Project IJsseldelta, in: International Journal of River Management (2011)

1. Modern Integrated River Flood Management for Climate Change in
the Netherlands: the IJssel Delta Project
MARIUS SOKOLEWICZ, DHV B.V., P.O. Box 1132, 3800 BC Amersfoort, the
Netherlands
Email: Marius.Sokolewicz@dhv.com
TEUNIS LOUTERS, DHV B.V., P.O. Box 1132, 3800 BC Amersfoort, the
Netherlands
Email: Teunis.Louters@dhv.com
ARJAN OTTEN, Province of Overijssel, P.O. Box 10078, 8000 GB Zwolle, the
Netherlands
Email: A.Otten@overijssel.nl
Abstract
This paper describes a planning process combining river flood management with
spatial planning. Within the IJssel Delta project, a river bypass in the river IJssel, one
of the major Dutch rivers, is planned to reduce the risk of flooding in view of
expected climate change effects. The challenge for this project was to combine
various developments (bypass, urban development, nature, leisure, infrastructure and
agriculture) in the area into a single integrated spatial development plan, acceptable to
all stakeholders. This included resolving spatial conflicts between separate
developments regarding (i) flood protection, (ii) infrastructure and (iii) housing.
During the planning process various bypass alternatives were considered to determine
the span width of possible solutions. Various technical issues related to the bypass
design have been studied using state-of-the-art methods. A participatory approach
involving public and private stakeholders has been used to secure a widely accepted
development plan. The plan has been adopted by the responsible authorities. It is now
in the final planning stage and is scheduled for execution from 2013 onwards.
Keywords: integrated river flood management, flood protection, spatial planning,
participatory approach, collaborative approach, climate adaptation
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2. 1. Introduction
1.1 Modern Integrated River Flood Management
This article describes the implementation of modern integrated river flood
management in the IJssel Delta project in the Netherlands. Here, a participatory and
collaborative approach involving all relevant stakeholders has been applied. This was
combined with advanced technologies (hydraulic, morphological, geohydrological
modelling and probabilistic methods), and legal and economic assessments to pursue
an integrated spatial development plan. The main goal of this collaborative approach
was to achieve a sustainable development plan for the future, widely supported by the
stakeholders. Within this plan, a bypass will be constructed to adapt the river to the
expected climate change without constraining the urban and infrastructure
development in the area. The participatory approach, defined as “involving all
relevant stakeholders already in early stages of the planning process to achieve wide
support to the resulting spatial development plan” is the basis of the modern spatial
planning and river flood management in the Netherlands (Healey 1997), (VROM
2010).
Earlier stages of the planning process in the IJssel Delta project were published
between 2005 and 2009 in (Louters et al. 2005), (Hoeven et al. 2007) and (Otten
2009).
1.2 Project Background
The river IJssel in the Netherlands is a major branch of the river Rhine, the 3rd
largest river of Europe. It discharges into lake IJssel, which is a former sea
(Zuiderzee), closed off in 1932. The IJssel Delta (Figure 1) is a low-lying area that is
threatened by floods from both the river IJssel and from the lake IJssel. It is protected
from flooding by dikes with a high safety standard. The IJssel Delta is mainly an
agricultural area, with the city of Kampen (50,000 inhabitants) in its centre.
Several major spatial development schemes have been planned for the IJssel Delta
for the coming decades. Kampen plans to expand considerably and build 4,000
houses; a new railway line (the “Hanze” line) is under construction, and two highways
(N50 and N23) crossing the area will be reconstructed. Furthermore, as one of
measures of the national “Room for the River” programme (V&W 2006) aiming at
increasing safety against flooding along the river Rhine branches, construction of a
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3. bypass diverting a part of flow from the river IJssel during extreme flood conditions is
also planned in this area. All these separate, potentially conflicting spatial
developments are dealt with by the IJssel Delta project which aims at achieving a
single integrated spatial development plan (Hidding and Vlist 2009), acceptable to all
stakeholders.
