The vision that we developed for the Berkel river between Borculo and Lochem aims at an improvement in quality with opportunities for nature and agriculture. In consultation with the Rijn en IJssel Water Board, farmers and local organisations, we examined how we could restore structural variation to this stretch of the river.
Location
De Berkel tussen Borculo en Lochem
Principal
Waterschap Rijn en IJssel
Design Year
2019 - 2020
Implementation
2020-
We decided to make the water channel shallower to reduce the cross-section of the profile. To give the Berkel a more natural embedding, with vegetation inside the embankments, the latter have to be moved, creating an opportunity for the side channels to follow a more natural course.
The Rijn en IJssel Water Board is working on the task of improving the water quality, flora and fauna in and beside the Berkel. A missing link at the moment is the stretch between Borculo and Lochem. The Water Board asked us to develop a vision for the Berkel between Borculo and Lochem and the surroundings in close consultation with the Water Board, farmers, and local organisations.
The greatest challenge facing the Berkel is to restore structural variation with alternating deep and shallow water, natural river banks, and thereby variation in current. To achieve this target, in this vision we decided to make the Berkel shallower to reduce the cross-section of the profile. To accommodate the river better in the landscape, with vegetation inside the embankments, the embankments have to be moved. We tried to follow the natural elevations of the landscape as much as possible in moving the embankments, or if they are high enough, to use these elevations as a natural barrier. Since the embankments have to be moved, the side channels that are currently in the zone and provide drainage must be adapted too. This creates an opportunity to allow the side channels to follow a more natural course and at the same time to give the farmers more land beside the river.
The redesign of the Berkel is also an opportunity to make the river banks more nature-friendly. It becomes interesting to promote tall vegetation on the southwestern bank in particular, with room for the occasional tree. This affords shade and cooling for the Berkel, which is both ecologically and recreationally interesting. The plots of land continue to run down to the river. The banks of the side channels come under single management, enabling more landscape variation in the capillaries of the landscape too. In addition, there are recreational opportunities concentrated mainly around Borculo and Lochem. The area in between is only designated for extensive recreation.