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<br />critical. The effects of brj.dges, cuJ_ve.~t.s, weirs and dams can be con- <br /> <br /> <br />sidered in the computations. The procedure used is similar to Method I, <br /> <br /> <br />Back.ater Curves in River Channels, Engineering Manual 1110-2-]l.09, USCL <br /> <br />This method applies the Bernoulli Equation for totaL energy at each <br /> <br /> <br />chanael cross section and Manning's formllla for friction head loss be- <br /> <br /> <br />tweerr cross sections. <br /> <br />The final water surface profile and 100-year flood plain shown on <br /> <br /> <br />the jrawings "as computed utilizing the m:C-II program. <br /> <br />lOO-Ye~~Floodway <br /> <br />The lOO-year floodway was determioed using the criteria devel- <br />oped by the U:cban Drainage and Flood Con1:rol DistricL The Flood Regu.. <br />latory District covers the lOO-year flood plain, This District was di.. <br />vided into the Floodway District and the Flood Storage District in such <br />a ma:1ner that encroachments will be alloHed into the flood plain, i. e. 1 <br />Flood Storage District, from either side without causing U,e lOO-year <br />floo,j water surface elevation to rise more than 0.5 foot above t.hat. for <br />the :olood Regulatory DistricL Table II ,cS I ists the necessary data to <br />establish the limits of the Floodway District from the centerline of the <br />channel. Left and right limits are defined in relation to the center- <br />line of the channel by looking at. the re~:pective cross sect.ions in an <br />upstceam directionc <br /> <br />Encroachment stations were determined such that. each modified <br /> <br /> <br />eras:; section will have t.he same dischar~:e carrying capacity as the <br /> <br />exis1:ing cross section. To compute the f~nc:coachrnent limits, Met.hod l. <br /> <br /> <br />specified in the HEC-II computer program wa:; used. <br /> <br />IT--] <br />