Flood insurance is a type of property insurance that covers a dwelling for losses sustained by water damage, as it specifically relates to flooding. A separate coverage rider is needed to cover sewer backup, if the backup was not caused by the rising floodwaters. A typical homeowner policy does not include flood insurance.
Earthquake insurance is a form of property insurance that pays the policyholder in the event of an earthquake that causes damage to the property. Most ordinary home owners policies do not cover earthquake damage. Rates depend on location and the probability of an earthquake loss.