Los Angeles Basin, Santa Clara River Basin, and Antelope Valley are divided into zones that yield similar volumes of sediment under similar conditions. These are called Debris Potential Area (DPA) zones. Sediment production from a watershed is a rate at which sediment passes a particular point, usually expressed as cubic yards per square mile per storm. The sediment production is dependent upon many factors such as: rainfall intensity, geology, soil type, vegetative coverage, runoff, and watershed slope.