New findings on low water of the Rhine

Solothurn, 3 and 4 July 2018

During the first half of the last century periods of low water on the Rhine were distinctly more pronounced. Discharges were lower, and low flow periods lasted longer than in the past 50 years. The perception that low water occurs more often than in the past is not correct. However, water users are more affected, e.g. navigation, energy production, industry and agriculture.

This is the surprising result of the statistical analysis of historical discharge series carried out within the activities of the International Commission for the Protection of the Rhine (ICPR) and discussed in this year’s Plenary Assembly of the Commission in Solothurn (Switzerland). These findings may predominantly be attributed to the regulating influence of numerous reservoir lakes in the Alpine region. Also, the trend towards increasing annual precipitation observed in the Rhine catchment during the 2nd half of the 20th century may contribute to this fact (see Fact Sheet: Annex 1). However, since low flows directly impact water quality, ecology and uses, they will in future be monitored.

Since the beginning of the “Salmon 2000” programme and the “Master Plan Migratory Fish Rhine” adopted in 2009, numerous measures aimed at improving river continuity and improved habitats have been implemented. The ICPR has now updated the Master Plan. Removing obstacles to migration of fish and other water organisms is still a focal point of the Master Plan (see Fact Sheet: Annex 2).

Two events expected for the autumn 2018 will considerably improve the situation for migratory fish in the Rhine system: On September 5, 2018 the Haringvlietdam in the estuary near Rotterdam will be partly opened and function as a migration route even at high tide. From the autumn 2018 on, river continuity of a further section of the main stream of the Rhine will be restored, as the new fish pass at the Gerstheim barrage - following that opened at Strasbourg in 2016 - will be inaugurated. With this new fish pass migratory fish will again be able to migrate into the Elz-Dreisam area (near Freiburg/D). Accessibility to this area must still be improved, work on sills and the loops will carry on.  

The ICPR Project Group on restoring ecological river continuity in the Upper Rhine (PG ORS) has achieved important progress in its discussions. Experts have exchanged much technical and fish-ecological know-how. Two possible solutions for fishways for upstream fish movement have now been developed for the Vogelgrün impoundment. Also, the optimal position of entrances and required attraction flow has been identified for fishways for upstream migration at Rhinau, Marckolsheim and Vogelgrün, so that the detailed planning of these facilities can continue.

On the occasion of the ICPR Plenary Assembly Mr. Kurt Fluri, member of the National Council and Mr. Roland Fürst, mayor of Solothurn and senior civil servant, head of the Department of Construction and Justice of the Canton Solothurn referred to the almost total lack of natural waters in the intensively used Swiss Midlands. However, brooks, rivers and lakes form the blue ribbon of ecological infrastructure required to enhance and maintain species diversity on the long term.

Furthermore, the representatives of the states in the Rhine catchment addressed the preparation of a new programme “Rhine 2040” setting the course for the future.


Further information

International Commission for the Protection of the Rhine (ICPR)


Short information

As Rhine bordering countries, Switzerland, France, Germany and the Netherlands as well as Luxemburg and the European Community co-operate within the International Commission for the Protection of the Rhine (ICPR) on the basis of a treaty under international law. The President (at the time being Mrs. Martine Rohn-Brossard from Switzerland) and the different ICPR fora are supported by the international staff of the permanent secretariat in Koblenz (Germany). Furthermore, the secretariat gives support to the countries in the Rhine watershed when implementing the European Water Framework Directive (Directive 2000/60/EC) and the European Directive on the Assessment and Management of Flood Risks (Directive 2007/60/EC). To this end, cross-border co-operation was extended to Austria, Liechtenstein, Italy and the Belgian region Wallonia. The working languages of the ICPR are German, French and Dutch. For detailed information on the ICPR please browse to the ICPR website: