Case study: Multi-functional flood defences, De Stadswerven and Westflank, Dordrecht

Location of the case study

De Stadswerven and Westflank, Dordrecht, NL

Description of the application

The De Stadswerven case study was a redevelopment project in a former shipyard area, located on the edge of the historical city centre of Dordrecht. It was proposed to develop 1600 residential buildings with an associated range of commercial, cultural and public facilities. The 30 ha development area was located in the outer flood plain which is not protected by the main ring dike for the City, being adjacent to the river confluence for three rivers: the Beneden–Merwede; Noord and Oude Maas; one of the most intensively used waterway areas in the world. Fluvial flood risk was initially not considered in the plans, but at the outset the requirement was stipulated to raise the ground level of all new developments in the area in accordance with the Dutch Water Act (2009) to ensure flood safety. The development process started in 2001 when the municipality acquired land and developed an urban masterplan for De Stadswerven that was eventually approved by the city council in April 2005. Following the concept of flood defence, the ground level was to be raised up to 4 m above mean sea level to meet regulations. In the following period the delivery of the De Stadswerven redevelopment was delayed and the approved masterplan was subject to further review due to a perceived lack of ambition and estimated cost overruns. This created tension between the private development consortium and the municipality and also political tension between the city council and government. Two local governors were questioned by the local parliament and the municipality faced a lawsuit against the private developers. The city government decided to suspend work on the project in September 2007. During the suspension of work on the project, there was a change of ownership in the private development consortium, now led by a new private developer. Meanwhile, the research project Urban Flood Management (UFM) Dordrecht (2005–2008) was created with a LAA comprising public, private and research partners. The De Stadswerven redevelopment was used as a case study for knowledge development for the LAA UFM, without initially directly engaging in the project; i.e. only as external observers. Nevertheless, after the project planning was temporarily suspended in 2007, the UFM LAA then had to directly support the delivery of the project. The UFM LAA challenged the requirement to raise the ground level of the entire area based on flood risk analysis suggesting a low vulnerability. Upon resumption, the masterplan was redefined which provided an opportunity, a ‘policy window’, to use an integrated flood risk management approach proposed by the UFM LAA. Flood risk was used as a design variable for the new masterplan. It included lower lying, attractive water-rich, yet flood proof areas as well as raised areas and infrastructure that can serve as safe havens and escape routes for evacuation. As a first step towards its implementation in practice, the UFM LAA proposed and actively participated in a feasibility study for a pilot FRM project to provide 100 flood proof dwellings in the De Stadswerven redevelopment. The second case illustrates the initiation and design phases of a development in the Westflank Haarlemmermeer area of The Netherlands. The area is situated in the Randstad and metropolis region of Amsterdam and is expected to provide some 20,000 new dwellings between 2010 and 2030. The planned development is to take into account a number of spatial constraints: spatial and environmental policies for Amsterdam Schiphol airport; spatial policy for the Greenport Bollenstreek area and water policy to increase local water detention and storage. The development comprises 3036 ha, with 10,000 new dwellings; 1 M m3 peak flood retention capacity; 2 M m3 seasonal flood water storage and some 900 ha of recreational green space. The LAA provided a new approach to effectively deliver on the water storage objectives that is now setting an example for profitable, attractive developments. This, in turn, is changing policy in The Netherlands in relation to such developments. From 2004 a spatial plan was developed for Haarlemmermeer Bollenstreek, adopted by regional parliaments and presented to the national ministry of Housing, Spatial planning and the Environment in May 2006. Within a year of the start of the spatial planning process for the proposed development, a broad consortium of public, private and research partners created an LAA as part of the research project ‘Building with Water’ (BwW). BwW (2004–2008) aimed to learn about flood resilient and climate proof urban development in polder areas – behind the dike rings – and had the explicit ambition from the outset to contribute to the overall planning of the Westflank development. The LAA BwW identified the Westflank as a possible location for water storage and housing, for which a spatial exploration was executed with support from BwW. This included conceptual designs of high density urban areas with water storage, supported by a technical feasibility study, a market study and a cost benefit analysis. In November 2007, after lobbying of the LAA BwW, the project was included in the national policy programme Urgency Programme Randstad, thus providing access to additional financial, legal and political support. In the following 2 years a development strategy was defined with water areas and multi-functional use of space as guiding design principles. As a first step towards its implementation in practice, BwW stakeholders agreed on the intention to deliver a pilot project ‘waterliving’ of 500 dwellings. This research has revealed that LAAs can support collaborative planning. The case studies in Stadswerven and Westflank provided relevant empirical evidence of social frameworks that supported the integration of flood risk management into urban planning processes. The two LAAs have had a decisive influence on the urban masterplans and related policy proposals that have been adopted. The LAA UFM proposed design concepts with varying ground levels and a new flood proof building typology. BwW proposed the combination of housing and green areas with water storage to exploit fluctuating water levels. The design concepts embraced multifunctional use of space through which flood risk management was connected with other objectives and interests. For both case studies, respondents highlighted a shift in perspective where flood risk management was seen as a solution instead of a problem.

lessons learned

Urban development, regeneration and retrofitting present windows of opportunity to reduce flood vulnerability that are often not taken advantage of. Collaborative planning is needed to integrate urban retrofitting and development processes and flood risk management. This can be achieved by a social learning framework: Learning and Action Alliance (LAA). The two case studies in The Netherlands show the value of LAAs that had a decisive influence on the flood proof, urban development masterplans and related policy proposals that have been adopted. LAAs can be a governance or coordination mechanism or policy instrument to create flood resilient urban areas by taking advantage of current redevelopment and retrofitting opportunities.

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Implementation costs (Show all)

>1.000.000 €


Served purpose of implementation (Show all)

Strongly Positive

Responsible authority levels (Show all)

Local

Projects (Show all)

PREPARED


Application types (Show all)

Real Case Study



Last modified: Sept. 12, 2016, 8:19 a.m.