A raindrop is like a miniature water bomb: it hits the
ground at 20 miles per hour. When raindrops hit bare soil, water can
splash soil up to 6 feet away, carry particles away, and drop sediment
into drainageways. Wind also dislodges, moves, and transports soil
particles. We need that topsoil; it nourishes our food and allows us to
live, but it can take almost 1,000 years to be created (Oregon
Association of Conservation Districts 2007). In Portland specifically,
composted soil can be made in a week (Plantea 1998).