Why Would Living on a Floodplain Behind a Levee Be

Why would living on a floodplain behind a levee be safe from flooding?

A) Levees are rarely overtopped.
B) Water cannot seep under levees to flood the floodplain.
C) Levee banks are rarely eroded enough to fail.
D) Once a levee is built high enough to contain a 100-year flood, that volume of water will never flood.
E) This statement is not true because 100-year flood levels often continue to get higher with time.