Land remodeling

After mining, the soil is destabilized and impoverished. It is therefore necessary to allow future revegetation activities to remodel these soils.
This first involves geotechnical expertise in order to define the work to be carried out to ensure the stability of the structure over time.

The work can be of several types and depends on the structure and texture of the soil, the slope, the surface of the area and its location within the mine (possibility of diverting water to the forest). One of the methods used is slope smoothing at a slope of approximately 20° to 25°. However, if the integrating slopes are too high, the creation of successive benches can be considered.

The work is systematically carried out in the dry season. The machines provided by SMSE for this remodeling are: 290 hydraulic excavator, 450 hydraulic excavator, bulldozer.

Managing runoff is essential to combat erosion and sustain remodeling. In the case of the creation of a uniform slope, the SMSE sets up ditches following the level curves (see photos).

Once the soil has been remodelled, the topsoil stored at the begining of excavation can be brought and applied in different ways (covering, windrows, mounds, etc.), it will greatly facilitate the re-vegetation work to be followed by providing better living conditions for planted trees, while bringing directly to the site the microorganisms and bacteria necessary for life and soil fertility reconstruction.

Travail du sol : pente douce et fossés en courbes de niveau

Banquettes avant enherbement (St-Auguste 2017)

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Enherbement courbes de niveau (Espérance 2014)

Banquettes enherbées (St-Auguste 2018)

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Creek replacement

When the gold mining is alluvial, the stream has been diverted for the duration of the mining. One of the challenges of rehabilitating the site is therefore to put the rivers back in their original beds.

The process takes place in several stages:

 

  • 1 : Connect the ponds from upstream to downstream by alternating the passage of water. Let the ponds decant, then open the downstream pond on the creek to purge it.
  • 2 : Lay the sand and gravel on the future bed of the creek by describing meanders in order to reproduce the original route of the creek.
  • 3 : Fill the ponds gently sloping up to the creek.
  • 4 : Place a few trunks or large blocks of stone at the edge of the creek to slow the current and limit erosion. Spread topsoil, tree trunks and other plant waste nearby to cover the soil.
  • 5 : Partially open the upstream of the creek for re-watering. Consider creating vehicle access to facilitate the revegetation of the site (ramps, neat slopes).
  • 6 : Wait one day for the complete release, fill in the upstream to downstream diversion channel.

Repositionnement cours d'eau

Repositionnement cours d'eau

Repositionnement cours d'eau

Repositionnement cours d'eau

Repositionnement cours d'eau

Repositionnement cours d'eau