Installing backflow valves, which are designed to block drain pipes temporarily and prevent return flow, protects property from sewage backups. Backflow valves are available in a variety of designs that range from the simple to the complex. Flooding can cause sewage to back up through drain pipes, leading to damage that is difficult to repair and is a health hazard.

To protect property from sewage backups, the Federal Emergency Management Agency (FEMA) suggests installing backflow valves, which are designed to block drain pipes temporarily and prevent return flow. Backflow valves are available in a variety of designs that range from the simple to the complex.

Among the simpler valves are flap or check valves, which open to allow flow out of the structure but close when the flow reverses. Check valves operate automatically but do not provide as strong a seal as a gate valve.

FEMA reminds homeowners that:

Having a plumber or contractor install one backflow valve will cost about $1,400 for a combined gate/flap valve or about $600 for a flap valve, according to FEMA. Those figures include the cost of excavation and backfilling.