Abstract: The present invention provides an open-topped flood-prevention sump well extension. A cylindrical wall placed around a sump pit extends above the floor level to the proximity of a sewer or septic drain. A connecting pipe automatically drains the overflow attendant to a malfunctioning or overloaded sump pump to the sewer or septic system. A means for preventing backflow of sewer discharge is provided by a one-way valve or a plumbing trap. An alarm system is provided for signaling rising water level.