Soil Piping

Soil piping is the subsurface erosion of soil or unconsolidated sediment by percolating groundwater that concentrates into underground conduits, or pipes, along zones of weakness such as root channels, cracks or permeable soil horizons. As a pipe enlarges it can undermine the ground above until the roof collapses, producing a line of sinkholes or a gully that appears to form without any surface channel ever having been cut, a hazard for earthen dams and levees as well as a natural driver of badland and gully development. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/