Laserfiche WebLink
<br />5. Perform detailed hydra~li~ analysis of the existing hydraulic <br />structures and determine the flow patterns along the study reach. <br /> <br />between the 4 feet original contours were provided for the final mapping <br />used in this study. <br /> <br />areas. <br /> <br />The Colorado ~ater Conservation Board performed field surveys <n february, <br />1979 to verify the accuracy of the mapping. Twenty cross sections along the <br />Coal Creek study reach were field .urveyed and the base maps were found to <br />meet the required National map standards for accuracy. These surveyed <br />crOsS seer ions vere used in the computation of the water surface profiles. <br /> <br />6. Conduct hydraul~e routings to determine flood profiles and flooded <br /> <br />7. Delineate the lOa-year floodplain and define floodway limits. <br /> <br />R. Formulate a flood control and floodplain management plan for both <br />the urban and rural segments of the study reach. <br /> <br />These maps were scribed and used as base maps for the floodpla~n de- <br />lineation. Land use information vas updated to 1979 conditions using field <br />surveys and recent contour mapping of the Boulder Creek confluence area <br />provided hy the Urhan Drainage and Flood Control District. <br /> <br />9. Prepare a final report documenting the results of the study. <br /> <br />Prior to the publication of the final report, the sponsoring agencies <br />dC'lTerl the inclusion in the report of information related to the flood <br />history, flood damage assessment, and economic analysis of the recommended <br />plan. This information waS prepared jointly by the sponsoring agencies and is <br />presented in Chapters IV, VII, and XI, respectively. <br /> <br />E. Related Flood Studies <br /> <br />C. Organization of Report <br /> <br />The flood ha~ard analyses report (reference 1) prepared by the U.S. Soil <br />Conservation Service (scs) included the subject study reach. The 100- and <br />SOO-year floodplains were delineated in that report. In 1978 the Federal <br />Insurance Administration, whicb was recently renamed as the Federal E~ergeney <br />Management Agency (FEMAl, used the SCS report results to publish a flood <br />insurance study for Boulder County (reference 2). <br /> <br />This report is divided into two main parts. The first part provides in- <br />fnrrn~tion rnnceTn;n~ floorl h~~~Trl ~Tea' h~serl nn exi~ting devel~p~ent ~on~ <br /> <br />ditions. The second part discusses the recommcnd~~ flood control and flood- <br />pl..in man..gement plan whiCh could be i"'plcrnent~d alon~ tile Sludy reach to <br />reduce potential flood dam..ges. <br /> <br />After the above studies were publi.hed, the accuracy of the study results <br />in the vicinity of Erie was challenged by a n~",het of concerned individuals. <br />Subsequently, these questions were reviewed by the Colorado Water Conservation <br />Board ~taff. It was concluded that the hydraulic analysis portion of the <br />study needed additional refinement and further detailed analysis. <br /> <br />D. MaPPinK and Surveying <br /> <br />These conclusions eventually led to a decision to initiate a new study <br />wbich entailed the tasks listed in the Scope of Services of this report. In <br />add~tion to the floodplain delineation, this study includes a significant <br />'''"Dunt of effort aimed at pr"viding a flood contrel ..nd flOOdplain management <br />plan for th~ study ar~a. <br /> <br />Contour mapping for the study "as ptovided by the Color"do "'.lter r.{)ns~r- <br />vation !>oard. This mapping, dated July 1974, has a scale of 1 inch ,,~ual to <br />200 feet and a contour interval of 4 feet. Additi(mal contours interpolated <br /> <br />-4- <br /> <br />- 5 - <br />