The primary purpose of storm drains is to carry rainwater away from development to prevent flooding. Storm drains are not connected to sanitary sewer systems and water treatment plants. Many people don't realize that untreated stormwater and the pollutants it carries flow into the streams, creeks, rivers, and oceans where wildlife live and children play. Stormwater pollution occurs when water rinses off streets, housing, parking lots, and businesses into our gutters and storm drains, taking with it yard waste, litter, trash, grease, household cleaners and solvents, animal and human waste, lawn and garden fertilizers, and soil erosion. Every year, streams, creeks, rivers, and lakes are degraded by pollution.