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<br />Table <I <br />100-Year Flood Water Surface Elevations <br />with Improved Levee and W,~s't Levee Extension, <br />Part of Existing Levee Removed <br />(No Levee Condition is Restored FIS File) <br /> <br />Cross section <br /> <br />Computed 100-Year Water Surface <br />Elevatil)n~~n feet m.s.l.) <br />with Leve~ No Levee <br /> <br />33.2 <br />36.C <br />37.C <br />38.( <br />39.( <br />40. ( <br />41. ( <br />42.( <br />43.( <br />44. (, <br />45. (, <br />46. (, <br />47. (, <br /> <br />5204.59 <br />5205.57 <br />5205.7!5 <br />5206.06 <br />5207.63 <br />5209.09 <br />5210.34 <br />5211.75 <br />5213.07 <br />5214.28 <br />5215.68 <br />5218.35 <br />5219.34 <br /> <br />5204.59 <br />5205.57 <br />5205.75 <br />5206.06 <br />5207.63 <br />5209.08 <br />5210.32 <br />5211.73 <br />5212.97 <br />5214.13 <br />5215.70 <br />5218.34 <br />5219.34 <br /> <br />Ti,e top-of-Ievee ele,vatiems det,ermined for this study are <br />based on a preliminary level of analysis. The top-elf-levee <br />elevations for a final design should be based on the chosen final <br />levee alignment and the changes in .topography due to 1:he levee <br />constr~lction . <br /> <br />In the reach along the poten1:ial west levee, the 500-year <br />flood .'ater surface eleva1:ions wit,h the levee considered in place <br />were approximately 1.7 feet higher than the 100-year flood Ylater <br />surface, elevations. This shows tha.t the 500-year flood event could <br />be con1:ained in the 3-foot freeboard zone of a levee wi.th a 100- <br />year level of protection, but the le!vee would not be considE~red to <br />provide, that 500-year flood protection. <br /> <br />Effect of Levees on Floodwav <br /> <br />Wilen the existing le,vee syst.em wa.s extended to its present <br />length, approximately 300 feet at 1:he north end of the levee was <br />locatecl in the floodway delineated for the FIS. If this levee were <br />assumecl to be effective, t.he floodway would have to be adjusted in <br />t:his location. The HEC-2 model with the existing levee was <br />adjuste,d at cross section 42 so that the left-bank floodwdY limit <br /> <br />11 <br />