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<br />West Branch of Salt Fork Dredged Channel near Urbana, illinois, Approximate
<br />bottom width 20 feet. Picture taken July 1924,
<br />
<br />
<br />I Date of obser. A\'cr. Aver- Aver- Menn leoem_
<br />..' su~:oo Dl~ ,go Mean hy- Slope of cientof
<br />I "stieD mali- charge ""'" veloc. draulic water rough- Description of channel
<br /> mum width section Ity radius surface n",
<br /> depth n
<br /> ---.---
<br /> May 1,1924 ~7 29.2 148.4 57.0 ." 1.84 O. 000844 0.020 Cburst, straight; 480 feet long. Cr068 8taion, very little variation in shape;
<br /> ~r. 26,192( ~. 30.6 151.2 .... 2.31 2.01 . 000898 .030 for variation 10 size, see fig. 20, C. Side slopts, fairly regular. Bottom,
<br /> at.20,192S 3.. 31l.5 286.1 91..'i 3.13 2.42 .000Il33 .026 quite flat but somewhat Irregular In places. Soil, bottom covered with
<br /> Feb. 9,1925 '.1 39.4 301.1 11)'-7 2.8.> 2.53 .001085 .031 stones and gravel; upper ~8rt, bowlder clay with oxldlted Iron. Condi-
<br /> Mar. 19,1925 ... '" 481.5 141.' 3.41 ~.3 . 000806 .02' lion, some small sprouts, ushes and dead grass on side slopes, without
<br /> Mar. U, 1925 '.3 47.7 483.1 161.7 2." 3.20 .00074.4. .029 follsge; bottom covered with mossy stones at lower end of course, but
<br /> Apr. 8.1926 '-' 49.8 666.7 185.3 3.60 3.62 .000908 .030 mostly .with gravel at upper end. Comtruded, about 19()11 (PI. 24, B
<br /> Feb. 25,1926 ,. 49.8 6"-0 186.2 3.36 3.53 . 0006M .030 aDd fig. 19, C.)
<br /> Doc. 19,1924 6.1 61.0 ....7 201.3 3." 3.72 . 000704 .037
<br /> h_..do._hnn .6 53.' '06.4 237.1 ..0 4.14 .000704 .030
<br /> Apr. 7,HI26 .., 63.6 1,402.0 392.5 U7 5.71 .(')0'" .032
<br />
<br />Monona-Harrison Dredged Channel near Onawa, Iowa. Approximate bottom width
<br />20 feet. Picture taken in 1916,
<br />
<br />
<br />I Date of obser.
<br />I vatloD
<br />I
<br />
<br />Coeffi-
<br />dent of
<br />rough-
<br />n'"
<br />n
<br />
<br />; Aver-
<br />su~:ce
<br />.....idtb
<br />
<br />Aver.
<br />..'
<br />maxi.
<br />mum
<br />depth
<br />
<br />Mean
<br />hy-
<br />draulic
<br />radius
<br />
<br />Aver.
<br />,g,
<br />"'''''
<br />ooction
<br />
<br />Sloponl
<br />w.'"
<br />surface
<br />
<br />Moan
<br />veloc-
<br />Ity
<br />
<br />Description of channel
<br />
<br />n...
<br />charge
<br />
<br />--. --------
<br />
<br />Cour,(', straight; 948 feet lon~. CrO/l' ,utioR, slight variations in shape.
<br />abrupt variatIons in size. Sid(' ,~tI, Quite irregular, particularly UPpal'
<br />part. Bottom, fairly regular. Soil, dark silty loam. Condition, con-
<br />siderable growth in upper portion of channel, none in lower; silty material
<br />deposited. on bed and sides of channel. Comtnu:Ud, 1910. (PI. 13, A and
<br />fig. 8, E.
<br />
<br />lune 2,1916
<br />May 22,1916
<br />
<br />37,2 221.0 131.3 1.68 2.60 0.000267
<br />m~~:~l"~~~:O- ..~~:8_ __~_~_ ___~:~._ ..:~~- .
<br />
<br />0.027
<br />.O2l'
<br />
<br />...
<br />6..
<br />110.0
<br />
<br />I-~~~--~~~~!-I
<br />
<br />8.5"\69.8\ 499.0 1308.0 11.621 4.82, I 0.000178 0.0361 Practically no change in cbannelsince measurements were made in 1916.
<br />8.8 61.5 M6.S 322.1 1.70 4.92" .0001475 .032 .
<br />110.0 nnn._ un__.___ un_on n._." _nnnO ~..n...__ nO..n_
<br />
<br />I Average maximum depth at bankful stage.
<br />
<br />Sides of channel slightly coated with mud. Bed and flat portions of the channel sides
<br />was coated with silt.
<br />
<br />13
<br />
<br />
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