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<br />follows a flowpath that can be defined as, and is in the form of, <br />concentrated riverine flow with average depths in excess of <br />2 feet. Based on FEMA' s reevaluation, the Special Flood Hazard <br />Area (SFHA) for this area was redelineated and designated as <br />Zone AE with base (lOO-year) flood elevations (BFEs) shown. <br /> <br />e' <br /> <br />The hydraulics along Sand Creek between the 1-70 and the UPRR <br />bridges were also reevaluated. A split-flow condition exists <br />along the north bank of Sand Creek from approximately 200 feet <br />downstream of Cross Section N to the UPRR bridge. Using the <br />HEC-2 split-flow option, it was determined that a total of <br />12,239 cfs is lost from the Sand Creek base flood flow through <br />this reach. Flow between the ridge along the north bank of Sand <br />Creek and the south bank of the low-lying area adjacent to 1-70 <br />is shallow overland flow with average depths of 1 foot. The SFHA <br />delineations along Sand Creek and the low-lying area adjacent to <br />1-70 were revised slightly. The BFEs along Sand Creek have been <br />lowered as a result of this overflow condition. The floodway <br />designation through this reach of Sand Creek has been removed, <br />since this overflow cannot be fully confined to Sand Creek <br />without exceeding the I-foot surcharge limit for floodways. <br /> <br />~ <br /> <br />The 100-year water-surface profile for Westerly Creek is not <br />impacted by the revision to this reach of Sand Creek. <br /> <br />This revision is shown on Flood Insurance Rate Map Panels 0006 <br />and 0012. Profile Panels 80P-82P; Table 1, "Flooding Sources <br />Studied by Detailed Methods;" Table 2, "Summary of Discharges;" <br />and Table 3, "Floodway Data," were revised as part of this <br />reV1S1on. Profile Panels 97P-98P were added to the Flood <br />Insurance Study report. <br /> <br />(j, <br /> <br />.' <br /> <br />69 tr u.s. GOYERH"T PRIMTtttG OFFICE: 1995 - 404.]24/20320 <br />