Figure 1: Location of the IJssel Delta in the Netherlands
1.3 Partners and stakeholders
In 2004 the Province of Overijssel initiated the process of making a sustainable
development plan for the IJssel Delta area. The Province has played a coordinating
role in the planning process (Brink 2009). The development plan has been prepared in
close cooperation with other stakeholders: ministries, municipalities, neighbouring
provinces, water boards and many non-governmental organisations in the region. The
Municipality of Kampen, the Water Board Groot Salland and the Province of
Flevoland have been the most important partners. The national Government also
committed itself to this project and selected the IJssel Delta project as a pilot project
for modern integrated river flood management using the collaborative and
participatory approach principle with a strong focus on spatial planning (VROM
2010). The national ministries still involved are the Ministry of Infrastructure and
Environment, and the Ministry of Economic Affairs, Agriculture and Innovation.
Furthermore, the public (a.o. local farmers and inhabitants of Kampen) has been
actively involved in the plan-making process.
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4. 2. River flood management as a trigger for creating a river bypass
2.1 Safety standards in flood protection
The required safety standards for flood protection in the Netherlands are
imposed by law. These safety standards are expressed in terms of water level
exceedance probability and are related to the design river discharge and to the
corresponding design water levels. The dikes are required to withstand these water
levels (TAW 1998), (Anon 2009).
The river IJssel is a downstream river branch of the river Rhine in the
Netherlands. The design river discharge for the Rhine and its branches has an
exceedance probability of 1/1,250 per year. The IJssel Delta area forms a transition
zone between the lake IJssel and the river IJssel. Due to its location the area is
exposed to floods from the river IJssel and to storm-induced floods from the lake
IJssel. Therefore the safety standard of the area is set at 1/2,000 per year, with a
corresponding design discharge of 2,550 m³/s. The maximum damage caused by
flooding of the IJssel Delta is estimated at € 2 billion (Brinke et al. 2008), (Vermeulen
and Leenders 2009).
2.2 Climate change
In 1993 and 1995 extremely high river levels occurred in the Netherlands, creating
a nearly-catastrophic situation. More than 100,000 people along the Rhine branches
had to be evacuated. New research on the statistics of river discharges caused the
design discharge in the river Rhine to be increased from 15,000 m3/s to 16,000 m3/s
(V&W 2006). For the downstream stretch of the river IJssel (a Rhine branch), this
caused an increase of the design water levels with 0.10 to 0.50 meters (Sokolewicz
and Hoeven 2005), (V&W 2006). The existing dikes are not designed for these higher
water levels, therefore short-term measures are necessary to keep the safety against
flooding at the level required by the law.
Considering the expected climate change as projected by IPCC (2007), an increase
of the design discharge of the Rhine to 18,000 m3/s and a sea level rise of 0.60 meter
in 2100 are taken into account in the national policy in the Netherlands (V&W 2006).
This would cause the design water levels in the downstream stretch of the river IJssel
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5. to rise with 0.20 to 0.60 meters (V&W 2006). Therefore, the climate change has to be
considered in today’s plans for the long-term development.
2.3 Room for the River
The increased design discharge along the Dutch rivers requires measures to
maintain the required safety against flooding. Instead of building higher and stronger
dikes a new strategy has been chosen in the Netherlands: to increase the conveyance
of the river system by creating more space for the flow. This strategy - a real
‘paradigm shift’ in water management - has been adopted in the national Dutch
programme ‘Room for the River’ (V&W 2006). Instead of a foe - that should be
tamed and conquered - water is becoming more and more a friend for the planners and
water managers. There is growing awareness among them that water and flood
protection measures create opportunities for spatial development, such as nature,
recreation and housing.
The primary goal of the Room for the River programme is restoring the safety
against flooding to the level required by law without raising the dikes. This means that
the increased design discharge of 16,000 m³/s has to be conveyed through the river
system without exceeding the old (pre-2001) design water levels. The secondary goal
is improving the “spatial quality” along the rivers by increasing the diversity between
the Rhine branches, strengthening the open character of the riverine landscape, and
nature development in the floodplains (V&W 2006).
The program consists of a large number of measures in the river Rhine system
in the Netherlands: 40 measures for the short-term (Figure 2), to be completed by
2015, and several long-term measures, to cope with the projected climate change
(increase of extreme river discharge and sea level rise). One of the most important
long-term measures in the downstream reach of the river IJssel is the so-called bypass
Kampen. The total budget available for the 40 short-term measures amounts to € 2.3
billion.
