Decreasing water levels in the River Old Drava have lowered water levels in a transborder oxbow lake in a Natura 2000 network site. Due to riverbed erosion, only high floods in the river can fill up the oxbow, but the frequency of these floods is very low. There are certain periods of low precipitation, for instance, that negatively affect ecological conditions; neither the Old Drava nor the Rinya stream that feeds into it can drive enough water into the oxbow. Decreased water level, along with abandoned angling infrastructure, endangers aquatic habitats and species listed in the Habitats Directive. Action is therefore required to modify the water regime in the Danube-Drava National Park.
The main objective of the LIFE Old-Drava project is to contribute to the conservation and resilience of riparian habitats by improving the water regime, thereby preserving and enhancing biodiversity in and around an oxbow lake. Specific project actions are to: Raise the water level by constructing one or two bottom weirs, which will increase the average water level of the oxbow by 0.5-1.0 m, and to construct a new channel between the riverbed of the Drava and the upper section of the Old Drava rivers; Restore habitat through discharge enhancement of the oxbow, and the stabilisation of sufficient water level with water retention structures that reduce the risk to species arising from low water periods; Harmonise human and nature conservation activities through campaigns, for example, targeting local anglers and requesting them to remove abandoned angling platforms and other litter from the oxbow; Contribute to improving transboundary nature conservation into the future; and Raise public awareness by various types of communicational tools.
Expected results: As a result of improving water discharge, the average water level increased by 0.5-1.0 m; Increased water table positively affects about 176 ha of gallery forest, along with the oxbow lake, with all aquatic habitats in better condition and extremely low water level not endangering Natura 2000 fish and bird species; Abandoned angling platforms (around 30 of 117 total) removed, along with waste from the oxbow and gallery forest; Guidelines published in three languages, including recommendations for cross-border administrative criteria and requirements; and Around 15 000 people informed about the project, with local inhabitants’ knowledge about the floodplain’s natural value improved, to help manage and use the Natura 2000 site in a more nature-friendly manner.