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appellant may be required to provide new information for a large portion of the map. . All analyses and data submitted by the appellant, including those that show mathematical or measurement errors, must be certified by a registered professional engineer or licensed land surveyor, as appropriate. . Appeals, except for those based on the effects of flood protection systems under construction that meet the previously listed requirements, cannot be based on the effects of proposed proj ects or future conditions. Therefore, any maps, plans, drawings, measurements, or ground elevation data submitted by the appellant must be certified as representing existing, or as-built, conditions. . Generally, when an appellant is required to submit hydrologic or hydraulic analyses, those analyses must be performed for the same recurrence interval floods studied in the FIS. For riverine, lacustrine, and coastal flooding sources studied by detailed methods, FISs include analyses of the 100-year flood and, usually, the 10-, SO-, and SOO-year floods. Often, a hydraulic analysis of the 100- year floodway is performed for riverine flooding sources. For sheetflow and alluvial fan flooding sources studied by detailed methods, most FISs include analyses of only the 100-year flood. Therefore, the extent of the hydrologic and hydraulic analyses an appellant may be required to submit is determined not only by the basis of the appeal but also the type of flooding source and the scope of the FIS. . Unless the appeal is based on the use of alternative models or methodologies, the hydrologic and hydraulic analyses an appellant submits must be performed with the models used for the FIS. FIS hydrologic analyses for riverine flooding sources are usually performed with standard engineering methodologies, such as flood-frequency analyses of stream gage data, or with computer models that are in the public domain, such as the U.S. Army Corps of Engineers (CO E) H EC-1 model or the U.S. Soi I Conservation Service (SCS) TR-20 model. FIS hydraulic analyses for riverine flooding sources are usually performed with the COE HEC-2 step-backwater model or a similar and widely accepted model, such as the SCS WSP-2 model, or the U.S. Geological Survey (USGS) WSPRO model. For the analysis of alluvial fan flood hazards and the hazards associated with coastal storm surge and wave action, including wave height and wave runup, FEMA has established or adopted special methodologies and computer models. For analyses of lacustri ne and sheetflow flood hazards, FEMA uses a variety of standard engineering models and methodologies. Appellants may request from FEMA copies of the input and output data from the model(s) used in a specific FIS or copies of other calculations Of analyses performed for the FIS. (See Appendix C.) . As required by Paragraph 6S.6(a)(6) of the NFIP regulations, when an appeal is based on the use of an alternative hydrologic or hydraulic model, the appellant must show that the model used has been reviewed and approved for general use by a Federal agency responsible for water resources activities or a notable scientific body, is well documented (with a user's manual that includes source codes), and is available to the general user (i.e., in the public domain and nonproprietary). . Although requests for revisions to floodways do not qualify as appeals, the data on which successful appeals are based often include new floodway analyses. For information concerning additional data that must be submitted in support of appeals that involve changes to floodways, refer to Chapter 7,"Floodway Revisions". 1S