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<br />FLOODS ,oF l'S'65 IN THE UNITED STATES
<br />
<br />SU~Y OF FLOODS
<br />
<br />E59
<br />
<br />Peak dischlU'ges in .om Canyon near Vernal (sta. 13) and in Ante-
<br />lope Creek at U.S. Highway 40 near My ton (sta.15) were gre..terthm
<br />those for" 50-year flood. The flood in Can Canyon did some damage to
<br />crops and farmland. '
<br />In south-central Utah, thunderstorms on July 25 and 31 caused
<br />floods on several streams. On July 25 a flood in I vie Creek above diver-
<br />sions near Emery (sta. 19) destroyed the crest-stage gage md caused
<br />$900 damage to fences, bridges, and irrigation-diversion structures.
<br />The peak discharge was 1.3 times that of a 50.yearflood, No precipita-
<br />tion was recorded in the vicinity.
<br />A flash flood occurred in Crescent Wash near Crescent Junction
<br />(sta. 11 'and 18) on July 31. At Thompson, 15 miles to the east, 0.60
<br />inch of rain was officially recorded ollthat day. Because of the scarcity
<br />of destructible property in the flood area, no damage was reported. The
<br />peak discharge above the detention dam was 2.7 times that of a 50-year
<br />flood,
<br />Heavy rains on July 31 also caused floods in four streams in south-
<br />central Utah. In Roads Creek at diversion near Loa (m, 20), the peak
<br />discharge was 3,5 times that of a 50-year flood. In Rabbitbrush Creek
<br />near Bicknell (sto. 21), Government Creek near Bicknell (m_ 22),
<br />and Cigarette Hollow near Teasdale (sta. 23), the peak flows were
<br />several times that of a 50-year flood. At Loa, 0.36 inch of precipitation
<br />was measured on July 31.
<br />Severe thunderstorms in central Utah on August 1 and 11 caused
<br />flash floods on several streams. On Augub"t 1 the peak discharge in Six.
<br />mile Creek near Sterling (sta. 28) was 1.6 times that of a 50-year
<br />flood. On August 1, 0,39 inch of precipitation was measured at Manti,
<br />about 5 miles to the north, but this is not indicative of the intensity
<br />of the localized storm that cause the flood on Sixmile Creek, 'On Au-
<br />gust 17 the peak flow from a 2.57-sq-mi drainage oosin in Twist Canyon
<br />near Annabella (sta. 29) was 4,930 ofs, which is 1,918 ofs per sq m!.
<br />The statistical prClba:bility of a flood of this magnitude occurring in
<br />Utah is very small.
<br />The widely scattered official rain gages did not record amounts of
<br />precipitation that had a relation to the intensity of the storm in
<br />Twist Canyon; however, 2.12 inches ot rain in 45 minutes was Wl-
<br />officially recorded at Glenwood on August 17. Approximately 2% miles
<br />of county road east of Annabella was destroyed, and gully erosion in
<br />Twist Canyon was severe.
<br />General rains over most of southern Utah on August 17 md local
<br />precipitation of cloudburst intensities caused floods in an area east
<br />of Cedar Dity.
<br />
<br />Peak discharges for four streams (sta. 30-33) are listed in down-
<br />stream order in table 21. All peak flows listed are believed to exceed
<br />those. of 50-year floods, although flood-frequency relations are un-
<br />defined for drainage areas of less than 15 sq mi in this section of Utah_
<br />Reports of precipitation at nearby Woather Bureau stations show
<br />that the rainfall varied considerably within the area. The official rec-
<br />ords a,t Cedar City FAA. Airport, Cedar City Steam Plmt, and Cedar
<br />Breaks National Monnment showed 0.04, 0.99, and 0,73 inch of pre-
<br />cipitation, respectively, on August 17.
<br />The most damaging flood was in Dry Canyon where considerable
<br />damage was done to farmlmd, industrial buildings, roads, bridges, a
<br />cemetery, a golf course and personal property. The Soil Conservation
<br />Service estinmted the total damage at $176,000_
<br />Thunderstorm activity on August 19 caused a flood in Iron Wash
<br />near Green River (sta. 16). On the same day 1.34 inches of rain was
<br />recorded at Green River, The peak discharge probably exceeds that
<br />of a 50-year flood. The rate of runoff was 112 ofs per sq mi from 179
<br />square miles. Some damage was done to State Highway 24 at the
<br />ford, but no other damage was reported 'because there are no destructi-
<br />ble structures along the wash.
<br />
<br />FLOODS OF JUNE 11 IN SANDERSON CANYON, TEX_
<br />
<br />By LEo G. STEARNS
<br />Three storms occurred in the Sanderson Canyon oosin in the vicinity
<br />of Sanderson, Texas, on June 10 and 11. The first storm occurred at
<br />about 1800-2100 hours on June 10, The times of occurrence of the
<br />other two storms cannot be readily separated in some areas. The total
<br />storm rainfall at the Weather Bureau station in Smderson on June 10
<br />and 11 was 5.35 inches, of which 1.96 inches fell between 1930 md 2030
<br />hours on Jnne 10. At the Weather Bureau recording strution 1 mile
<br />northwest of the Sanderson Post Office, 6.55 inches of rain fell on
<br />June 10 Mld 11, of which 2,24 inches fen between 1930 and 2045 hours
<br />on June 10. Total rainfan in the Sanderson Canyon basin for the storm
<br />period ranged from about 3 inches to a maximum of 9 inches. Supple-
<br />mental rainfall data, which were gathered by the Weather Bureau, the
<br />International Boundary and Water Commission, and the Corps of
<br />Engineers were used by the Corps to complete the isahyetal map of
<br />the storm (fig. 25) .
<br />Two indirect discharge measurements were made, one on Three 'Mile
<br />Draw and one on Sanderson Canyon above Three Mile Draw (iig_25).
<br />Three Mile Draw joins Sanderson Canyon just upstream from the
<br />town of Sanderson. The peak discharge from", 3&-sq-mi basin on
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