Implementation

Implementation

Barrage IV – Altusried

Measures:

  • First gravel depot at the river bank
  • Later, plain gravel area (ideally constructed with a long-arm excavator)
  • Adding some larger rocks to improve flow diversity

Stability:

  • Uncontrolled distribution of the gravel depot/area at flood events
  • Large rocks in the river bank provide stabilization

Ecology:

  • With the uncontrolled distribution of gravel from the gravel depot, habitats only develop by chance.
  • A targeted input of gravel in the river provides more control over the creation of habitats.
  • Using a long-arm excavator helps avoid disturbances in the river.

Barrage VI – Legau

Measures:

  • Covered sole: Only where suitable habitats can develop, gravel is distributed over a disperse layer of large rocks.
  • The density and size of the rocks necessary to stabilize the gravel can be adapted to the site-specific flow velocities.

Stability:

  • The rocks significantly improve the stability of the gravel bank.
  • Only small amounts of gravel are washed downstream.

Ecology:

  • Habitats suitable as spawning habitats can be created.
  • In addition, the rocks improve flow diversity in the river.

Barrage VII – Maria Steinbach

Measures:

  • Creation of groynes for a higher flow diversity and to activate erosion at the opposite river bank

Stability:

  • There were no damages at the groynes, even after larger flood events.

Ecology:

  • High flow diversity
  • Partly critical colmation between the groynes
  • Activation of erosion at the opposite river bank was not
    successful.

Nature-like fish passes

Measures:

  • Construction of diverse nature-like river structures in the fish passes, also at existing facilities

Stability:

  • High stability as there is no impact from flood events.

Ecology:

  • It is possible to create key habitats in nature-like fish passes for many species.
  • However, it is also necessary to maintain these structures, for example to avoid colmation.