You need to look to the requirements laid out in flood rules. If you meet those then you qualify for flood escrow exception.
Small lender exception. (1) Qualification. Except as may be required under applicable State law, paragraphs (a), (b), and (d) of this section do not apply to a bank:
(i) That has total assets of less than $1 billion as of December 31 of either of the two prior calendar years; and
(ii) On or before July 6, 2012:
(A) Was not required under Federal or State law to deposit taxes, insurance premiums, fees, or any other charges in an escrow account for the entire term of any loan secured by residential improved real estate or a mobile home; and
(B) Did not have a policy of consistently and uniformly requiring the deposit of taxes, insurance premiums, fees, or any other charges in an escrow account for any loans secured by residential improved real estate or a mobile home.
There is a discussion of the small lender exception beginning on p. 43 of the preamble.https://www.federalreserve.gov/newsevents/press/bcreg/bcreg20150622a1.pdf