As the name implies, stormwater is water from a storm (rain, melting snow, or ice). Stormwater runoff is stormwater that does not soak into the ground, but flows across outdoor surfaces like roads, sidewalks, lawns, driveways and parking lots, and drains into water bodies. Unlike water used within homes and businesses which flows to a water treatment plant, stormwater runoff is not treated and flows directly to rivers, streams, and oceans.