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Revisions Based on Use of an Alternative Methodology For an alternative hydrologic methodology, the following data must be submitted: . New hydrologic analysis based on alternative methodology . Explanation for superiority of alternative methodology . New hydraulic analysis based on flood discharge values from new hydrologic analysis . Revised delineations of floodplain and floodway boundaries on a topographic map . Annotated copies of FHBM, FIRM, FBFM, Flood Profiles, and FIS report tables, as appropriate, that show requested Tevisions For an alternative hydraulic methodology, the following data must be submitted: . New hydraulic analysis based on alternative methodology and origi nal flood discharge values . Explanation for superiority of alternative methodology . Revised delineations of floodplain and floodway boundaries on a topographic map . Annotated copies of FHBM, FIRM, FBFM, flood profiles, and FIS report tables, as appTopTiate, that show requested revisions Revisions to Correct Indisputable Errors in Original Analysis For a mathematical error, the requestor must identify the error; FEMA will perform new calculations to correct the error. For a measurement error, the requestor must identify the error and provide the correct measurement; FEMA will perform new calculations to correct the error. Revisions to Exclude Individual Structures and Legally Described Parcels of Land From SFHA Based on Altered Topography (Placement of Fill) The determinations and changes made by FEMA will be similar to those described in Chapter 6. The requestor must provide data that verify the location of the structure or parcel of land and show that the structure or parcel of land is not subject to flooding during the base flood Therefore, the required supporting data generally will be the same as those for a request for a map amendment. However, because the requests will involve alterations of topography that occurred after the effective date of the first NFIP map that showed the structure or parcel of land to be within the SFHA, the following additional requirements will also apply: . For all such revision requests, the requestor must demonstrate that the placement of fill has not resulted in an encroachment within the regulatory floodway. . When the revision request involves more than a single structure or a single parcel of land, the requestor must demonstrate that the fill placed to elevate the structures or parcels will not settle belOW the BFE and that the fill is adequately protected from the forces of erosi on, scour, or differential settlement. Therefore, data must be submitted which show that the requirements below have been met. 1. All fill placed for pads for residential and commercial structure foundations must be compacted to 9S percent of the maxi mum density obtainable with the Standard Proctor Test method developed by the American Society for Testing and Materials (ASTM Standard D-698) 2. Fill slopes for granular materials must not be steeper than one 22