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6. Figure 2: Overview of the short-term measures envisaged within the Room for
the River program
2.4 Bypass Kampen
Within the framework of the “Room for the River” programme, creating a bypass
south of Kampen, as one of the options to increase the conveyance of the river IJssel,
was considered to be a very promising and sustainable solution for flood management
in the delta of the river IJssel. A new river branch will be created, connecting the river
IJssel through the lake Dronten to the lake IJssel (see Figure 1).
Figure 3. IJssel Delta during high river stage
Constructing the bypass will add 350 hectares to the floodplains in the delta of the
river IJssel. This means breaking with the past, because for centuries space has been
6

7. taken away from the river. For example, in 1850 the floodplains of the big rivers in
the Netherlands had almost 3 times more space (Demon and Alberts 2005) compared
with the present situation.
In case of an extremely high discharge in the river IJssel 25% of the flow will be
diverted through the bypass to decrease the water level in the river IJssel below the
design level, and a significant decrease of water levels along more than 10 km of the
river will be achieved. Even when the design discharge in the river Rhine is increased
in the future from 16,000 to 18,000 m³/s as a result of the expected climate change,
the planned flood protection measures (especially the bypass) will keep the projected
water levels along this 10 km long downstream stretch of the river IJssel sufficiently
below design water levels to avoid large dike improvement works (Province Overijsel
2011). The project has therefore a large contribution to the climate adaptation of the
area.
3. Application of Modern Integrated Flood Management Approach
3.1 Developments and spatial conflicts
In the IJssel Delta project the combined opportunities for sustainable economic
development and for enhancing the spatial quality of the area have been explored
(Rooy 2009). In the coming decades, the inhabitants of the IJssel Delta area, south of
Kampen, will experience significant spatial changes in their surroundings. These
changes and the resulting spatial conflicts are shown in Figure 4 and described in
detail below.
Figure 4: Illustration of developments and potential spatial conflicts in the IJssel
Delta project
A. The river IJssel: For the safety of the IJssel Delta area, the discharge capacity
of the IJssel needs to be increased in the future. The expected increased design
7

8. discharge cannot be conveyed within the present river profile. Therefore a bypass is
needed, with a capacity of about 700 m3/s. The bypass will provide safety against
flooding during extreme events with a probability of exceedance <1/500 per year. In
combination with other measures, the bypass should solve both the short-term and
long-term safety problems due to climate change. The preferred location for this
bypass is south of Kampen.
B. The Hanze railway line: The first phase of construction of the Hanze line, a
railway line from Amsterdam to Kampen and Zwolle (Figure 5), started in 2006.
According to project planning, the railway line would be in operation in 2013. At the
start of the IJssel Delta project it became clear that only very minor changes in the
alignment and the level of the railway would be possible. Major changes of the
railway would lead to an – unacceptable – delay as the necessary review of the
railway design would take too long.
C. Expansion of Kampen: The municipality of Kampen has now 50,000
inhabitants and covers an area of 162 km2, of which 27 km2 consists of water.
Kampen is expected to expand considerably in the coming decades, with 4,000 houses
to be built in the next 20 years.
D. Spatial conflict: The above-described developments are to a certain extent
conflicting, as they all claim parts of the same area. The combination and
concentration of the spatial challenges in the south-western part of the IJssel Delta
will contribute to the preservation of the north-eastern part of the delta, which is an
area with high cultural landscape values (National Heritage). Though some of the
developments are expected to take place on a longer term, extra synergy can be
obtained between the developments by early master planning at this time.
8

9. Figure 5: Hanze railway line under construction and N50 highway in the IJssel
Delta
3.2 Collaborative and adaptive process
Preparation of an integrated spatial development plan as in the case of the IJssel
Delta requires normally a long-lasting process involving many stakeholders. To obtain
sufficiently wide support for the plan, often many iterations in the planning process
are required. In the IJssel Delta project, being a pilot of modern river flood
management, a collaborative and participatory approach to the planning process (Kort
2009) has been adopted. All relevant stakeholders (inhabitants and more than 20
governmental and non-governmental organisations) have been involved already in
early stages of the planning process, and their concerns and requirements have been
thoroughly considered. This resulted in a relatively smooth plan development process
with only a minimum resistance to the plans, and in shortening the time span for the
planning and decision-making procedures. The planning process involved a
participatory approach with many interactions between designers, experts and
stakeholders, coordinated by the Province of Overijssel (Grijzen 2010). This process,
started in 2004, comprised a number of distinct steps:
Step 1: Exploration of possible bypass alternatives (2004). The relevant and
technically feasible routes of the bypass south of Kampen were studied, and the
solutions that would fulfil the project requirements were elaborated. This resulted in
five conceptual alternatives, spanning the range of possible solutions.
