Erosion TTool/Installation of fascines

Technical articles - Erosion TTool - Érosion des sols

Grandes cultures Grandes cultures Erosion TTool

Illustration of the practice of fascine installation within the serious game Erosion TTOOL. Credit: Delphine Hombrouckx

Fascines are structures made of intertwined branches assembled together to create a barrier.

Description

Advantages

• Reduction of runoff water velocity.
• Sedimentation of soil and filling of gullies.

Disadvantages

• Time for installation and cost (large quantities needed).
• Requires site preparation.

Tips

• Location:
  • At the foot of slopes >5%.
  • At the foot of slopes >2 or 3% if sensitive crops or along the slope direction.
  • In the bottom of a talweg with slope >1%.
  • At the parcel/area interface with stakes (watercourse, urban, road).

• The length of the fascine is at least equal to the width of the observed flows.

• It is recommended to place several fascines in cascade rather than a single row for better efficiency.

• Installation:
  • Recommended species: white willows or marsault willows.
  • Dig a trench to bury the first bundle.
  • Place stakes staggered or opposite.
  • The rest of the bundles are installed between the two rows of stakes 50cm to 1 m above the upstream ground, and fixed with battens.

• Maintenance:
  • If the fascine is made from dead wood: no maintenance but lifespan of 2 to 4 years.
  • It can be made permanent with live wood added in the branches (cuttings).
  • The fascine must be pruned regularly depending on vegetation regrowth.
  • When upstream soil deposits are too large: add additional bundles between stakes to increase the fascine height.

Cost

Installation:

• DIY: €28/m (live) or €22/m (dead).
• By a company: €60 to 80/m (live) or €55 to 75/m (dead).