Terreindrainage

Terreindrainage is the system for removing excess surface and subsurface water from land to improve soil conditions for agriculture, construction, or other land uses. Its primary aim is to prevent waterlogging, improve soil structure, and stabilize foundations by lowering the water table to an appropriate level. Drainage works can be classified as surface drainage, which directs runoff away through open channels, and subsurface drainage, which uses buried drainage pipes or tiles to collect and convey water to outlets.

Surface drainage typically relies on ditches, swales, and channels that capture runoff from rainfall and melting snow and carry it to streams, rivers, or artificial outlets. Subsurface drainage consists of perforated pipes installed in trenches, often with gravel or a filter material to prevent sediment intrusion, connected to an outlet or drainage network. Modern installations may include collector drains that gather water from multiple lines and discharge it through a controlled outlet.

Design considerations include soil type and permeability, the depth of a water table, topography and slope, rainfall patterns, and land use. Drain spacing, depth, and pipe size are chosen to achieve a target drainage performance. Installation requires trenching, proper bedding, placement of pipes, backfilling, and outlet construction, followed by maintenance such as cleaning, inspection, and replacement of damaged sections.

Environmental aspects include potential changes in soil aeration or nutrient leaching, groundwater level impacts, and regulatory requirements for water quality and discharge. Terreindrainage is widely used in crop production, forestry, and construction in areas prone to heavy soils and high water tables.