Laserfiche WebLink
<br />I <br />I <br />'I <br />I <br />I <br />I I <br />I <br />I <br />I <br />'I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />Hvdraulic Analvsis <br />Hydraulic methods used for the approximate floodplain delineations shown on the Arapahoe <br />County FIRM panels are not available or have not been documented by FEMA. For future <br />studies, an approximate loo-year flood elevation at a particular location on the river may be <br />obtained by using the loo-year peak flow value (as provided in this report) in conjunction with <br />an acceptable hydraulic analysis. Hydraulic analyses for determining loo-year water surface <br />elevations for approximate floodplains may be performed using FEMA's Quick-2 computer <br />program, the Corps of Engineers' HEC-2 computer program, F1owmaster, or other acceptable <br />hydraulic methods. Channel and floodplain cross-sections may be obtained from detailed <br />topographic mapping or from field surveys. Cross-sections obtained from USGS quadrangle <br />maps are not advised. <br /> <br />Floodplain Mappin!! <br />The existing FIRM for Arapahoe County depicts areas subject to loo-year flooding based on <br />approximate technical methods. The map does not show flood profiles, base flood elevations, or <br />sufficient detail in order for County officials, engineers, developers, and land owners to make <br />floodplain determinations with any certainty. The Colorado Water Conservation Board can be <br />contacted to request technical assistance for approximate floodplain analyses as needed, <br /> <br />lO <br />