Stormwater is water from rain or melting snow that does not soak into the ground. It flows from rooftops, over paved areas such as driveways, roadways and parking lots. As it flows, stormwater runoff collects and transports animal waste, litter, pesticides, fertilizers, oil & grease, soil and other potential pollutants. Eventually, these stormwater pollutants go directly into streams and rivers with no treatment. This is known as stormwater pollution.