Erosion TTool/Creation and Maintenance of a Ditch Collectively

Technical articles - Erosion TTool - Érosion des sols

Grandes cultures Grandes cultures Erosion TTool

Illustration of the practice of collective creation and maintenance of a ditch within the serious game Erosion TTOOL. Credit: Delphine Hombrouckx

The role of the ditch is to collect and channel runoff water to prevent gully formation. Unlike swales, the ditch is not necessarily closed, it can be deep and its slopes are not necessarily gentle.

Description

Advantages

• Channels runoff water.
• Allows drainage.
• Can promote infiltration of water.
• Can temporarily store water and thus reduce damage caused during rainfall events.

Disadvantages

• Can harm biodiversity (reduced impact if grass strips or embankments or hedge are implemented).
• If poorly designed upstream, there is a risk of reduced soil infiltration capacity.

Implementation

• There are 3 types of ditch:
  • Transfer ditches which facilitate water passage (often near a drinking water catchment).
  • notched ditches which delay water arrival downstream of the watershed.
  • Ditches associated with an embankment which serve as runoff retention zones (often upstream of watersheds).  

• It may be useful to design the ditch according to the maintenance equipment.
• The ditch must be constructed under good soil bearing conditions to avoid degrading infiltration capacity in summer. It must therefore be quickly grassed.
• A grass strip can be placed upstream of the ditch to allow sedimentation of runoff and limit ditch siltation.

Advice

• It is recommended to maintain the ditch regularly, notably:
  • Mow around the ditches (twice a year).
  • An annual cleaning depending on observations.
• The use of phytopharmaceutical products around the ditch is prohibited.
• There are water filtration techniques in ditches (for example: placing straw bales to trap suspended solids and certain pesticides).
• It is advised not to connect rural ditches to the community's urban networks.