Room for the River: Nijmegen dike relocation, Netherlands
Year of issue
2025
Summary
This flagship of the national Room for the River programme at Nijmegen set back the dyke at Lent and excavated the Spiegelwaal side channel, creating the Veur-Lent island and an urban river park that can take additional flood flow from the Waal. Completed in 2016, the scheme achieves about 35 cm lower design water levels—exceeding the original 27 cm target—and safely diverts high flows; the channel first overtopped its threshold in February 2016. Since delivery, the area has been reshaped as public space with new bridges and intense recreational use. In 2022 the city decided not to build housing on Veur-Lent, keeping the island largely as parkland (with limited facilities), while planning proceeds nearby. The Spiegelwaal now serves as a pilot in “Connected River” to balance flood safety, water quality and heavy leisure demand; bathing advice has at times been negative due to bacteriological risks. Funding came mainly from the State, with total costs reported at about €351 million.
Photo Gallery
Location
51.856, 5.862
Project
NWRM
National ID
Netherlands_01
Sector
Hydromorphology
Installation Date
2013-2016
Implementation status
Completed
Contact
Heather Williams and Dilian Jansen, AMEC
Overview
Location of the project
Near the town of Nijmegen, in eastern Netherlands
Country
Netherlands
NUTS2 Code
Gelderland
Sponge measures implemented in the case study
Floodplain restoration and management
Removal of dams and other longitudinal barriers
Objectives
Lower design high-water level by ~27 cm at Nijmegen for Q=16,000 m³/s; move the northern dike ~350 m inland; create an ancillary channel/urban river park. Result exceeded target with ~35 cm reduction post-completion (2016).
Involved partners
| Authority type | Authority name | Authority role | Comments | Authority responsibility |
|---|---|---|---|---|
| National water authority | Rijkswaterstaat | Financing | Financing | Responsible |
| Other | Gemeente Nijmegen | Implementation | Direct overall project responsibility | Responsible |
| National water authority | Ministerie van Infrastructuur en Milieu | — | Involved directly in planning and execution of infrastructural changes | Responsible |
| Architects / Engineers | Staatsbosbeheer | Determination of design details of the measure | Involved in the planning and development of recreational and nature aspects on the future island | Supporting |
Documents
Document
cs-nl-01-final_version.pdf
(944.18 KB)
Site Information
Climate Zone
Cool temperate moist
Temperature (°C)
10.80 °C
Elevation range
13 m
Slope range
0-1%
Vegetation class
Mosaic of riparian grasslands, reed and tall-herb fringes, and softwood riparian forests (“ooibos”), consistent with Natura 2000 “Rijntakken” targets; grazed floodplain nature nearby (Gelderse Poort/Stadswaard).
WFD Ecological status
Poor
WFD Chemical status
Failing to achieve good
Water quality status
Bathing water frequently constrained by bacteria and episodic cyanobacteria; urban/recreation pressures in a busy side channel.
Design and Implementation
Project scale
Meso
Project scale specifications
Creates an entire new district of the city
Project area
70
Project area specifications
The 70 hectares only applies to the area where the dike will be moved back 350 meters.
Principles
The main principles were increasing water safety (reduced risk of flooding) within an integrative planning framework. The measures are incorporated with an area of urban development that will provide aesthetic and recreational benefits, together with an enhancement of the spatial quality in the area.
Factor constraints
The main factor that influenced the choice for this measure was the possibility to combine it with a larger city redevelopment project. The creation of a district on the other shore of the Waal, together with a revitalization of the shore at the old city center made the creation of this river park that will be in the center of the city in the future possible.
Constraints
This type of measure is suitable for rivers with permanent flow where the capacity to flow out-of-bank is currently restricted. There are no specific basin characteristics that are necessary, as the measures could be applied in a range of situations.
Favourable preconditions
The availability of open space in between the current river bank and the town. The sharp meander in the river provided a suitable geometry for addition of this type of measure
Financing
Total cost
351000000.00 €
Costs investment
351000000.00 €
Costs investment information
Cost of the entire project, including the water retention mesures.
Compensations
Yes
Compensations annual information
Compensation is required to owners and occupiers of the land that will be used for the measures, who will be displaced.
Policy and Governance
Policy description
Addressing the risk of flooding from the River Waal, particularly following flooding events in 1993 and 1995. This is part of a national programme of work by the national government to make 'Room for the River'.
Land ownership
Spiegelwaal water/bed: State (Rijkswaterstaat). Bridges: City of Nijmegen. Most grounds on the city island (Veur-Lent): City. Stadswaard floodplain east of town: largely Staatsbosbeheer.
Policy targets
Peak-flow reduction
Increase Water Storage
Oher Societal Benefits
Target remarks
The water retention measure is being combined with a city development project.
Policy pressure
| Directive | Relevant pressure |
|---|---|
| WFD identified pressure | Physical alteration of channel/bed/riparia n area/shore of water body for flood protection |
| Floods Directive identified pressure | Blockage / Restriction |
Pressure remarks
Currently a bottleneck exists in the sharp bend of the river, which will be remedied moving back the dyke and the digging of a parallel channel inside the reconnected floodplain.
Policy impact
| Directive | Relevant impact |
|---|---|
| WFD identified pressure | Altered habitats due to hydrological changes |
| Floods Directive identified pressure | Rural land use |
Impact remarks
Rural area in the area between the current dike and the town of Lent will be affected as the channel will be dug here and the area will be completely reformed, leaving no room for previous uses.
