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1 <br />1 <br />1 <br />n <br /> <br />1 <br /> <br /> <br />I <br /> <br />5.0 INTERPRETATION OF THIS REPORT <br />5.1 Hydrologic Findings <br />The results of the hydrologic analysis for the White River are considered accurate. They are <br />based in part on existing approved data. <br />5.2 Hydraulic Findings <br />The hydraulic methods used for this study are similar to those used in more detailed studies and <br />much more detailed than the typical approximate studies. The 100-year flood depths range from <br />7.4 feet in a medium width reach of the river to 13.1 feet at the downstream limit of the study. <br />The flood depths are generally consistent throughout the study reach with differences of a few <br />feet (8-13 feet for 100-year flow depths). <br />5.3 Floodplain Delineations <br />The primary difficulty in presenting precise delineation of the 50-year and 100-year floodplains <br />was the limited quality of the available base mapping for the lower White River. Using USGS <br />topographic quadrangle maps at contour intervals of 20 or 40 feet to portray flood lines in <br />unsurveyed areas provides limited information. The margin for interpretation is very great, <br />especially in wider reaches of the river where contours are widely spaced. More detailed <br />topographic information will be needed in areas of specific interest. <br />This study can be utilized to prepare more detailed floodplain delineations in such areas of <br />specific interest. Those who are interested in greater detail have three choices for using this <br />study: <br />' 1) They can refer to the detailed study information for the stream reach in and around <br />Rangely; <br />2) They can rely on the hydrologic determinations and use other topographic information and <br />' hydraulic models; or <br />3) They can use the depth calculations with other topographic information from field surveys <br />or other maps. <br /> <br /> <br />1 <br /> <br />22 <br />