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<br />. <br /> <br />NHD is not available nationwide). Streams identified as flooding sources on <br />the FIRMs/FHBMs were digitized into the NHD layer (using georeferenced <br />FIRM Tiffs) if not already represented. Streams shown on the FIRMs that <br />were not identified as primary flooding sources were not included unless <br />already present in the NHD file. Stream names for detailed-study streams <br />were changed to match names given in the FIS text (if not already correct). <br />Names of streams in zones A, Shaded X, and/or X were not altered from the, <br />original NHD file. <br /> <br />Effective Streams are a subset of the Source Streams and include those <br />stream segments that: <br /> <br />· Are specifically named in the effective FIS report (Le. have an <br />associated flood profile), OR <br />· Are within a Special Flood Hazard Area inundated by 1 DO-year flood <br />and are determined, during Prescoping process, to be a primary <br />flooding source for the area (includes streams not listed in the FIS <br />text). <br /> <br />NOTE: For A zones only those streams determined to be the primary <br />source of flooding are included in the Effective Streams file (i.e. backwater <br />stream segments are NOT included in the Effective Streams file). <br /> <br />. <br /> <br />Stream files are provided on the accompanying CD to show level of study <br />performed on streams during last flood mapping effort and as a basis for <br />prioritizing community requests for future study. Files provided have not been <br />checked for spatial and topological accuracy and should not be used for <br />engineering or final mapping purposes. <br /> <br />Considerable variation in stream sinuosity occurs between high and medium <br />resolution NHD layers and NHD data may not truly reflect current ground <br />conditions. Effective Stream lengths are not verified against stream lengths as <br />shown on FIRMs or as given in the FIS text. Therefore, stream lengths <br />derived from Source Streams file and Effective Streams file should not be <br />used for project-budgeting purposes. Approximate stream lengths for each <br />classification are included in the table below. <br /> <br />Zone Type <br /> <br />Approximate Study Streams. No BFE <br />Detailed Study Streams - BFE <br />Determined <br />Detailed Study Streams - With <br />Floodway <br />TOTAL <br /> <br />Stream <br />Length (ft) <br />4,509,991 <br /> <br />Stream <br />Length: (mi.) <br />854.16 <br /> <br />34,408 <br /> <br />6.52 <br /> <br />1,243,136 <br />5,788,993 <br /> <br />235.44 <br />1096.4 <br /> <br />. <br /> <br />4 <br />