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<br />, ~ , <br />I , <br />, <br />'" , <br /> <br />the COE's modeling effort for Barnard Creek. At that time, similar flood hazard <br />delineations were completed by the COE for other alluvial fans along the Wasatch Front <br />, <br />including those for Ricks and Parrish Creeks. <br />Since the 1988 study, map revisions for Ricks Creek and Parrish Creek alluvial fans, <br />located contiguous to the Barnard Creek drainage to the north and south respectively, have <br />been completed (Fig. 2). The restudy of Barnard Creek alluvial fan flooding is being <br />prepared for the City of Centerville by FLO Engineering. The FIRM revisions for Ricks <br />and Parrish Creeks were based on revised estimates of the sediment volume predicted for <br />the 100-year flood event. The revised estimates were published in a document, "Centerville <br />Utah, Debris Flow Hazard," prepared by the Davis County Public Works and Flood Control, <br />1990. <br /> <br />The Barnard Creek FIRM flood zones on the Centerville map includes a Zone A <br />near the fan apex where no flood base elevations have been determined, a Zone X <br />indicating areas determined to be inside the SOD-year flooding or areas within the 100-year <br />flood boundary with average depths les~ tpan one foot, a Zone AH and Zone AO at the <br />terminus of the fan indicating flood depths of I to 3 ft usually resulting from ponding of <br />flood waters or flooding related to sheet flow on sloping terrain (See Fig. 1). It is the Zone <br />A delineation near the fan apex which encompasses the property boundary for which the <br />LOMA is requested. <br />Since Barnard Creek alluvial fan Zone A has incorporated the COE's mud flow <br />delineation, a review of the model and its application were required. The COE model's <br />technical problems had been previously investigated and the consequences of its application <br />to Barnard Creek flood hazard delineation were readily apparent (O'Brien and SLA, FIS; <br />1989). The resulting inaccuracies in the current Zone A mapping are function of two <br />factors: 1) the COE model's inability to simulate flow over complex topography and 2) the <br />extraordinarily large sediment volume assigned to the 100-year flood. <br /> <br />III. Property Location <br />The City of Centerville is located on several coalescing alluvial fans. The Barnard <br />Creek Fan is located approximately in the center of the corporate limits of the City. The <br />property boundary in question as shown on Fig. 3 is bounded by Chase Street on the North <br />and 400 East Street on the West. The property is a parcel of undeveloped land, The <br /> <br />2 <br />