A swale is a water collection and distribution device. This swale is designed to collect the runoff from the parking lot and distribute it evenly across the field. Hopefully it will reduce the chronic wetness in the area below the swings.
Once a contour line has been surveyed and marked, it is used as the top line of the swale.
The bowl of the swale is a meter across and the berm below it is a meter across.
Insert shovel at a 30o angle along the top cut. Place sods upside down to start the berm.
The most important part is to level the bowl so that water caught by the swale will be spread out evenly along it.
The bowl and berm should be seeded with groundcover right away to preserve the life in the soil.
Later, the bowl can be filled with woodchips and inoculated with mushrooms.
We found rock near the surface in the parking lot drainage area, but further away we ran into deeper soil.
Video below: Our collective digging machine