9

10. Step 2: Public participation and consultation (2005). Inhabitants, entrepreneurs
and other stakeholders were invited to give their input for the alternatives (Figure 5).
An additional (6th) bypass alternative was developed by the public and included in
further assessment and optimization. This alternative became an essential building
block for the preferred alternative and the Master plan (step 3 and 4).
Figure 6: Public consultations
Step 3: Decision making by the responsible authorities (2005). After public
consultations, the responsible authorities, i.e. the involved municipalities, provinces,
water boards and national ministries, have made their choice for a preferred
alternative.
Step 4: Further development of the preferred alternative (2005-2006). The
preferred scenario was elaborated in more detail in advanced studies, and reviewed on
technical, environmental, financial and legal feasibility. The most promising solutions
were selected. This involved regular feedback with administrators and representative
stakeholders.
Step 5: Adoption of the Master plan (2006). The Master plan was widely supported
by the public, as it was based on the 6th alternative of the bypass that was proposed by
the public (mostly farmers, assisted by planners and professionals).
Step 6: Signing of the Covenant (2007). A binding agreement between the 11
major stakeholders was signed in January 2007, with a commitment to work together
towards implementation of the Master plan. Another 11 non-governmental
organizations supported the plan.
10

11. Step 7: Review of the regional and local land use plan (2008-2011), together with
a Strategic Environmental (impact) Assessment (SEA) and an Environmental Impact
Assessment (EIA). In these impact assessments several design alternatives for the
plan were studied, including a so-called most environmentally friendly alternative.
This procedure has led to some adaptations of the Master plan. The current plan
(Figure 7) resembles in almost every aspect the most environmentally friendly
alternative of the SEA.
Step 8: Financial agreement and change of the scope of the IJssel Delta project
(2009). In 2009 an agreement was reached to finance the project. The most important
contributors to finance the total project’s cost of about € 325 million are the National
Government and the Province of Overijssel. Part of the financial agreement
constitutes a change in the scope of the project: the IJssel Delta project will be
implemented in two phases and will be combined with another adjacent “Room for
the River”-project: the deepening of the river IJssel over a length of 22 kilometers.
Combining the two projects enables a € 30 million cost reduction, as the sediment
dredged from the river can be used to construct the embankments of the river bypass
as well as a mound (as part of a “climate proof dike”) for housing development. One
of the most important reasons to modify the scope of the project was a recent change
in policy of the National Government (see par. 4).
Step 9: Preparation of the Detailed Design and Tender Documents. Recently, in-
depth studies (a.o. hydraulic, morphological, geotechnical, environmental
assessments) have been completed. With the results of these studies, detailed designs
for the plan are being made. Tender documents are being prepared parallel to the
detailed design. An Engineering and Construct contract is foreseen in order to provide
space for the Contractor for further optimisation. Studies, detailed design and tender
documents are to be completed in 2011.
Step 10: Final decisions and agreements (2011-2012). In the coming period
several extra administrative decisions and agreements have to be obtained (e.g. land
use plan, project agreement, implementation agreement, many licenses and permits).
The preparations for the decisions and agreements have already started.
Step 11: Implementation. After obtaining the final decisions and agreements, the
project will be implemented in two phases:
Phase 1: Construction of the physical part of the spatial development plan
consisting of dikes along the bypass, new nature areas, sailing channel and locks for
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12. small boats. The dredged sediments from the IJssel will be used to construct the dikes
along the bypass. The bypass will not be connected to the river system yet. The
implementation of Phase 1 is scheduled for the period 2013 - 2015.
Phase 2: Construction of the inlet and outlet structures. Once these structures are
in place, the bypass can be connected to the river and to the lake IJssel by opening the
weirs during floods. The start of the implementation of Phase 2 is scheduled in 2021.
