Laserfiche WebLink
<br />f <br />~ <br /> <br />FLOOD SITUATION <br /> <br />SOURCES OF DATA AND RECORDS <br /> <br />i <br /> <br />, <br /> <br />Information relative to past floods was developed from available <br />streamflow and precipitation records, from Interviews with local resi- <br />dents, from research of newspaper files and historical documents, and <br />from reports of other Federal agencies. Basic hydrologic data were <br />derived from streamflow records of the stations shown In Table 1 (pag~ <br />6). The gaging stations are shown on Plate 2. <br /> <br />The maps prepared for this report were based on U.S. Geological Survey <br />7.5-mlnute quadrangle sheets entitled "Colorado National Monument", <br />"Grand Junction", and "Clifton", editions of 1962. Cross sections and <br />stream profiles were developed from large scale topographic maps prepared <br />in 1966 and furnished by the Western Colorado Regional Planning Commission. <br />Structural data on bridges were obtained from Mesa County, the Colorado <br />Department of HI~lhways, and the Denver and Rio Grande Western Railroad; <br />and by Corps of Engineers personnel during the course of the study. <br /> <br />FLOOD SEASON AND FLOOD CHARACTERISTICS <br /> <br />Floods around Grand Junction usually occur In April, May, and June <br />from rapid melting of the mountain snowpack, occasionally augmented by <br />rain. Thunderstorms, that may be accompanied by intense rainfal I, can <br />occur In the region from late May through September; however, runoff from <br />such storms has little effect on streams as large as the Colorado and <br />Gunnison Rivers In the Grand Junction area. <br /> <br />FACTORS AFFECTING FLOODIilG AND ITS It1PACT <br /> <br />Obstructions to Floodflows - There are five bridges crossing the Colorado <br /> <br /> <br />River and one crossing the Gunnison River In the study area. None cause <br /> <br />~ <br />l <br />I <br /> <br />5 <br />