Name: greene Savannah, GA (Sunset 28) (Zone 8b) I have no use for internet bullies!
I have to admit I had no clue what a "level spreader" was but now I see it is an erosion control method. So basically what you have is a rain garden, sometimes full/sometimes dry.
The cairn would add visual interest.
Sunset Zone 28, AHS Heat Zone 9, USDA zone 8b~"Leaf of Faith"