Below is FEMA's response from "Ask the Experts" when asked the question. You'll notice that it never says there is no need to get the insurance, instead it says to exclude the building from the security interest...interesting.
"You asked whether flood insurance is necessary for a building valued at $1,000 or less with a $1,000 deductible.
FEMA publishes a booklet, Mandatory Purchase of Flood Insurance Guidelines, which is available online,
http://www.fema.gov/library/viewRecord.do?id=2954. On page 29, the following is noted: “If the land has a building on it and the lender has a security interest in that building, the lender must require the purchase of flood insurance to protect its security interest.” In the situation you describe, it would seem illogical to require flood insurance. One way to avoid this situation is to explicitly exclude the building as collateral for a loan. The Federal flood insurance requirement applies to a structure in a Special Flood Hazard Area that carries a mortgage backed by a federally regulated lender or servicer. If the building is not part of a mortgage agreement, there is no Federal flood insurance requirement."