(A) Zone A:
(1) Within Zone A areas designated on an effective FIRM, data from the preliminary FIRM and/or FIS shall be reasonably utilized as best available data.
(2) When all appeals have been resolved and a notice of final flood elevation determination has been provided in a Letter of Final Determination (LFD), BFE and floodway data from the preliminary FIRM and/or FIS shall be used for regulating development.
(B) Zones AE, A1-30, AH, and AO:
(1) BFE and floodway data from a preliminary FIS or FIRM restudy are not required to be used in lieu of BFE and floodway data contained in an existing effective FIS and FIRM. However:
(a) Where BFEs increase in a restudied area, communities have the responsibility to ensure that new or substantially improved structures are protected. Communities are encouraged to reasonably utilize preliminary FIS or FIRM data in instances where BFEs increase and floodways are revised to ensure that the health, safety, and property of their citizens are protected.
(b) Where BFEs decrease, preliminary FIS or FIRM data should not be used to regulate floodplain development until the LFD has been issued or until all appeals have been resolved.
(2) If a preliminary FIRM or FIS has designated floodways where none had previously existed, communities should reasonably utilize this data in lieu of applying the encroachment performance standard of Section 1266.34(B) since the data in the draft or preliminary FIS represents the best data available.
(C) Zones B, C, and X:
(1) Use of BFE and floodway data from a preliminary FIRM or FIS are not required for areas designated as Zone B, C, or X on the effective FIRM which are being revised to Zone AE, A1-30, AH, or AO. Communities are encouraged to reasonably utilize preliminary FIS or FIRM data to ensure that the health, safety, and property of their citizens are protected.