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I I I I I I I I I I I '. I I I I . I I ". "n" VP,L1IE AWILYSIS The flannings roughness coefficient, "n", is a value used to estimate the resistance of flOl'1 in a given channel or overbank. This villue is estil:Jitted by the engineer using published information together I~ith his experience and judgelllen~ of field condi tions. f'ublislHJd lubles ill''" i1vaililble lIwt show typical "n" 1ialues for certain channel and overbank conditions, and these tables are sU[lplemented with photographs (Reference?). IJsin'l these tables and the engineer's KJowledge of the exist.in,! flood p'lain, "n" values wer" chosen for the vario~s reaches along Spring Creek. Spring Creek chosen based ~/as divided into 21 separate l'e,lches. These reaches \Vel'e upon varying land characteristics and uses that affect t.he flood lllain rOIJ~hrless. ~ The "n" values established in this report I,Jill be used 'in Olll' Hydl'aulic Analysis of Spring Creek. For this analysis, the U, S. AI'my Corps of En~lineers /lEC-II computer program will be used to compute Hater Surface Profiles (Reference 3). This pro')ralll divides the flood plain into the channel and left and right overbank areas. Therefore, "n" values were identified for these portions of the cross section. Fi~ure I shows a typical channel cross section defining these areas as they will be used in Ollr hydl'aul ic analysis. Included in the appendix is an Index Map that shows the location of each reach identified in this report (Figure II). Follo~Jing the index milp are photographs, reach descriptions and estil"ill(~d "n" v,\lll"s for "itch ~'('~,:h along the stream, Also included is a SlIlIhllary lilllle of "n" valllrs (Tallle 1) along l'lith "n" value refer'ence tables. AftPI' the cross s'?ctions have been established for tlte Itydl'aulics calculdtioll'; in Lhis sLlIdy, d tdble \'Iill I)(~ asselllllled identi fyin,! the cross sectioll~, \'Ii I.hin e,1<:1] rf?itch. Thh tJIJle ~Ii 11 be Jdded to thi s rer'Ol'l a tal il ter da le. Prepa red by: If} -e..o 11. # j/i..~ , -~--r~nTial:ls-------------" .. 0v1tJ.? IfWk~- --.l;l;rTcf'r:--r1ijTh.lf~):- r:----.- -- Reviel'!ed by: