Vén Duna - side arm reopening
Vén Duna - side arm reopening
Key features of the case study
Site description
The Vén-Duna sidearm is a water body located in the Gemenc floodplain, a nature reserve on the Danube river. The sidearm was largely blocked off by an artificial rock dam. This dam isolated the Vén-Duna sidearm during low and average flow conditions. It was build to improve navigation on the Danube. During high water levels in the Danube main channel the rock dam allowed water to flow into the sidearm through a small opening. This led to exceptionally high flow speeds near the dam. The flow speed decreased further downstream, but a well defined through-flow was still apparent. An up-filling of the side arm took place at the same time. The sidearm was characterized by periods of extremely bad water quality, caused by the hydrological isolation. Also, the flora and fauna were changing from rheophilic species towards stagnant water species. The forest surrounding the arm has undergone significant changes in the last decades due to an increase in logging and forestry industrial pressure. The hardwood oak (Quercus forests have largely been replaced by artificial plantations of Populus trees, a fast growing softwood species.
Measures selection
Success criteria
Ecological response
Hydromorphological response
Monitoring before and after implementation of the project
Socio-economic aspects
Contact person within the organization
Extra background information
References
Related Measures
- Remove or modify in-channel hydraulic structures
- Reconnect backwaters and wetlands
- Improve backwaters
