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<br />This report was prepared under the supervision and direction
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<br />undersigned, whose seal as a professional engineer is affixed.
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<br />EXECUTIVE SUMMARY
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<br />The City of Greeley (City) retained the engineering firm of Simons,
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<br />Li & Associates, Inc. (SLA) to conduct a master floodway plan for ~le reach of
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<br />the Cache la Poudre River within the City. The purpose of the master floodway
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<br />plan is to assist local officials in planning and regulation of the Cache la
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<br />Poudre floodplain and to minimize flooding problems within the City. The City
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<br />formed a Floodplain Panel to investigate the needs regarding the floodplain
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<br />and to p~ovide direction to the engineering consultant~
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<br />Introduction
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<br />Wen-Sheng L
<br />Vice President
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<br />Scope of Work
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<br />This study includes descriptions of the study area, hydraulic analysis
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<br />including verification of the flood insurance stUdy results, erosion and
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<br />sedimentation analysis, development of alternatives to reduce flooding
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<br />problems, evaluation of alternatives, and preliminary design of the recom-
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<br />mended alternative.
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<br />Hydraulic Analysis
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<br />Hydraulic analyses were performed to verify ~le results of the flood
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<br />insurance study for the City of Greeley. This study utilized the methodology
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<br />currently required by the Federal Emergency Management Agency. Topographic
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<br />mapping and river cross-section information from the previous flood study were
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<br />obtained from the Colorado Water Conservation Board and the City. The results
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<br />of the hydraulic analyses indicate that the previous study is reasonable. The
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<br />bridges at 8th Street, 5th Street and 6th Avenue are undersized and cause
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<br />backwater behind the bridges. The floodplain is very wide and generally
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<br />shallow. The floodway is wide in many locations preventing the development of
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<br />property adjacent to the river.
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<br />Erosion and sedimentation analyses were also performed. The Greeley
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<br />reach of the Cache la Poudre River is subject to excessive sedimentation
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<br />requiring dredging to clean out the channel. The river is subject to erosion
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<br />at bridge piers and at bends in the channel.
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<br />The following members of Simons, Li & Associates, ~nc. staff contributed
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<br />Project Manager
<br />Project Engineer
<br />Technician/Drafter
<br />Technical Typist
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<br />Wen-Sheng Liang, Ph.D., P.E.
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<br />Thomas C. Fairley, P.E.
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<br />Michelle K. Beckfeld
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<br />Rebecca S. Chappelle
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