When does slope erosion become a structural problem?

Slope erosion becomes structural when it begins affecting drainage systems, adjacent foundations, or the load-bearing capacity of soil supporting structures. Surface erosion that exposes subsoil changes drainage patterns, redirecting water into the slope face and increasing saturation. Saturated soil exerts increased lateral pressure on any foundation or structure downslope. Once erosion is visible on the surface, subsurface soil movement has typically been underway for longer than the visible damage suggests.