A backwater valve is a plumbing device that is installed in the sewer line of a home or building to prevent sewage from flowing back into the building during a sewer backup. A backwater valve works by automatically closing off the sewer line when water flows in the opposite direction, such as during a heavy rainstorm or when a nearby sewer line becomes blocked. This helps to protect the home or building from potentially hazardous and damaging sewage backups, which can cause significant damage and pose health risks to occupants. Backwater valves are typically required by local building codes in areas with a high risk of sewer backups, such as homes located near flood-prone areas or with basements below the level of the street or sewer lines. They are typically installed by licensed plumbers and require regular maintenance to ensure they are functioning properly.
