Soil water repellency causes more runoff and erosion. An experiment on water-repellent soil without plants showed high runoff and erosion rates. The steeper the slope, the more runoff and erosion occurred. Adding a surfactant reduced runoff significantly. Initially, water formed beads and rivulets on the soil surface, but later a protective water layer reduced soil contact. Small rain events on water-repellent soil led to high runoff but potentially less erosion. Erosion preferentially removed silt and clay, along with organic carbon, nitrogen, and nutrients from the soil.