The Dutch Rhine delta is now easily passable for migratory fish. In the Nederrijn-Lek estuary, there are three barrages equipped with fish ways. With the implementation of the 'Kier' project since November 15, 2018, the way for salmon migrating upstream from the North Sea into the rivers Meuse and Rhine is open again at the Haringvliet Dam (south of Rotterdam), given sufficient discharge. Depending on the water level, one or more gates are now open even at high tide. Much is also being done to ensure ecological continuity at the third arm of the IJssel estuary. At the closure embankment between the North Sea and Lake IJssel, there is a fish pass and a fish-friendly sluice management system. In addition, a kilometre-long fish migration river is being built there.
Between the German-Dutch border (Rhine km 700) and Iffezheim (south of Karlsruhe, Rhine km 334), the Rhine is free for fish to migrate.
There are numerous barrages in the Upper Rhine, between Iffezheim and Basel. The four barrages Iffezheim, Gambsheim, Strasbourg and Gerstheim have already been equipped with fish ways.
From 2015 to 2020, the ORS (Upper Rhine - Rhin supérieur) project group accompanied the implementation planning of an efficient fish pass system at the following Upper Rhine barrages Rhinau, Marckolsheim and Vogelgrün for the ICPR. In addition, minor passability or optimisation measures in the loops of the Upper Rhine were also addressed. In the meantime, the work of PG ORS has been completed. The results of the work were published in a technical report (cf. ICPR technical report No. 262, available in German, French and Dutch).
According to the new program "Rhine 2040", passability at the barrages Rhinau, Marckolsheim and Vogelgrün in the Upper Rhine as well as in the High Rhine up to the Rhine Falls shall be implemented in the next years.
For specific information on the status of fish passability of the tributaries on the Lower, Middle and Northern Upper Rhine, reference is made to the internationally coordinated river basin management plan 2022-2027 for the international river basin district Rhine, chapter 188.8.131.52 (see maps K7, K8, K30 and Annex 7).