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<br />Allen Creek Dredged Channel near Mis souri Valley, Iowa. Approximate bottom <br />width 15 feet. Picture taken 1917 . <br /> <br /> <br /> Aver- Aver- Aver- Moan Coeffi. <br />Dateofobser- '.' ,.' D". '.' Moan hy. Slopeo! elentof <br />vation maxi- surface ,"u.. """ veloc- draulJo water rough. <br />mum ity surlaoo n.. <br /> depth width section radius . <br /> --- <br /> <br />June 4,1917 <br />__...do___..._ <br /> <br />Description of channel <br /> <br />Feet <br />7.1 <br />7.16 <br />'&00 <br /> <br />p,,, <br />42.3 <br />42.4 <br /> <br />Second- <br />rut <br />tlao.8 <br />837.1 <br /> <br />Ft. per <br />ItC. <br />4.n <br />4.24 <br /> <br />0.014 <br />.014 <br /> <br />Coura', straight; 794 feet long. CraM aectltml practically no variation In <br />sbapej for variation In size, see fig. g, A. Siae ,lopttl, smooth and I"elrnlar. <br />Bottom, even and r~ar. Soil, heavy, dark, silty loam. Condition, <br />practically no vegetatIon in channel; bottom covered with ~ to 1 foot of <br />mud; sides covered with slit of slimy and slippery nature wblch was no <br />doubt prinCipally responsible for low value of n. Con&trudtd, summer of <br />1916. (Pl. 11, A and fig. 8, A.) <br /> <br />p,,, <br />4. 30 . 0002897 <br />4. 32 . 0002392 <br /> <br />&i. fl. <br />196.2 <br />197.4 <br /> <br />..........'........--.............---......----.....1..------ <br /> <br />I A V'lrag6 madmum depth at bankful stage, <br /> <br />The perimeter of the channel was coated with slippery mud, <br /> <br />Pigeon Creek Dredged Channel near Cresent, Iowa, Approximate bottom width <br />15 feet. Picture taken in 1917 . <br /> <br />I Dateofobser- <br />vatlOG <br /> <br />June 6,1917 11.7 <br />112.0 <br />"juDsne:i9ii" 12.4 <br /> <br /> <br />Aver- <br />... <br />marl. <br />mum <br />depth <br /> <br />A -=JA M" c..m. <br />ver- ver- Mean oon Slope of ciant of <br />age Dls- age hy- h <br />surface charge cross vetoo- draullc water fOug. <br />width section fty radlU8 surface n:s <br />- - <br />48. 6 1,685. 1 329.8 5. 11 6. 18 0.600642 0.025 <br />-"63~8" n2,"047:i- --863:7- -Ti3- mti:i2- --:OOOO2i- m:022- <br /> <br />Course, su-slght; 858 feet long. OM3 ,ection, sIlght variation in sbape; for <br />variation in size, see fig. 9, D. Side 8WpelJ, left side falrlr. regular; right <br />side rough and irre~ular. Bottom, slightly Irregular. Soil, heavy. dark <br />silty loam. CofldltJO'1l, very little vegetatIon In chimnel. bottom covered <br />with ~ to 1 foot of mud; sides coated with slippery silt. C'o111tructed, <br />1907. (PI. 12, A and Fil,t. 8. D.) <br /> <br />Description of channel <br /> <br />I J.. verege maximum depth at bankful stage. <br /> <br />