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<br />vertical datum used for newly created or revised FIS reports and FIRMs was <br />NGVD29. With the completion of the North American Vertical Datum of 1988 <br />(NA VD88), many FIS reports and FIRMs are now prepared using NA VD88 as <br />the referenced vertical datum. <br /> <br />Flood elevations shown in this FIS report and on the FIRM have been converted <br />to NA VD88. Table 5 shows individual datum conversion elevations for each <br />stream studied in this community. <br /> <br />Table 5, "NGVD29 to NA VD88 Conversion Elevations" <br /> <br /> Conversion from NGVD to <br />Stream Name NA VD (feet) <br />Clear Creek at Georgetown +5.00 <br />Clear Creek at Idaho Springs +4.46 <br />Clear Creek at Silver Plume +5.25 <br />Chicago Creek +4.57 <br />Fall River +4.68 <br />Soda Creek +4.49 <br />South Clear Creek +5.02 <br />Virginia Canyon +4.47 <br /> <br />Flood elevations must be compared to structure and ground elevations referenced <br />to the same vertical datum. For information regarding conversion between the <br />NGVD29 and NA VD88, visit the National Geodetic Survey website at <br />www.ngs.noaa.gov, or contact the National Geodetic Survey at the following <br />address: <br /> <br />NGS Information Services <br />NOAA, N/NGS12 <br />National Geodetic Survey <br />SSMC-3, #9202 <br />1315 East-West Highway <br />Silver Spring, Maryland 20910-3282 <br />(301) 713-3242 <br />(301) 713-4172 (fax) <br /> <br />To obtain current elevation, description, and/or location information for <br />benchmarks shown on this map, please contact the Information Services Branch <br />of the NGS at (301) 713 3242, or visit their website at www.ngs.noaa.gov. <br /> <br />4.0 FLOODPLAIN MANAGEMENT APPLICATIONS <br /> <br />The NFIP encourages state and local governments to adopt sound floodplain management <br />programs. To assist in this endeavor, each FIS report provides I-percent-annual-chance <br />floodplain data, which may include a combination of the following: 10-, 2-, 1-, and 0.2- <br />percent- annual-chance flood elevations; delineations of the 1- and 0.2-percent-annual- <br />chance floodplains; and a I-percent-annual-chance floodway. This information is <br />presented on the FIRM and in many components of the FIS report, including Flood <br /> <br />11 <br />