The storm drain system exists to prevent localized flooding by directly transporting excess stormwater runoff (rain that doesn’t soak into the ground) and irrigation water from neighborhoods and streets to local creeks and rivers.
The storm drain system includes underground pipes, as well as surface features such as drain inlets, streets, gutters, roadside ditches, and detention basins. Virtually all outdoor drains lead to the storm drain system!
The water entering the storm drain system is not treated to remove pollutants. Stormwater flows through the storm drain system to our local waterways. Any pollutants that enter the storm drain system end up in our creeks and rivers where they can harm the environment.
In contrast, the sanitary sewer system is designed to carry wastewater from residential, commercial and industrial sources to a treatment plant where pollutants are removed before treated water is discharged.
Commercial carwash facilities dispose of their wastewater to the sanitary sewer system—that’s why we encourage fundraising groups to consider partnering with a commercial carwash for their fundraising events!