When does Soil Erosion Occur

Each soil must be understood for its own traits. Often a civil engineer will be needed on the team.

I worked on a project where the soils were a crumbly shale. They were not going to erode but more likely would collapse. Now I am working on a project 45 miles from that one. Soils are old Great Lakes dunes, 98%sand. Easily eroded. Forest cover looked similar in each case.