Erosion is considered a problem in the Southwestern United States. However, erosion itself is a natural process. Overgrazing of the land and human development have stripped the topsoils, and concentrated water-flow from precipitation into areas which cannot contain it effectively (i.e. parking lots, paved roads, etc).  In a healthy watershed, erosion is a very slow process that is kept in balance with vegetative cover, and living, porous soils.  In unhealthy watersheds, erosion runs unchecked, which leads to rapid water-loss, soil-loss, and overall decline in ecological health.