There are some homeowner endorsements that will cover a back-up or overflow of sewers or drains or a sump-pump. These type losses sometimes do occur during flooding events. These endorsements will often have dollar limits substantially less than the flood policy
90% of all natural disasters have some form of flooding.
25% of homes with flood claims each year are in low risk zones.
Private insurance companies and the federal government recognized that their association would improve the overall success of the program. Accordingly, insurance companies administer the program, but the federal government funds the insurance.
If a house is destroyed due to the collapse of the land it is built on, and the collapse is due to waves or currents of water, that would be considered a flood and would be covered.