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<br />;; <br /> <br />. <br /> <br />. <br /> <br />September 4, 1997 <br /> <br />in the "FIRM, City of Boulder, Colorado, Boulder COW1ty, CommW1ity-Panel Number 080024 0185 <br />D, revised August 4, 1988." This same floodplain delineation has additionally been reflected in the <br />"FIRM, City of Boulder, Colorado, Boulder County, CommW1ity,Panel Number 080024185 E, <br />revised May 3, 1990," and the "FIRM, Boulder COW1ty, Colorado and Incorporated Areas, Map <br />Number 08013C0555, effective JW1e 2, 1995." <br /> <br />Following thorough analysis of the G&O South Boulder Creek floodplain study, specifically in the <br />stream reach between South Boulder Road and Colorado State Highway 93, errors and omissions <br />have been discovered that dramatically affect existing residential neighborhoods within the City. <br />These neighborhood impacts were not revealed in the G&O study and were not identified in previous <br />FIRMs. In addition, the G&O study defined significantly narrowed floodplain bOW1daries upstream <br />ofU.S, 36 when compared with the uniformly wide floodplain bOW1daries defined in the R.W. Beck <br />and Associates, UDFCD, Maior Drainageway Planning. South Boulder Creek. Volume II, December <br />1973 (Attachment C), study adopted in the original "FIS, Boulder County, Colorado <br />(Unincorporated Areas), August 1978." This floodplain change is apparently based on G&O's <br />incorporation of a man,made earthen embankment on the Flatiron Property, :! local gravel mine. <br />No explanation for this significant floodplain change is included in the G&O study and there is no <br />backgroW1d information to support that this embankment was ever approved by FEMA as a flood <br />protection levee. Because of this, the City of Boulder believes that use of the G&O study for <br />floodplain regulation should be suspended, pending a detailed analysis and investigation by FEMA. <br /> <br />The City's concerns have been heightened by the recent catastrophic flooding from Spring Creek <br />in Fort Collins, Colorado, which claimed five lives and caused millions of dollars in damages to the <br />facilities of the Colorado State University and surroW1ding neighborhoods. The Spring Creek flood <br />was exacerbated by the overtopping and failure of man, made earthen features, and by the very <br />intense localized rainfall that has become increasingly common along the Front Range. The South <br />Boulder Creek situation is similar in that an earthen man,made berm has been added in the <br />floodplain and the University of Colorado, now owner of the Flatiron Property, and surroW1ding <br />neighborhoods are located downstream of this feature. The University has identified the Flatiron <br />Property as their future southern campus, which may add to the potential flood risks posed by flash <br />flooding along the Front Range. Boulder has been regarded to be at the greatest risk for flooding <br />in the state of Colorado, with flooding potential compared to that of the 1976 Big Thompson flood <br />which claimed 139 lives. <br /> <br />The City of Boulder has been notified by the Flatiron Property land owner and mining operator that <br />they intend to file application with FEMA for flood protection levee certification approval once <br />technical analyses for engineering certifications and additional improvements to the berm to satisfY <br />levee design standards have been finalized. Therefore the City believes that immediate FEMA <br />action is needed. <br /> <br />2 <br />