• Fish habitats were improved over a total length of 3 km of river sections and 1,2 km of fish passes.
  • Fish populations of many endangered species such as the Danube salmon increased (e.g. up to 200% of more juvenile individuals).
  • Typical riverbank vegetation was successfully developed in 3 locations over a total length of 830 m.
  • The situation for macrozoobenthic species has improved, providing better food supply for fish.
  • The overall demand for gravel has been significantly reduced, the negative effects of gravel pits eliminated.

Social aspects:

  • The project is a win-win situation for all parties involved. All stakeholders supported the approach.
  • Increased river accessibility and quality of the river for recreational activities at 3 locations
  • Increased fish population makes the river Iller more attractive for fishing.

Technology and economy:

  • The minimal-invasive bedload management was successfully implemented at a total length of 3 km of river sections and 1,2 km of fish passes.
  • The measures supported the implementation of the “good ecological potential” of the river Iller.
  • Using a minimal-invasive approach, implementation and maintenance costs were significantly lower than those of other measures requiring large volumes of gravel.
  • Bedload management measures are only promising if stream current is sufficient.


  • CO2 emissions for production, transport and implementation of material (gravek, rocks etc.) were reduced.
  • The resilience of the eco system has been improved.

Bavarian Environmental Protection Award

ISOBEL was part of the “Iller Strategy”, a long-term project to improve river ecology and flood protection that involved a unique cooperation of local and regional stakeholders. In 2018, the bedload management approach of ISOBEL was awarded the Bavarian Environmental Protection Award (“Bayerische Umweltpreis”) by Bayerische Landesstiftung, the Environmental Foundation of the State of Bavaria.

Experience ISOBEL in real life

You can visit the beautiful valley of the river Iller and enjoy hiking and cycling along the river, visiting the three project sites in Maria Steinbach, Legau and Altusried. The attractive official bike route “Illerradweg” passes the project sites as well as the bike route “Nature and technology in the iller region”.

ISOBEL has been presented at 4 national and 6 international conferences and will be presented at more conferences and events in the future. Check out the “News” section of this page to find out more.