FLOOD05505 - Laserfiche WebLink

Home Browse Search

TABLE 4 HYDROLOGIC ANALYSIS AND HYDRAULIC DETER.'lINATIONS STREAMFLOW MEASURI~C STATIONS Flood Characteristics Floodflo~s on the Gunnison River and Tomichi Creek occur consistently during the snowmelt period (April-June) and are occassion- ally augmented by rain. During this period, the precipitation is ~en- erally observed to be low at most weather stations in the basin. The period of cloudbursts activities oCCur during the summer months after the high runoff has receded. These Bttivities are normally localized and, therefore, do not produce high flowa in the strenm~. Runoff Ga~1ng Station Beaver Creek at Hierro Blue Mesa Re~ervolr near $npinero Caatle Creek near Baldwin Cebolls Creek near Lake City CebollaCreckatPowderhorn Cement Craek near Created Butte Cimarron River at Cimarron Hydrologic Analysis The hydrologic analysis establIshed the peak discharge_fre_ quency relationships for floods of 10-, 50-, 100- and 500-year recur- rence intervals for both Gunnison River and Tomichi Creek. Streamflo~ data for 51 measuring stations located .rfthin t.h~_ r,"nni~on hasin and in th~ nearby basins ~ere u~ed in this analysis. A list of these stations with their respective drainage nreas and period of recorded peak flows is ~h""", in Tablc 4. The source of this d.Ha is the official u.s. Cimarron River near Cimarron Cimarron Creek belo~ Squa~ Creek Coal Creek near Crested Butte Cochetopa Creek near Parlin Curecanti Creek near Sapinero East River at Almont Geoiogical Survey ~ater supply papers. A number 01 correlations bet~een historical streamflow records of different gaging stations ~ere con- ducted. rhose correlations with a high coefficient of correlation were used to extend the historical recorded data. The recorded and extended data ~a8 utilized in frequency analySis to determine flows for the 10-, 50-,100-, and 500-year frequ"nc1es at r"spe.cti..." locaUtm". All cumu- lative frequency distributions ~ere performed utilizing the Log Pearson East River below Cement Creek East River near Crested Butte Goose Creek at Wagon~heel Cap Gunnison River below Slue Mesa Gunnison River near Cimarron Gunnison River near Gunnison Type III l'!::t~od, ,,:: s'-'ggcstcd by thc U"it"O: $t.;~,,~ '.;..~"r ""buu'e"" ~unnlson Kiver belo~ ~unnison Tunnal Council Bulletin Number 15, "A Uniform Technique for Determining Fiood Fl"" Frequencies". A summary of the reBults of thi~ .,nalysi6 is 6hOWIl in Tabl..S. Gunnison River at 101a Henson Cr..ek at Lake City Oischarges for tbe 500.yoar (1000],; r'>r ,,11 SCresms ..ere deter- mined utilizing both the lOR-Pearson Type IlL Method and the stralght- line extr~polat10n of ~ semi-log plot of flOQd dltichar~es computed for freque"cl.." up to 100 years. Results obtain..d from Log-Pearson wcre used for desi~n discharges. Lake Fork at Gatcvic" n 16 Orai"age Area (sq.m!.) PerIod of Recordod Peak F10~ 36.0 3,426.0 17.5 25.5 334.0 27.7 212.0 1940 1965 1945 1948 1938 1940 1940 1962 1955 1943 1942 1940 1951 65.0 232.0 8,' 346.0 31.8 289.0 1913, 1918 1935 1964 1940 1955 1953 1904 1912 1916 1945 1<;06 1900 1938 1918 1929, 191;' ;']5.0 89.;' 90.0 3,453.0 3,650.0 1,012.0 J, ~lJ~. V 2,490.0 &2.0 334.0 1943 Date 1950 1954 1955 1951 1905; 1967 Date 1952 1946 1948 1972 1916 1921, Date 1972 1951 Date 1968 1905 1914; 1928; 1974 D,ne 1903; 1951 1919, 19:18-nate 1937