FA (General Floodplain Area): the areas identified as Zone A in the FIS for which no one-hundred-year-flood elevations have been provided. When available, information from other federal, state and other acceptable sources, including those areas shown as alluvial soils in the Chester and Delaware Counties Soil Survey, shall be used to determine the one-hundred-year elevation, as well as a floodway area, if possible. When no other information is available, the one-hundred-year elevation shall be determined by using a point on the boundary of the identified FIRM which is nearest the construction site in question. In lieu of the above delineation method, the Township may require the applicant to determine the elevation with hydrologic and hydraulic engineering techniques. Hydrologic and hydraulic analyses shall be undertaken only by professional engineers or others of demonstrated qualifications approved by the Township who shall certify that the technical methods used correctly reflect currently accepted technical concepts. Studies, analyses and computations shall be submitted in sufficient detail to allow a thorough technical review by the Township.