Rocks piled to look like stairs along a hillside that helps with drainage.
https://www.codot.gov/projects/i70floydhill/photos/september-2023-photos/10_9_23-drainage-feature-1.jpg/view
https://www.codot.gov/projects/i70floydhill/photos/september-2023-photos/10_9_23-drainage-feature-1.jpg/@@download/image/10_9_23 Drainage Feature 1.JPG
Rocks piled to look like stairs along a hillside that helps with drainage.