Requirement directive
| Requirement directive | Specification |
|---|---|
| WFD-mitigation of significant pressure | Bottleneck at a location with high population density will be solved |
| WFD-achievement of good ecological status | On the new island there will be room for nature development |
| Floods Directive-mitigating Flood Risk | The measure will significantly reduce the flood risk |
Policy challenges requirements
The Planologisch kernbesluit (PKB) Ruimte voor de Rivieren forms the overall impetus for this NWRM. The PKB identifies roles and responsibilities for 30 individual NWRM related projects to reduce flood risk of the entire river system.
Part of a wider plan
Yes
Wider plan
| Wider plan type | Wider plan focus | Name | Comments |
|---|---|---|---|
| National | Water | Room for the River programme | National strategy to create more space for flooding, rather than raising dykes further, initiated following widespread flooding in 1993 and 1995 |
| National | Water | FloodResilienCity (FRC) | INTERREG IVB programme enabling public authorities in eight cities in North West Europe to better cope with urban flooding. Nijmegen is one of the eight cities |
Public consultation
Yes
Consultation activities
| Comments |
|---|
| Extensive public communication for the national programme as a whole, as well as locally for this specific measure |
Has contractual arrangements
No
Impacts and Monitoring
Impact Assessment Methodology
Performance impact assessment method
Laboratory
Performance impact estimation information
Monitoring is carried out of river flows in the Waal. The measure has been modelled prior to implementation, consistently with all schemes in the Room for the River programme: this has allowed the performance of the whole Room for the River programme to be assessed, not only this individual scheme.
Socio-economic Impacts
Direct benefits information
Flood risk reduction in the lower Waal
Ancillary benefits information
Amenities and social benefits relating to housing provision, recreation, greening cities : Creation of new permanent aquatic habitat. Urban development with a strong blue-green connection.
Biophysical impacts: Hydrology
Information on retained water
Reduced extreme water levels by ≈35 cm; during high flows ~⅓ of discharge is routed via the Spiegelwaal; overtopping threshold provides controlled activation; creation of a new island and low-flow habitats altered local hydromorphology.
Information on peak flow reduction
The measure provides a 35 cm reduction in design flood peak height on the River Waal.
Information on increased groundwater level
Groundwater levels can already be high in this area, causing groundwater seepage. It was a specific aim of the project to ensure that groundwater seepage did not increase.
Information on Restoring hydraulic connection
Hydraulic connection between the river and part of its floodplain is being restored by moving the dyke backwards by 350m, and developing a new channel within the floodplain that will always contain water and will provide additional flood capacity.
Information on peak delay effects
In addition to reducing peak height, the measure is also likely to delay the peak, although no quantification was available
Biophysical impacts: Biodiversity
Improved biodiversity
Yes
Information on improved biodiversity
Provision of increased aquatic and riparian habitat along the edges of the new channel
Biophysical impacts: Water & Soil Quality
Water quality overall improvements
Not relevant for this application
Soil quality overall improvements
Not relevant for this application
Biophysical impacts: Others
Ecosystem impact climate regulation
No specific impact
Lessons Learned
Key lessons
The ability to have an influence at a large scale, particularly in the lower reaches of a major river basin, requires commitment at high levels of government. This is the case with the Room for the River programme.
The integration of this particular scheme in to a wider programme with an overall goal ensures that individual measures do not adversely affect flood vulnerability in down- or upstream locations or in other river basins, and that the combination of individual measures leads to a cumulative, quantifiable positive effect on flood risk.
The integration of this particular scheme in to a wider programme with an overall goal ensures that individual measures do not adversely affect flood vulnerability in down- or upstream locations or in other river basins, and that the combination of individual measures leads to a cumulative, quantifiable positive effect on flood risk.
Drivers
| Driver type | Driver role | Comments |
|---|---|---|
| Past flooding events | Main driver | Flooding events in 1993 and 1995 led to the development of the national Room for the River programme |
| Organisation committed to it | Main driver | The national government decided on this approach and has led and funded its implementation |
Success factors
| Success factor type | Success factor role |
|---|---|
| Attitude of decision makers | Main factor |
| Financing possibilities | Main factor |
Cost effectiveness
A traditional approach may have been to increase the flood defenses of the existing channel of the Waal.
Flexibility / Adaptability
The current NWRM did not only aim to meet current peak water levels historically measured, but the Ruimte voor de Rivieren program as a whole aims to be able to handle an increased flow rate to 16,000 m3/s (from 15,000 m3/s) (across the main distributaries of the Rhine); this in anticipation of future more extreme weather circumstances caused by climate change.
Transferability
The measure here is being applied to a large river near the bottom of a very large transboundary river basin. However similar measures could also be applied on a smaller scale.
In a water retention measure being combined with a city redevelopment project, it is important that there is an actual demographic/public demand to attract future private investment in the newly developed housing area and recreational activities.
In a water retention measure being combined with a city redevelopment project, it is important that there is an actual demographic/public demand to attract future private investment in the newly developed housing area and recreational activities.
Basin characteristics influence
This type of measure is suitable for rivers with permanent flow where the capacity to flow out-of-bank is currently restricted. There are no specific basin characteristics that are necessary, as the measures could be applied in a range of situations.
Sources
Sources