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<br />. <br /> <br />. <br /> <br />. <br /> <br />IX. CONCLUSIONS <br /> <br />Presented in Table-4 and -5 are the final revised 100-year floodplain and floodway data as detailed <br />in this report, At Section 15.0 the rise in water surface elevation with the floodway is 1.1 feet. This Section <br />is unchanged from the existing model. Therefore, the existing model was re-run using a current version HEC- <br />2, The rise in water surface elevation in the existing model is also 1.1 feet, compared to 1.0 feet in the <br />previous study, It is our opinion that the different rise in water surface elevation may be the result of different <br />algorithms in the two different versions of the HEC-2 programs, This revised floodplain is graphically <br />represented on Figure-4 with the profile on Figure-5, A computer diskette (5',4 ", 1.2M Floppy) and <br />description of the HEC-2 computer files are included in Appendix J, <br /> <br />Interior drainage from runoff generated within the Town was analyzed and master planned in a 1989 <br />report titled "Town of Erie, Master Drainage Study" (Reference 7), Outfalls from the Town to Coal Creek <br />are planned at Moffatt Street, Wells Street, Chessman Street. Evans Street. and Balcolm Street. Only the <br />Evans Street outfall penetrates the proposed levee and will be included in the proposed construction, The <br />outfall will be constructed with a flapgate to prevent 100-year Coal Creek flows from entering the Town, <br /> <br />The proposed improvements will remove the Town of Erie from the 100-year floodplain as well as <br />reducing the flooding potential of the 500-year flood flows, The improved Perry Street bridge and Union <br />Pacific Railroad Bridge will pass the 100-year Hood without overtopping of the roadway or railroad. These <br />improvements also allow for potential channel and/or floodplain improvements to occur upstream of Perry <br />Street without further downstream improvements, Containment of the 100-year Hood will greatly decrease <br />the damage potential and the cost of such damages in the improved reaches, The Town will also obtain <br />additional protection from 500-year Coal Creek flows, <br /> <br />The proposed improvements maintain or reduce the 100-year water surface at all locations, The area <br />upstream of the project is currently undeveloped and thus the proposed improvements will allow the full <br />development of the upstream property upon completion of any necessary upstream improvements, Thus, the <br />improvements will not only benefit the Town of Erie but future developers of adjacent properties, <br /> <br />7 <br />