Backwater overflow devices are plumbing fixtures that are effective at preventing sanitary sewer overflows into homes. They use a float/seal mechanism that automatically opens if water begins to back up. This allows the overflow to occur outside the home. To ensure the device can function properly, make sure it is not blocked or covered by landscaping.
Backwater overflow devices are required on all new houses and must be installed whenever a lateral/side sewer is repaired or replaced. They are available in a variety of models and price ranges. These devices can be installed by a licensed plumbing contractor or the homeowner.
After installation, an inspection by WCW and a Certificate of Compliance is required. If a new cleanout is necessary, a WCW sewer permit is required.
WCW recommends all homes install a backwater overflow device. To find out if a property already has one, check the exterior of the home or, for assistance, call WCW at (510) 222-6700.