What is alluvial soil?
Alluvial soil is formed from water deposits, or is a water deposit. If you will notice during a rain, or a flooding situation, where water will stand for a while, and then after the water recedes, the area up against the wall or a fence, or on the side of a building where the water was, that is alluvial soil. You take those scrapings off of there, and that is what that is.