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<br />. Hydraulic Analysis.. A hydraulic: run will be completed for the five and <br />one-half mile study reach for the 5-, 10-, 50-, 100-, and 50G-year flow <br />magnitudes, These runs will use new survey information in conjunction with <br />cross sections from the Flood Insurance Studies. The water surface profile <br />wi 11 be plotted with bank or 1 evee p rofil es from both sides of the channe 1. <br />The flow magnitude where levees will be overtopped will be identified from <br />these profiles and a recurrence 'interval win be estimated from existing <br />flow frequency curves at each location, <br /> <br />. Flood Extent and Damage Review.. Where banks or levees are overtopped, the <br />extent of flooding wi 11 be mapped and proper'ties in the flooded areas wi 11 <br />be identified for increasing flow magnitudes, This information, coupled <br />with flow frequency data, will identify prior'ity areclS for improvements as <br />well as assess the need for the improvement. <br /> <br />. Improvement Plan.. The condition of existing levees will be reviewed and <br />improvements wi 11 be recommended. Proposed or improved levee systems wi 11 <br />be evaluated and design criteria established for permanent and temporary <br />facilities. Dredging of the islands immE~diately dOI~nstream of the Grand <br />Avenue bridge will be evaluated as well as any other improvements that may <br />he lp to re 1 i eve the fl ooded areas, Imp rovement pI ann i ng will cons i del' the <br />floodway on the river and the effect of improvements on the opposite side <br />of the channe 1. <br /> <br />. Flood Warning Plan - Information gathered from Federal, State, and Local <br />Agencies will be reviewed and evaluated, and a plan to best utilize this <br />information for flood warning will be established. This plan will likely <br />identify a program where the County and City contact various agencies on a <br />periodic basis to obtain the latest measured data. The data would then be <br />plotted on curves p rovi ded through th i s study to mon itor either snowfa 11, <br />snow depth, or stream gage measurements. This would then be correlated as <br />well as possible with streamflow on the river to provide warning of <br />potential high flows. <br /> <br />. Dam Failure Warning Plan - Similar'ly, information gathered from Federal, <br />State, and Local Agencies will be reviewed and assembled into a summary <br />report on dam failure and 'its impact on the Grand Junction area. Pertinent <br />information would contain a listing of th," dams, the adequacy of existing <br />spillways, the approximate effect of a failure flood wave all flow <br />discharges and flood stages at Grand Junction, approximate travel times to <br />reach the City, and a contact person fOI- each fac il ity. Some of th i s <br />information is available from the State Engineer's Office or the U,S. <br />Bureau of Reclamation. Much of the information, however, will need to be <br />approximated based upon available data. Only major dams that could have <br /> <br />:I <br />