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<br />e <br /> <br />tit <br /> <br />e <br /> <br />Table 3 (continued) <br />Definitions for regulating approximate Zone A floodplains <br /> <br />Limited Development: Development involving parks, open space, golf courses, agriculture, bridges and <br />culverts that serve a single farm/home/cabin, pole barns, and individual single family structures_ <br />Significant Development: All development that does not fall under one of the categories listed under <br />the Limited Development definition. A special case of significant development is a development that <br />involves more than 5 acres or more than 50 units (whichever is more restrictive), This special case is' <br />important because federal regulations require that a detailed study be submitted to the community by the <br />developer. Failure of the community to require a deUliled study will result in a violation of the National <br />Flood Insurance Program, which can have negative impacts on floodplain property owners within the <br />community, <br />Approximate hydrology: ] OO-year peak flow values estimated for the hydrologic points of interest <br />using CWCB "Guidelines" regression equations or other accepUlble approximate hydrologic method <br />approved by the CWCB. <br />Detailed hydrology: lOa-year (and ]0-,50-, and 500-year when applicable) peak flow values computed <br />for the hydrologic point of interest using an acceptable detailed methodology, other than the <br />"Guidelines", such as an at-site stream gage analysis, a regional stream gage analysis, or a rainfall- <br />runoff model. <br />Approximate hydranlics: Water surface elevations or flow depths computed for the location or reach of <br />interest using normal depth flow calculations (i,e, Manning's equation/slope-area method). Computer <br />programs such as QU]CK-2 and F10wMaster are excellent tools for this purpose. <br />Detailed hydraulics: Water surface elevations (base flood etevations) computed for the stream reach of <br />interest using a step-backwater computer model, or other acceptable one-dimensional or two dimensional <br />computer model, such as HEC-2 or HEC-RAS. <br /> <br />;and <br /> <br />WHEREAS, the approximate floodplain information in said report with included maps fOT <br />stream reaches in Jefferson County as listed in Table I meet the requirements for approximate <br />floodplain information as listed in the Board's "Rules and Regulations for the Designation and <br />Approval of Floodplains and of Storm or Floodwater Runoff Channels in Colorado" (2 CCR 408- <br />I), contingent upon the understanding by Jefferson County of the need for a case-by-case review of <br />all development proposals within the corporate limits; and <br /> <br />DESIGNATION AND APPROVAL ACTION <br />NOW, THEREFORE, BE IT RESOLVED by the Colorado Water Conservation Board in <br />regular meeting assembled in Salicla, Colorado, this 27th day of September 1999, that it does <br />hereby designate and approve as approximate floodplain information the storm or floodwater runoff <br />channels and basins, as listed in Table I and as described by approximate floodplain information in <br />said Jefferson County Flood Insurance Study dated July 4, 1989, with included maps that meet the <br />criteria for the "Board's Rules and Regulations for the Designation and Approval of Floodplains <br />and of Storm or Floodwater Runoff Channels in Colorado" (2 CCR 408-1); and <br /> <br />5 <br />