Laserfiche WebLink
<br />II <br />II <br />. <br />II <br /> <br />lSOi <br /> <br />During the first stage of the present study the historic flow data for the Arkansas River <br />above John Martin Own were evaluBted. This historic information waB obtained from the United <br />States Geologic Survey's (USGS) web site and imported into a spreadsheet program. The data <br />set covers the period from 1903 through 1999, although the data have been gathered from five <br />separate gage locations over that time. <br /> <br /> <br />The study area includes an approximately gO-mile reach of the Arkansas River from just <br />downstream of Pueblo Dam. near Avondale to just upstream of John Martin Reservoir near Las <br />Animas, Colomdo. Five gages will be studied which Include; three stream gages owned by the State <br />Bnd two U.S. Geological Survey (USGS) stream gages. These are listed in Table 3.1. <br /> <br />~ <br />I <br />~ <br /> <br /> TABLE 3.1 <br />STREAM GAGES <br /> , <br />Gage Name Gage , Drainage Area Gage Period <br /> Number (Square Miles) Elevation (fl) Of Record <br />Arkansas River near Avondale. CO 07109500 6327 4510 193910 51, <br /> 65-1999 <br />Arkansas River near Nepesla, CO 07117000 9345 43g5 1903,12, 14- <br /> 1999 <br />Arkansas River at CaUin Dam near Fowler, CO 07119700 10901 4246 1965 to <br /> . 1999 <br />Arkansas River at La Junta. CO 07123000: 12210 4040 1894,1903, <br /> 12 to 1999 <br />Arkansas River at Las Animaa, CO 07124000 13976 3884 1921-72 <br /> 1974-99 <br /> <br /> <br />A Discharge Ra1ing Curve was developed for the La)unta stream gage at the request of the <br />CWCB (Referto Plate 1). <br /> <br />The Albuquerque District investigated discharge-frequency relationships for the stream <br />gages on the Arkansas River from just downstream of Pueblo Dam. near Avondale to just <br />upstream of John Martin Reservoir near Las Animas, Colorado. <br /> <br />The current study utilizes data from an earlier Corps of Engineers flood control study by <br />reducing the actual flow by a percentage due to the ~ssumption that Pueblo Dam was operating <br />prior to 1975. The 1967 Hydrology DM #1, developed for the Las Animas Local Protection <br />Program. Table 13, page 22. used data from the Las Animas stream gage to describe existing <br />conditions preceding the construction of Pueblo Dam in 1975. We compared the flows at the <br />other four stream gages and interpolated based on the percentage of decrease in flows for each <br />year. The adjusted data were placed into an Excel spreadsheet and incorporated into an input file <br />for the Flood Frequency Analysis (FFA) program. The Corps then performed a Log-Pearson <br /> <br />26 <br /> <br />3 <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />1 <br />I <br />'1' <br />I <br />1 <br />I <br />1 <br />I <br />I <br /> <br />