Wing ditches can be used to effectively divert runoff water from roadside ditches onto the forest floor. Water that is allowed to flow down steep slopes without being diverted out of the side ditch can gnaw at the roadbed, scour the ditch itself, and move soil downslope.
When installing wing ditches, try to follow the natural contour of the land. These structures should:
- Open into a flat spreader
- Have a slight upward “hook”
- Not discharged into streams
- Be spaced properly along the road
When constructing a wing ditch, try not to cut a narrow channel that has a sharp downslope angle. While this would quickly divert water away from the road, it may lead to additional erosion.