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TABLE 6 Definitions for Rel!ulatinl! Approximate Zone A Floodplains e Term Definition Regional Any current published regional regression equations by the CWCB or Us. regression Geological Survey that estimatel OO-year peak flows for streams in the geographic equations area of interest - . Limited Development involving parks, open space, golf courses, agriculture, bridges development and culverts that serve a single farm/homelcabin, pole bams and individual single . familv structures Significant All development that does not fall under one of the categories listed under the development definition of "Limited development "; a special case of "Significant development" is a subdivision that involves more than 5 acres or more than 50 lots (whichever is more restrictive); this special case is important because regulatory criteria for communities participating in the NFIP require that the community receive a detailed floodplain study for any such subdivision within an approximate Zone A floodolain Approximate lOa-year peak flow values estimated for the hydrologic point of interest using hydrology CWCB regression equations or other acceptable approximate hydrologic method aDDroved bv the CWCB Detailed hydrology lOa-year (and lO-year, 50-year, and JOO-year when applicable) peak flow values computed for the hydrologic point of interest using an acceptable detailed methodology, other than approximate regression equations, such as an at,site stream gage analysis, a regional stream gage analysis, or a rainfall-runoff model Approximate Water surface elevations or fiow depths computed for the location or reach of hydraulics interest using nonnal depth flow calculations (i. e. Manning's equation or slope-area method) or using regional depth-offlow regressions approved by the CWCB; computer programs such as QUICK-2 and FlowMaster are excellent tools for nonnal depth flow calculations Detailed hydraulics Water surface elevations (base flood elevations) computed for the stream reach of interest using a step-backwater computer models, or other acceptable one-dimensional or two-dimensional comnuter model, such as HEC-2 or HEC,RAS e DESIGNATION. APPROVAL AND RESCISSION ACTION NOW, THEREFORE, BE IT RESOLVED by the Colorado Water Conservation Board in regular meeting assembled in Gwmison, Colorado, this 24th day of July, 2000, that it does hereby designate and approve as detailed floodplain information the 100-year floodplains as described by the floodwater surface elevations and profiles in said new report, dated July 24, 2000, for the study reach listed in Table 3 and that it does does hereby designate and approve as approximate floodplain information the 100-year floodplains as described by the approximate floodplain delineations in said new report, dated July 24, 2000, for the study reach listed in Table 4, contingent upon the understanding by the Town of Basalt, Eagle County and Pitkin County of the need for a: case-by-case review of all developments within the approximate floodplain, based on a detailed hydrologic and e 6