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<br />" <br /> <br />function .03 d concrete-lined channel passing flow from the two culverts to a <br />Thompson and Platte Ditch crossing dnd into the Great ~eatern Railroad pond. <br />Alternative 85 would follow the sams path out of the fire station pond as <br />Alternative 52. The flow would be directed west along the south sIde of <br />llighway 60 to the Thompson and Platte Ditch then <lo.." tha ditch to th" Great <br />western Railroad pond as shown 1n Figure 25. Flood waters would be routed <br />"est out of the fire station pond under Josephine Avenue and Broad Street via <br />four 42-100h reinforced concrete culverts. The Bouth ditch adjacent to <br />llighway 60 would be recontoured to improve flow to the Thompson and pl"tte <br />Ditch. Storm runoff would carry into the Thoapson and Platte Ditch and flow <br />und.", 1I1ghway 60 "ndback eastward to the La.nra lIvenue right-of-way ",here <br />discharge in exceS$of normal ditch capacityw<>uld spill into the Great <br />Western Railroad pond. <br /> <br />E:astern Flow path <br />The solution to the flooding problem in the east is not as simple as <br />releasing flow fro= the ponded area as fast as it enters. Drainage capacity <br />drn.-nstreamislimitedtol00cfsduetoMlrrowr1ghts_ot_wayandtlatslopes. <br />aoth structural improvement options include a detention/sedimentation pond <br />with controlled release south of the Union Pacific Railroad emban~nt and <br />west of County Ro"d 23. Hgure 24 shows an E:aatern Flow path 1I1ternative 4. <br />'l'hi$ alternative is identical to "lternative 2. Itwasshowntwicer.olndi- <br />cate hO>l an enlarged Union P"cific detention pond (LOla Par~ Trib<>tary <br />Alternative All could drain. <br />"lternative 2 (Figure 22) releases flood ",ater from the pond via two <br />42-inch reinforced concrete culverta jacked through the Union pacific Railroad <br />embankment. These drain into a short open channel leading to County ROad 23. <br />Here a 42-inch corrugated metal pipe (CMP) positioned diagonally under the <br />..""'" "",,,11 tran"",it ro"shlj' h",~! of t..'>" Cc~ign ct.."'h"-rgc to to'";c c.>.~t .lltch. <br />Ditches on both sld~s of Co~nty Road 23 would ~ improved to a ca~acity of 50 <br />cis eaCh. The east ditch would extend from the end of the 42_inch corrugated <br />metal pipe to Eighw~y 60. The weat ditch undermine~ an Obstructing drive",ay <br />in a 42.inch corrugated metal pipe an~ ccntinue~ ~rth to a point '50 feet <br />south of Eighway 60. He..e a 48-inch corrugated metal culvert picks up the <br />now and run.. di"gonally northwest to where the east ditchll\eet the highway, <br />TwO 48-inch reinforced concrete pipes jacked under Highway 60 wo~ld carry the <br />