Laserfiche WebLink
<br />FLOOD-PRONE AREAS IN ELBERT COUNTY, COLORADO--TECHNICAL ADDENDUM <br /> <br />. <br /> <br />By Theron R. Dosch <br /> <br />: <br /> <br />. <br /> <br />INTRODUCTION <br /> <br />This technical addendum is designed to supplement the report, "Flood-prone <br />areas in Elbert County, Colorado" (Dosch, 1981), that gives background Information <br />on the use of maps of flood-prone areas in Elbert County prepared by the U.S. <br />Geologica1 Survey in cooperation with the Elbert County Board of Commissioners and <br />the Colorado Water Conservation Board. The addendum contains all of the cross- <br />section data used to construct the maps and a detailed discussion of the methods <br />used to determine the hydraulic properties of the stream at each surveyed cross <br />'section. Forty-nine maps have been produced to date (November 1981) of an area in <br />Elbert County that includes the West Bijou Creek basin and all basins west to the <br />Elbert County-Douglas County line. <br /> <br />Computer printouts of card images, topographi~ maps, and aerial photographs <br />constitute the basic data for the project. Card-image printouts of the data used <br />by a computer program to calculate the hydraulic properties of the stream at each <br />cross section preserve the surveying notes in a compact, easily readable form. <br />The initial 69 cross-section surveys were made by U.S. Geologica.l Survey personnel <br />in 1979; cross sections numbered 70-93 were surveyed by personnel of the Colorado <br />Water Conservation Board, the Kiowa Soil Conservation Service District, and Elbert <br />County during 1980. <br /> <br />Topographic maps, 7.5-minute series, prepared by the U.S. Geological Survey <br />during 1955-70, were enlarged to a scale of 1 in. equals 1,000 ft before flood- <br />plain boundaries were added. Aerial photographs were taken by the Agricultural <br />Stabilization and Conservation Service of the U.S. Department of Agricuiture in <br />1977. Enlarged prints from those aerial photographs were purchased with project <br />funds and provided to the Elbert County Land Use Administrator. The photographs, <br />at a scale of 1 In. equals 1,320 ft, correspond fairly closely in size with the <br />flood-plain maps so that familiar landmarks, such as trees, new roads, oil tanks, <br />and contoured ditches enable the layman to orient himself with respect to features <br />shown on standard maps. <br /> <br />. <br /> <br />, <br /> <br />The original cross-section survey notes and the topographic maps used for <br />enlargement are in the U.S. Geological Survey files. The notes and maps may be <br />examined by contacting the District Chief, U.S. Geological Survey, Mail Stop 415, <br />Box 25046, Denver Federal Center, Lakewood, CO 80225. The enlarged aerial photo- <br />graphs may be inspected at the office of the tlbert County Land Use Administrator, <br />County Courthouse, Kiowa, CO 80117. <br /> <br />1 <br />