Technical planning and construction
The water supply of Old-Drava is improved by water retention artefacts in the ox-bow and water supply channel from river Drava. Bottom weirs are key factors to improve water level within Old-Drava by retention of water coming from Rinya creek. By these structures the average water level will be improved approximately with 1 metre, which positively affects the oxbow and its surrounded habitats. The bottom weir will be periodically passable by fish and will not block the longitudinal connectivity of the oxbow, and the connectivity between the oxbow and the main stream of the river.
Improving of water level is a key factor to improve ecological status of the project area. Without water retention the project would not be able to improve the status of riparian forests. Beside water retention the water supply of the oxbow will also be improved. The supply channel from river Drava will drive water into the oxbow with gravity. The technical design will define what water level of Drava can feed the oxbow with freshwater. The water supply from Drava is another crucial important point of the project. This extra water can help to reduce the risk of very low waters in the oxbow, which can generate quick eutrophisation, especially if the low water period is during summer.