Pervious pavement systems provide stormwater management. Water drains through the pavement to a cleansing layer of gravel. The gravel or stone acts as a natural filter, clearing the water of pollutants. The EPA Storm Water Phase II regulations provide programs and practices to help control the number of contaminants in our waterways. Traditional concrete and asphalt hardscapes collect oil, anti-freeze, and other automobile fluids that can be washed into streams, lakes, and oceans when it rains.