FLOOD03463 - Laserfiche WebLink

Home Browse Search

I I I I I I . -3- Road structures, irrigation structures and other facilities located along the gulch were field surveyed by the Bell Mapping Company. Field measurements taken at these structures provided a basis for the hydraulic analysis completed for the flood plain delineation. of approximately 9.1 miles. The South Tributary study reach extends from the confluence with the mainstream to Ramstetter Reservoir, just east of Foothills Road (County Road 93), a length of 3.0 miles. The total study length is approximately 12.1 miles. - STUDY AREA DESCRIPTION - The basin is long and narrow with an average width of 1.3 miles. The basin widens above and below the hogback and becomes narrower through the lower reaches. The shape of the basin affects the hydrology in that the time of concentration for the total basin is totally out of phase with the lower subbasins. The average basin slope is 3.3%. The basin slope ranges from 8% in the upper reaches above the hogback to 0.7% in the lower reaches, above the confluence with Ralston Creek. There are two major irrigation reservoirs within the basin, Hyatt Lake and Ramstetter Reservoir. Both of these facilities have a hydrologic effect on storm runoff. Two smaller reservoirs are located near Hyatt Lake, as well as others throughout the basin. These smaller reservoirs were not considered as having a significant effect on the major floods and therefore were not investigated in any detail. Local effects of these reservoirs can be realized for minor storms and thus should be considered from that standpoint. Similarly, the onsite detention facilites required by ordinance for new developments in both Arvada and Jefferson County, were not analyzed nor considered in this study. I t I I I I I I I I I I Van Bibber Creek originates in the foothills of the Rocky Mountains, on Mount Tom, and flows due east for approximately 13 miles through Jefferson County to the southwest part of Arvada. At this point, the creek joins Ralston Creek, a tributary of Clear Creek and the South Platte River. Under the basin indexing system of the UD&FCD, Van Bibber Creek is designated as Basin 1-59-4306 with subbasins 01 and 02. The South Tributary to Van Bibber Creek joins the main stream near Ulysses Street and is designated as Basin 1-59-4307-01. Both basins are located in Jefferson County with the lower reaches of the main stream in the corporate limits of the City of Arvada. Drainage Basin Characteristics Sheet 1 of the drawings, Drainage Basin Boundaries, attached as a part of this report, shows the location of Van Bibber Creek relative to various landmarks of the metropolitan area. The basin is located west and south of Ralston Road and West 64th Avenue. The stream parallels 58th Street and extends west past North Table Mountain to the front range mountains of Mount Tom and Golden Peak. The total drainage area of Van Bibber Creek at the confluence with Ralston Creek is 17.52 square miles. The South Tributary basin covers approximately 2.57 square miles along approximately 3.3 miles of channel. The detailed study reach extends from the confluence with Ralston Creek to the hogback on the main stream, a channel length Crossing the basin are numerous irrigation canals. These include the Juchem Ditch, Croke Canal, Farmer's Highline Canal, Church Ditch and the South Boulder Diversion Canal. Major road crossings include Ralston Road near the mouth of Van Bibber Creek, Independence Avenue, Kipling, 58th Street, Miller, Newcomb, Oak, Ward Road, Indiana Street, McIntyre, Ulysses, West 60th, Crestone, Dunraven, Foothills Road (County Road 93)