Laserfiche WebLink
<br />- <br />- <br />I- <br />. <br />. <br />. <br />. <br />. <br />i. <br />i. <br />. <br />. <br />. <br />- <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />;. <br />. <br />. <br />. <br />,- <br />. <br />. <br />. <br />. <br />. <br />I. <br />. <br />. <br />. <br />. <br />. <br /> <br />Bosley Wash Drainage Master Plan Phase I: Watershed Floodplain Delineation <br />__ ~~~~~~rG.'E~P~?ti:if~;;,'1f~~f:i;i~~;;:~;;;"5;;',;';,'.", ~,~ <br /> <br />1.4 Hydraulic Modeling and Floodplain Delineation <br /> <br />Hydraulic profiles were computed for each of the afore mentioned recurrence intervals using <br />HEC,RAS (USACOE, 1990), Flood profiles were computed in accordance with CWCB <br />requirements, The type, size, capacity and location of major conduits, open channels, and storage <br />facilities were identified and included within the model. HDR developed model geometry using <br />a combination of aerial mapping supplied by the county, cross-sections surveyed by GJDD, and <br />USGS quadrangle maps, <br /> <br />2. BASIN DESCRIPTION <br /> <br />Bosley Wash is a right-bank tributary of the Colorado River located in Mesa County, Colorado, <br />The watershed is west of Palisade near unincorporated Clifton, Colorado, The watershed <br />consists of 3.3 square miles of highly varied terrain including rural, semi-urban, and desert <br />mountain environments, The Grand Valley, which includes the Bosley Wash Watershed, <br />displays characteristics typical of an arid, high-desert climate, <br /> <br />2.1 Basin Development <br /> <br />The Bosley Wash Basin is divided into two distinct watershed regions, Steep, unimproved <br />channels originating on the slopes of the Book Cliffs and Mt. Garfield characterize the upper <br />portion of the basin above 1-70, This portion of the watershed is undeveloped, with most of the <br />land privately owned, The lower part of this upper watershed is situated on a highly erosive <br />alluvial fan, capable of generating high runoff rates and large sediment loads during peak events, <br /> <br />The lower portion of the watershed, south of 1-70, consists of low-density residential and <br /> <br /> <br />agricultural areas, Throughout most of the lower watershed, the Bosley Wash drainage system <br /> <br />(including its tributary ditches) consists of drainage ditches that have been improved and <br /> <br /> <br />redirected along roads and railroads, <br /> <br />2,2 Irrigation Ditches <br /> <br />Four major operating irrigation canals cross the drainage basin below 1-70, These are: <br /> <br />. ,.;~~~'- "'fll",,f' <br />'jV~' <br />"~"~!c~t~ir..,t- <br /> <br />'n~1t~~~~~~~s.~;~~~~{,~,;};:"'l"" <br /> <br />. ~ <br /> <br />Page 3 <br /> <br />@'"{ <br />