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All requests that involve changes to floodways should be submitted to the appropriate FEMA Regional Office. The Regional Offices and their addresses are listed in Appendix D. Required Supporting Data Floodway revisions cannot be made without adequate supporting data. Because many States require communities to follow administrative procedures for establishing and revising floodways and because the limits of the floodway are established through engineering analyses, both legal documentation and technical data must be submitted. Also, it is important to note that as the floodway fringe is developed, an increasing amount (if not all) of the allowable surcharge is used. Therefore a revised floodway must be configured in such a way that it wi II conti nue to convey the 100-year flood discharge with no greater than a 1.0-foot increase in the original BFEs (i.e., the BFEs on which the unrevised floodway is based) at any pOint. If the floodway revision is part of a revision that results in BFEs lower than those on the map that is to be revised, the 1.0-foot surcharge limit applies to those lower BFEs. In the followi ng are descri ptions of the documentation and data that the requestor must submit to support each type of floodway reVISion. All Floodway Revisions The following documentation must be submitted as evidence that the community is prepared to adopt the revised floodway and that all legal requirements will have been met before the floodway is revised: . Copy of a public notice stating the community's intent to revise the floodway and a statement that the community has notified any affected property owners or adjacent jurisdictions. . Copy of a letter notifying the State of the floodway revision . Documentation of the approval of the revised floodway by the appropriate State agency (for communities where the State has jurisdiction over the floodway or its adoption by communities participating in the NFIP) Floodway Revisions Made as Part of an Appeal or Map Revision The following data must be submitted: . Engineering analysis for the revised floodway, performed according to the steps below: 1. The floodway analysis should be performed for the desired floodway limits with the hydraul ic computer model used for the determination of the new BFEs for the Appeal or Map Revision. (See Chapter 3 or 4.) 2. The floodway limits should be set so the combined effects of past encroachments, the changes on which the Appeal or Map Revision is based, and the new floodway limits do not increase the original BFEs or those resulting from the Appeal or Map Revision by more than the amount allowed by FEMA and the State. (Copies of the input and output data from 'he original, modified, and flooc' .,ay computer models must be submitted.) . Delineation of the revised flood way on the same topographic map used for the delineation of the revised floodplain boundaries resulting from the appeal or map revision. 41