In order to ensure safe water flow from the IJssel river, a new riverbranch has been designed in the IJsseldelta. The water will now flow on two sides along the city of Kampen to the IJsselmeer (IJssel lake). The new river called ‘Reevediep’ starts narrow on the IJssel and widens further downstream. This new Dutch delta landscape is the final piece of the Room for the River program. Flood safety leads to hundreds of hectares of perceptible delta nature, 17 kilometers of new dikes, locks, bridges and a water inlet. The main design principles are the very large scale, long lines, natural dynamics and the beauty of water works: engineering the landscape as artwork.
Due to climate change the maximum discharge of Dutch rivers increases. The aim of Room for the River is flood protection by providing extra space in order to prevent higher water levels. In the old city center of Kampen, the river bed of the IJssel is very narrow: a so-called ‘urban bottleneck’.
During extreme circumstances the Reevediep will drain water from the IJssel, to the IJsselmeer. H+N+S Landscape Architects have been involved in the project since 2004 commissioned by the Province of Overijssel, while from 2014, H+N+S was a team member of Isala Delta, the executive contractor combination. NEXT architects and Trafique were involved in the project since 2012. The project was officially opened in spring 2019.
The new river stretches along 6 kilometers, with an average width of 500 meters. The dikes of the Reevediep, of which 17 kilometers were newly constructed, have been designed with great attention: a 21st-century addition to the landscape. The project’s design includes a clear contrast between the northern and southern dikes. The northern dike is distinguished with an articulated profile which includes a heightened cycling path, offering an extensive view over the Reevediep itself and the wide cultural landscape. In contrast, the southern dike has a low-lying cycling path close to nature. The dike is shaped with curves along the IJssel side, while becoming stretched towards the IJsselmeer. All bends and connections are designed with the utmost precision, and so are the entrances and exits.
The humble design of the infrastructural elements reduces the use of materials while simultaneously providing dominant structures in the landscape. All constructions have been designed within one design style in order to create architectural coherence and unity along the Reevediep.
An additional component that received great design attention is the architectural expression of the hydraulic operation. The work on the inlet of the IJssel is arranged ingeniously; a summer dike now serves as a threshold while a subtle lowering of the fluvial ridge facilitates the inflow. The relocated IJsseldijk includes a bridge with sloping pillars that emphasize the stream direction. A small migration channel under the bridge along the Reevediep improves the water quality and ecological connectivity.
The shipping channel connects to the IJssel by a lock. Due to the construction of the navigation channel, the Reevediep is an important new link in the national tour network, and a boat tour along Kampen becomes a new attraction. The unique structure of the recreational sluice forms an accent on the IJsseldijk, while providing a recreational junction around the area where waterways, cycling and walking routes connect. The ‘Nieuwendijk bridge’ spans the entire flood room from dike to dike as the pillars stand as “slender legs” in the swamp landscape.
The design of the floodable landscape, apart from the water around the fairway, is largely based on the original elevation; the lower parts contain new reed swamps while the higher parts are accessible for natural grazing. Natural processes will have enough space to enrich, vary and broaden the delta landscape, while the patterns of the previous agricultural landscape will gradually fade away. On average, once every 5 years the water from the IJssel flows over the inlet threshold. Furthermore, due to the interventions along the existing reed bank of the Drontermeer, the old Zuiderzeedijk has been replaced and reed swamps have been added in order to encourage threatened bird species such as the bittern. At the mouth of the Reevediep a new village is planned.
The newly constructed Reevediep is a Dutch delta landscape where nature and culture go hand in hand – as if it has always been there.
Entrant office name: H+N+S Landscape Architects
Role of H+N+S in the project: Landscape Architect Role of NEXT architects: Design of the infrastructural elements
Other design firms involved in the design: NEXT architects, Trafique
Project location (State or Country): The Netherlands
Design year: 2004 -2012
Year Built: 2014 – 2019