Rijkelse Bemden - River bed widening
Rijkelse Bemden - River bed widening
Key features of the case study
Site description
The area of Rijkelse Bemden is situated along the river Meuse and is an area that historically consisted of two river terraces. The area was predominantly used as grassland with a low-intensity agricultural purpose. Parts of the area were used for as an orchard. Around 1950 the Meuse was straightened and canalized in this region. As a result a number of gravel bars and small islands which were previously present in the channel and floodplain area disappeared. The banks of the river were also fixated. From 1965 to 1985 the area was used as a source of sand and gravel and was mined intensively. This led to a lake forming in the area which filled up with water. The banks of the lake have been used from 1985 onward as low-intensive agricultural land.
Measures selection
In 1996 the area was designated as an area for nature development and work was started on the spit between the river channel and the lake. The bank area was added to the area and a number of islands of differing sizes were made along the banks of the lake. Also a few pools were dug. All of this was done to create a greater diversity in available habitats and thus increase biotic diversity. Between 1998 and 2001 the Meuse was widened for the Project Zandmaas, a project striving to restore some of the natural characteristics of the Meuse while improving the flood protection for the nearby inhabited areas. This was also done near the Rijkelse Bemden. The river was widened by 40 meters, giving it more room and thereby a higher capacity during peak discharges. The sediment material that became available from this exercise was used on the banks and in the lake of the Rijkelse Bemden, creating more natural banks and locally making the lake more shallow. The entrance to the lake was closed off by means of a buoy line to minimize disturbance in the lake by recreational activity.
Success criteria
No clear criteria were formulated for the area.
Ecological response
Hydromorphological response
Monitoring before and after implementation of the project
Socio-economic aspects
Ecosystem goods & services
Gravel, sand and clay mining (historical).
Synergies and conflicts
The project was carried out to increase the room for the river and thereby improve flood protection during high discharges. At the same time the clay and sand that was taken from the river bed widening was used in the banks of the Rijkelse Bemden. Locally it was also used to shallow the ponds in the area.
Costs
The total project of the river bed widening and restoration of the Rijkelse Bemden was estimated to cost 13 million euro.
Contact person within the organization
Extra background information
References
Related Measures
- Link flood reduction with ecological restoration
- Widen water courses
- Shallow water courses
- Allow/increase lateral channel migration or river mobility
- Recreate gravel bar and riffles
- Adjust land use to develop riparian vegetation
- Adjust land use to reduce nutrient, sediment input or shore erosion
- Lower river banks or floodplains to enlarge inundation and flooding
- Set back embankments, levees or dikes
- Retain floodwater
