From a guy in the mortgage business:

Jonah,
Homeowners insurance NEVER includes flood insurance. However, federal law says, and EVERY mortgage lender requires, that home owners carry flood insurance if their home is in a flood zone. If your home is paid for, Derb, and you are in a flood zone you are still required by law to carry flood insurance.
It is sold by virtually all insurance carriers, the price is federally mandated so the cost is the same no matter who you purchase it from.