River dynamics as ecosystem services for the implementation of the EU WFD

In natural watercourses, naturally occurring self-dynamic changes in water morphology are a constant process that influences the structural quality. In anthropogenically influenced sections, these processes are often not tolerated or are reversed through the implementation of maintenance measures. In the Guldenbach case study presented here, high discharges resulted in the relocation of the river and further structural improvements. The unleashing of the watercourse created new structures with an improved width and depth variance. The higher structural quality and thus the creation of natural or near-natural conditions were favoured. With the massive relocation of bottom substrate, possible chemical loads in the river bed were flushed out, which may have contributed to a reduction of the material load. The creation of new and high-quality habitat structures has led to an enhancement of the entire aquatic species community. New retention areas were also created. Further positive effects on the impact on other communities of terrestrial and semi-terrestrial species can be expected from a more regular recurrent flooding of the floodplain forest. The evidence from this case study reveals how the dynamics of the water body could be valued as a free ecosystem service for the implementation of the EU water framework directive (WFD).

Automated summary

High discharges in anthropogenically influenced watercourses can lead to river relocation and structural improvements, creating new high-quality habitat structures that enhance the entire aquatic species community.