Indicator: Ecological status of rivers

A graph shows the distribution of the environmental status and potential of the rivers for the years 2010 and 2015. The target for 2027 is also shown (100 percent ‘good’ or ‘very good’). In 2015, 6.7 percent showed at least a good status or good potential.Click to enlarge
Percentage of running waters in at least good status or with at least a good potential
Source: German Environment Agency / German Federal Institute of Hydrology Figure as PDF

Table of Contents

 

At a glance

  • In 2015 only around 7 % of German streams and rivers were in at least a good ecological status or had at least a good ecological potential.
  • According to the European Water Framework Directive, by 2015 all rivers should have achieved at least a good ecological status or potential.
  • This target has not been achieved. The time up to 2027 must be used to reach these demanding objectives.
  • The measures taken to date require more time to take effect. Other measures are also required.
 

Environmental importance

Streams and rivers are an important part of the environment. The character of landscapes away from the coasts is provided primarily by rivers. Their status had deteriorated seriously in the past. Due to water engineering works over the last few centuries, around half of all streams and rivers are now considerably modified or artificial. Rivers are also polluted by contaminants and nutrients from industry, private households and agriculture.

Water pollution causes changes in the original species composition. The indicator primarily reflects the degree to which the current species composition in the rivers corresponds to the original composition. The closer the species diversity to the original status, the better the ecological status and therefore the more resilient the ecosystem. The ecological potential, on the other hand, is specified in significantly modified or artificial water bodies, because a comparison with the natural species composition is not possible in such cases.

 

Assessing the development

The proportion of streams and rivers in at least good ecological status or with at least good ecological potential remained almost constant between 2010 and 2015. This proportion was just under 7 % when last measured. The most important reason for this is that species communities which have been disturbed on the long term require time to recover. This was initially underestimated. However, the proportion of running waters in a bad or poor status declined between 2010 and 2015. At the same time the proportion of running waters in a moderate ecological status increased significantly.

The European Water Framework Directive (WFD, EU Directive 2000/60/EC) was agreed in 2000. This set a target for all water bodies in Europe of a good or very good status by 2015. The Federal States drew up management plans defining measures for improving water quality. Germany was not the only country that missed the 2015 target for most streams and rivers by a large margin. The two subsequent management cycles under the WFD now need to be used to reach the ambitious targets by 2027 at the latest.

 

Methodology

The ecological status of a stream or a river is primarily defined on the basis of the presence of different species and their abundances. This is compared with the species composition which would naturally be present in this type of water body. Five status classes are defined, depending on the degree of divergence, from ‘very good’ to ‘bad’. An ecological potential is assessed for artificial and heavily modified water bodies. The highest potential is present when all measures to improve the environmental quality have been taken which do not have a significant negative effect on use. The classification is laid down in the Surface Waters Ordinance (cf. water protection policy in Germany).

More detailed information: 'Ökologischer Zustand der Fließgewässer' (in German only).