Figure 7: Impression of IJssel Delta project
4. Coping with changing policy
The water level of the lake IJssel is controlled by large tidal flush gates
discharging to the North Sea. According to the present government policy, the lake’s
level will not fully follow the sea level rise, and only a minor water level rise of 0.23
meter in 100 years is foreseen in the coming century. This assumption was used as a
starting point when drafting the IJssel Delta project.
In 2007 the Government of the Netherlands requested an independent Committee
of State (the Delta Committee) to advise on flood protection in view of climate
change impacts in the Netherlands for the coming century (Delta Committee 2008).
Two main Committee’s recommendations are of major importance for the IJssel
Delta. The first one underlines the necessity to implement the long term “Room for
the River” measures – such as the river bypass – as soon as possible. The second one
is to gradually increase the level of the lake IJssel with a maximum of 1.5 meter in the
long term to cope with the increasing sea level and to provide a sufficient buffer of
12

13. fresh water. These recommendations are expected to be incorporated in the
Government’s policy, although it is not clear when and to what extent this will be the
case. A large increase of the water level in the lake will affect the IJssel Delta and the
bypass. To cope with the possible change in the policy, a flexible approach is
followed in the design of the projected dikes: they are designed to the current (less
stringent) policy requirements, but the design includes sufficient flexibility to be able
to raise the dikes in the future. A part of the new dike will be constructed as a climate-
proof dike – a kind of unbreakable super dike – that can serve as an embankment for
housing development. As a no-regret measure, this climate-proof dike and all concrete
structures are designed for the future (higher) water levels in the lake IJssel. As the
implementation of the large inlet and outlet structures in Phase 2 is postponed till
2021, it will be possible to adapt their design to the decision of the National
Government about the increase of the water level in the lake IJssel that is expected to
be taken in 2015.
5. Lessons learnt
1. The regional government (as a director of the plan-making process) has a crucial
role to raise awareness for climate change and to gain public support for climate
adaptation measures in the area. In the case of project IJssel Delta an intensive,
bottom-up process of public participation has resulted in a new optional draft for
the bypass (a 6th alternative) that was made by the public;
2. To make sure that climate adaptation measures are taken seriously and are being
implemented, a combination and integration with spatial planning and
development is recommended (“think beyond the water box”). An illustrative
example of this integrated approach is the combination of five spatial challenges –
housing, infrastructure, nature development, leisure, agriculture – with a river
bypass in the IJssel Delta project;
3. Thinking beyond the water box requires that new coalitions have to be made
(cooperation with other policy fields and levels, private investors and project
developers). This requires a reflexive, collaborative style of planning in which
communication between the stakeholders and joint fact finding are key elements
(Healey 1997);
13

14. 4. For this collaborative style of planning (which requires skills of facilitation,
advocacy, networking and negotiation), also strong and visionary leadership are
essential competences for the project leader and the responsible political
representatives (for instance in cases of impasses between the stakeholders);
5. The combination of water management with spatial planning has a potential to
generate additional sources to finance climate adaptation measures. Several
governmental bodies contribute to finance the IJssel Delta plan.
6. Conclusion
Creating a bypass to give the river more conveyance has been demonstrated to be
a very promising solution to flood hazards in the project area. While reducing flood
risks, it also creates opportunities to enhance the environmental quality. Climate-
proofing is a critical factor being taken into consideration in the project. The
challenge for the coming decades is to harmonize future spatial planning with flood
protection and creating “room for the river”.
The planning process followed in the IJssel Delta project required large flexibility
to adequately respond to the changing policies, climate change projections, interaction
with other projects. The project organisation was able to successfully introduce
necessary changes to the plans, make no-regret decisions, introduce phasing in the
implementation program, achieve large cost-reduction by combining two
neighbouring projects, and secure additional funding sources through integration
between sectoral activities.
The participatory and collaborative approach to spatial planning as applied in the
IJssel Delta project, with the support of a multidisciplinary expert team has proven to
be a successful practice in modern river flood management (Hajer et al. 2010). The
Dutch Government has selected the IJssel Delta project as a “best practice” (VROM
2010).
Acknowledgments
The authors wish to express their gratitude for the valuable comments and
contributions from Joost ter Hoeven, Guoping Zhang, Frank Dekker, Yvonne van
Kruchten and Jan Oomen.
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15. References
Anonymous, 2009. Water Act (in Dutch).
Available from:
www.waterwet.nl
Brink, M. van de, 2009. Rijkswaterstaat on the Horns of a Dilemma. Dissertation.
Radboud University, Nijmegen, the Netherlands.
Brinke, W.B.M. ten, Bannink, B.A., and Ligtvoet, W., 2008. The evaluation of flood
risk policy in The Netherlands. Journal of Water Management, Volume 161, pp. 181-
188.
Delta Committee, 2008. Advice to the Dutch Cabinet.
Available from:
http://www.deltacommissie.com/en/advies
Demon, A., and Alberts, F., 2005. Lange termijn visie Ruimte voor de Rivier (in
Dutch). Rijksinstituut voor Integraal Zoetwaterbeheer en Afvalwaterzuivering.
Grijzen, J., 2010. Outsourcing Planning. What do Consultants do in Regional Spatial
Planning in the Netherlands. Dissertation. University of Amsterdam.
Hajer, M., Grijzen, J., and Klooster, S. van ‘t, 2010. Strong Stories: How the Dutch
are reinventing Spatial Planning. Design and Politics #3. Rotterdam: Uitgeverij 010.
Healey, P., 1997. Collaborative Planning. Shaping Places in Fragmented Societies,
2nd ed. Hampshire, England and New York, NY: Palgrave MacMillian.
Hidding, M., and Vlist, M. van der, 2009. Ruimte en Water: Planningsperspectieven
voor de Nederlandse Delta (in Dutch). The Hague, the Netherlands.
Hoeven J. ten, Louters, T., Sokolewicz, M.J., and Otten, A., 2007. Future of the
IJsseldelta: an example of Contemporary River Basin Management and Adaptation to
Climate Change. In: Proceedings of the 31st Annual Conference of Association of
State Floodplain Managers, June 2007, Norfolk, Virginia, USA.
IPCC, 2007. Contribution of Working Groups I, II and III to the Fourth Assessment
Report of the Intergovernmental Panel on Climate Change; Core Writing Team,
Pachauri, R.K. and Reisinger, A. (Eds.), IPCC, Geneva, Switzerland.
Kort, A.T. de, 2009. Designing a Strategic Plan Development Approach for
Integrated Area Development Projects. Dissertation. University of Twente, Enschede,
15

16. the Netherlands.
Louters, T., Pierey , J., Ellen, T. van, and Otten, A., 2005. Future of the IJsseldelta:
an example of Modern River Basin Management. In: Proceedings of the 2nd
International Yellow River Forum, October 2005, Zhengzhou Shi: Yellow River
Conservancy Press.
Otten, A. 2009. Climate adaptation in the IJsseldelta. In: Proceedings of the 5th
World Water Forum, March 2009, Istanbul, Turkey.
Province Overijssel, 2011. IJsseldelta Zuid, bypass Kampen, Hydraulica en Veiligheid
(in Dutch).
Rooy, P. van, 2009. Nederland Boven Water: Praktijkboek Gebiedsontwikkeling (in
Dutch). Habiforum/NIROV/VROM, Gouda/The Hague, the Netherlands.
Sokolewicz, M.J., and Hoeven, J. ter, 2005. Hydraulische beschouwing bypass (in
Dutch), DHV.
Available from:
http://www.ijsseldeltazuid.nl/bibliotheek/technische/
TAW, 1998. Fundamentals on Water Defences. Technical Advisory Committee on
Water Defences. Delft, the Netherlands.
V&W, 2006. Spatial Planning Key Decision “Room for the River”. Ministry of
Transport, Public Works and Water Management, the Netherlands.
Available from:
www.ruimtevoorderivier.nl
Vermeulen, C.J.M., and Leenders, J.K., 2009. Veiligheidsaspecten van de bypass
Kampen (in Dutch), HKV.
VROM, 2004. National Spatial Strategy (in Dutch). Ministry of Housing, Spatial
Planning and the Environment, The Hague, the Netherlands.
Available from:
http://notaruimteonline.vrom.nl/0206010000.html
VROM, 2010. Nederland verandert!: 23 Gebiedsopgaven van Nationale Betekenis (in
Dutch). Ministry of Housing, Spatial Planning and the Environment, The Hague, the
Netherlands.
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