Water + Nature

Room for the River IJssel Delta

The construction of the Reevediep, a new river arm (or bypass) in the IJsseldelta near Kampen, is one of the largest Room for the River projects. The Reevediep is constructed to channel water, during high water levels, via the Drontermeer and the Vossemeer toward the IJsselmeer. H+N+S Landscape architects has been involved in this project since 2014: until 2014 the plans were executed by the Province of Overijssel and the project partners and as of 2014 by Isala Delta, the consortium.

© Hans van der Meer

Motive

Background room for the river

Large projects are being executed in 34 locations in the Dutch river area. The rivers have to cope with more and more water, which increases the risk of flooding. In order to prevent this, dikes are relocated, flood plains are dug, high water channels and even bypasses are constructed, which is a considerable challenge. Besides safety, the Room for the River programme has another objective: spatial quality. Therefore, landscape architects are involved from the concept phase through to the construction phase.

In ‘String of beads' scenario, measures are particularly identified around cities, combined with urban development.

In the initial phase of the Room for the River project, H+N+S developed a number of future secenarios for the Dutch rivers. Each scenario is linked to a specific set of measures to solve the water management task. In the ‘Broadened river ribbon’ scenario, measures are evenly distributed along the river, especially within the existing winterbed. In the ‘Old and new rivers’ scenario the current river area transforms into a much more natural region with natural bypasses. In the ‘String of beads’ scenario measures are particularly identified around cities, combined with urban (re)development. Specifically along the IJssel river and the point where the river splits, this scenario seemed applicable.

Approach

Along the IJssel river an inlet is built in order to allow the water to pass through the high water channel. The Kamperstraatweg will cross this inlet. Dikes will be built to the north and south of the high water channel. Between the provinces of Flevoland and Overijssel a dam will be constructed in the southern part of the Drontermeer to prevent high water from flooding into the Drontermeer. The dam will be equipped with storm surge barriers which will only be closed in extreme conditions. At Nieuwendijk, a bridge of about 400 metres long will be built over the Reevediep.

Result

Dynamic nature in the delta

The hundreds of acres of high quality and dynamic nature that are added to the south of Kampen are a substantial stimulus to the city’s character and image. The narrow river arm in the east will broaden to the west and, surrounded by wetlands, will seamlessly merge into the Drontermeer. The water level will fluctuate widely in the future due to the effect of the wind: the character of the delta will be fully expressed.

Experiencing nature and water

There are numerous possibilities to experience this new natural landscape. Along the dikes cycle tracks are constructed which run for miles. And a sailing connection through the Reevediep represents a major improvement for the connection of the peripheral lakes to the north.

Two phase realisation

The Reevediep will be constructed in two phases. Firstly, as of 2017 the high water channel will be deployed to a limited extent, in addition to deepening the summer bed of the Beneden-IJssel (another subproject of Room for the River IJsseldelta). Water recreation in the Reevediep is possible by the end of 2017. In 2025 the second phase will be finished.