Session E3: Upstream Migration

Abstract: Until 2013, almost 500 barrage weirs were made passable for fish by building fish ladders and by even removing the barriers. The most commonly used types are the pool-weir and the vertical slot passages. A special measure has to be taken at the main ‘front door’ of the Rhine and Meuse rivers, the Haringvliet, that currently is shut from the sea by a dam that only allows downstream migration. In 2018 the dam will be partly opened, in order to make upstream migration possible. In the Upper Rhine, five barrages still have to be provided with fish passages in order to meet the Rhine objective of ‘passability’ to Basel in 2020. The fish passage at the Strasbourg impoundment will start operating in 2015. The same year, construction work on the fish passage at the Gerstheim impoundment will start in order to reconnect the Elz-Dreisam area with the Rhine. The experience and assessment of the effectiveness of the fish passages in the river system built so far will contribute to improve the technical solutions still to construct. The transfer of fish into the old bed of the Rhine in the region around the impoundment Vogelgrün/Breisach is a technical challenge. An efficient fish pass system at the impoundments Rhinau, Marckolsheim and Vogelgrün on the Upper Rhine still must be planned and implemented. Another issue regarding upstream migration is posed by fishing along the river, both by anglers and professional fisherman