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<br />20 <br /> <br />FLOODS OF SEPT. 1970 IN ARIZ., UTAH, COLa.. AND N. MEX. <br /> <br />CENTRAL ARIZONA <br /> <br />2 <br /> <br />35' <br /> <br />" <br /> <br />DI'IA'NAGE A"'EA, tN SQlJAI'IE KlLOMETEAI <br />lOCI 1000 <br /> <br />""" <br /> <br />" <br /> <br /> <br />112' <br /> <br />1ll" <br /> <br />." <br /> <br />~ <br />~~.. <br />"'I(~ <br /> <br />I <br /> <br /> <br />, <br />..ell 100 l <br />:1 <br />I <br />I <br />i <br />\ <br />I <br />" <br /> <br />o..~ <br />~08 ""0 <br />00 <br />~l'~lO <(0", <br /> <br />~ <br />~ \00 <br />. <br />! <br />o <br />~ <br />~ <br />~ <br />, <br />... 10 <br />I <br /> <br />" <br /> <br />,~ <br /> <br />" ! <br />I <br />I <br />; <br />il <br />I <br />, <br />, <br />i <br />1 <br /> <br />. <br />~ <br /> <br />EX'LANATlON <br />.hFloodolSapW_11J70lnoontteIAtIZ<l",. <br />N""'l>et..l.R1O'"'1....llIt~norml_l. <br />1._..110 I_UII.7 and Wb..lIl <br />o 'loodllriO-r.oll70tllltl\od.dlodw'gl <br />.......'ttHln2,OOOti......lNtQU........., <br />of ""''''.lnago.... <br /> <br />'" <br />DRAINAGE ...RE.... IN SQUARE MILES <br /> <br />10,000 <br /> <br />FIGURE S.-Maximum discharges in relation to drainage areas in Arizona. <br /> <br />Salt <br /> <br />o <br />I' ,", " <br />o <br /> <br />25MLES <br />, <br />2<:.KlOMETERS <br /> <br />camps away from the banks. Between 1530 and 1600 hours, the creek <br />suddenly rose several feet and became a churning mass of water, rocks, and <br />mature pine trees, The flood took the lives of 15 persons; 14 people drowned <br />along Tonto Creek and one along Christopher Creek when housetrailers, <br />campers, and automobiles were swept away and cabins were washed off their <br />foundations and destroyed, Several hundred persons were stranded in the <br />Payson area when roads and bridges were washed out. The electricity was <br />cut off in some areas when powerline poles were washed away. <br />Most of the flow in the upper part ofTonto Creek basin originated on the <br />north and east sides of the amphitheater at the head of Tonto and Dick <br />Williams Creeks. High-velocity flows moved 8-ft-diameter (2.4-m-diameter) I <br />boulders and large ponderosa pine trees, which formed large jams. The flood <br />destroyed Tonto Spring on Tonto Creek and deposited debris in ponds at the 1 <br />State fish hatchery, which caused the loss ono,ooo Ib (32,000 kg) offish. The <br />flood washed out a small dam near the fish hatchery, and 4-5 ft (1.2-1.5 m) of <br />downcutting and about 100 ft (30 m) of lateral erosion occurred in about <br />1-1/2 hours and endangered residences at the hatchery. <br />The channel of Dick Williams Creek was scarred by the flood to within <br />600 ft (180 m) of the top of the Mogollon Rim (1. W. Smith, U.S. GeOlogical <br />Survey, oral commun., 1970), where log jams impounded much detritus. <br />Torrents of water, rock, and debris were released when the jams broke. The <br />sudden releases probably caused the severe erosion along the channel and <br />the formation of a mudflow after the peak. In the lowermost one-fourth mi <br />(0.4 km) of Dick Williams Creek the entire perimeter of the channel was <br /> <br />:~~:;N~~":lJ~tjJo...~~L:;~~CAL SURVEY EXPLANATION <br />~09 STREAMFLOW-GAGING STATlON- d26 <br />Numbltr conesponds to that in table <br />6 and In station data <br /> <br />MISCELLANEOUS STREAMFLOW- <br />MEASURING SITE-Number <br />corresponds to tbat in table 6 <br />and in station data <br /> <br />FIGURE 7.-Location of t1ood-determination sites in central Arizona. <br /> <br />small headwater tributaries reached the main channel at nearly the same <br />time. The peaks were of sufficient magnitude to produce high flows many <br />miles downstream; the peak discharges generally decreased in a downstream <br />direction unless supplemented by flow from additional tributaries draining <br />areas of high-intensity rainfall. <br /> <br />TaNTO CREEK BASIN <br />The most destructive flood of the Labor Day weekend occurred in the <br />Tonto Creek basin. The upper part of the basin is a popular recreational <br />area, where pleasant streams drain the pine-covered mountains below the <br />Mogollon Rim. Tonto Creek began rising on September 5, and Forest <br />Rangers began assisting people in crossing the swollen stream and in moving <br />