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a. Develop HEC -RAS models as noted in the Halff proposal and per the watershed <br />map <br />b. Develop floodplain boundaries for the 10 -, 25 -, and 100 -year storms for the <br />existing and fully developed watershed conditions for all studied creeks. <br />c. Develop profiles for the design storms identified in (4.b) above. <br />d. Identify flood -prone areas on maps. <br />e. Meet with City staff to review preliminary findings /gain their input on historical <br />flooding <br />f. Review existing Community Rating System (CRS) and evaluate opportunities to <br />expand program to benefit local flood insurance rates <br />g. Perform field verification of flood -prone areas and correspond with City staff <br />h. Perform field survey as needed to further define flood -prone areas and impacts. <br />i. Identify flood -prone structures and summarize level of flooding, for example, a <br />table will be prepared that lists structure, storm event to initiate flooding, depth of <br />flooding, etc. <br />j. Assess floodplain management structural solutions, prepare conceptual designs, <br />and develop construction cost estimates. Consider creek erosion findings in this <br />process. <br />k. Review technical memo summarizing floodplain findings, areas of impact, level of <br />severity, costs, potential project needs and CRS benefits. Will be used in the <br />solution development task. <br />5. Storm drain system analysis (localized flooding for identified /known problem areas, see <br />RPS Espey Attachment 1, 27 identified areas) <br />a. Collect existing models from the City if available <br />b. Coordinate with City staff to review complaints (City provided 25 locations), <br />perform field investigation <br />c. Assess storm drain function with StormCad for the 25 -year design storm (after <br />floodplain delineation), will use Rational method to analyze 2 -, 10 -, and 25 -year <br />storms to evaluate flooding frequency <br />d. Field investigation, map problem areas, delineate findings <br />e. Visit with City staff, confirm findings with historical data <br />f. Develop conceptual design solutions to manage 25 -year storm if possible, if not, <br />achieve 10 -year storm protection. <br />g. Prepare construction cost estimates <br />h. Prioritize storm drain project solutions <br />i. Prepare technical memo summarizing findings /recommendations <br />6. Creek erosion assessment and project solutions (benefit of this task is early detection of <br />potential problems to avoid future large project costs) <br />a. Review City data /reports related to creek erosion <br />b. Perform creek and river review /note problem areas, staff invited to participate <br />c. Identify potential threats to bridges, utilities, buildings, homes, parkland <br />d. Estimate potential creek channel enlargement and impacts <br />e. Map existing problem areas and projected future threatened creek segments <br />f. Visit with City, share update on creek erosion findings <br />g. Prepare conceptual designs and construction cost estimates for problem areas <br />h. Prioritize erosion management projects <br />