jacobs (projectmanager), Pieter de Greef, Caroline Bosscher, Bernou Haasnoot, Erna Wever, Jan Peter Speelman, Marleen de Jong.

supervision and research: Jaap Spaans (Witteveen + Bos), Lodewijk van Nieuwenhuijze (H+N+S landschapsarchitecten), Ingenieursbureau Gemeentewerken Rotterdam 2e druk - september 2007 people who contributed to waterplan 2: Arie van Asperen, Nick van Barneveld, Eelco Bavelaar, Elijan Bes, Jelmer Biesma, Marcel van Blijswijk, Hans Boeijen, Hans van der Boor, Caroline Bosscher, Jannekee Brand, Jorien Burger, Rian van Daalen, Teije Dalstra, Marco van de Esschert, Rens Fransen, Corjan Gebraad, Liliane Geerling, Gerjon Gelling, Monique Godijn, DaniĂŤl Goedbloed, Pieter de Greef, Bernou Haasnoot, Helen Hangelbroek, Jack Hemelraad, Thecla den Hoed, Kees van der Horst, John Jacobs, Sascha Jenke, Marleen de Jong, Eunice de Jonge-Berg, Saskia Jouwersma, Marije ten Kate, Alex de Klerk, Joke Klumper, Erica Koning, Fred Kuipers, Joost Lankester, Siebe Lans, Erik Leemreijze, Michiel Lips, Mirabel Loos, Hanneke Maandag, Astrid Madsen, Arie Markus, Harrie Meesters, Marit Meier, Erwin Meijboom, Arnoud Molenaar, Jan-Willem Mulder, Bas Nanninga, Marije Neggers, Margreet Nijeboer, Arjan Offerhaus, Kees van Oorschot, Marc den Ouden, Jan Overweel, Wynand Paling, Stiene Pilon, Nathalie de Rechter, Alex Retel, Niels Robbemont, Hetta Schultz, Ester Segers, Sandra Sijbers, Maren Slijkhuis, Klaas Sloots, Jan Peter Speelman, Rob Taffijn, Wim Twisk, Maaike Veer, Margreet Vermeer, Ad Vermeulen, Mark Verschuur, Kors van Vliet, Wim van der Vliet, Erna Wever, Rob van der Wolf, Csaba Zsiros, Bert van Zutven. people responsible for the boxes: Box I Inspiratiebronnen: Jaap Spaans, Pieter de Greef / Box II Risicobenadering: Joost Lankester, Arie Markus, Marije ten Kate / Box III Waterkwaliteitsbeelden: Marit Meijer, Wim Twisk, DaniĂŤl Malschaert (illustraties) / Box IV Waterpleinen: Florian Boer (VHP), Marco Vermeulen (Urban Affairs) / Box V Groene daken: Liliane Geerling / Box VI De Rotte: Erica Koning / Box VII Waterfonds: Caroline Bosscher, Roland van der Heijden design: Yvo Zijlstra, Antenna-Men, Rotterdam / photography: Eric Fecken, Jan van der Meijde, Peter van Es, Jannes Linders, Roel Tervoort (pag. 6) / interviews: Hans van Willigenburg / summary: Rieneke Enzlin / print:: Thieme Mediacentre Rotterdam / production: Gemeente Rotterdam, augustus 2007 / more information: www.waterplan.rotterdam.nl 160