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-2- For those subbasins mated based on the basins E and I. The HEC-I model schematics for basins E and I are illustrated on Figures 4 and 5, respectively. The runoff rates for the subbasins are summarized in Table I \ ' '.~~ , " J \ . \ .., . - , ~:d" \ v." runoff rate runoff rate not specifically modeled, a -----'"~- .'.,....,<,~._"".~ ...~...". proposed land Illse and the was approxi- computed for Table 3 also presents the cumulative lOa-year peak flow rates at pertinent design points. Once again, if the basin was not modeled specifically, the flow rates wereap~,~~_.!?:~U~!L,the proposed land use in the basin and the results of the basins I and E HEC-I computer models. .' , The supporting hydrologic documentation and computer output is given in Appendix A. LOMR Elimination of Delineated Drainageways First, BMP is requesting that the drainageways with 250 acres or less of ----. drainage area be eliminated from the FIRMs. These drainageways are marked on Table 3. The basis for this is given below. A.I' ..- __,1- ~."_/' I J. Table 3 presents the maximum tributary area for each drainageway and the approximate 100-year peak runoff. As seen, the majority ,I of drainageways and ti"\< '. ~ '+, ~ the have ttibutary areas less the 250 acres 1\ thus, peak fl ows less than 500 cfs. With channel slopes between 5 b:~ and 10 percent and the existing channel configuration, the 100- SCCt-' p'd'. i. year depth of flow would be between 0_5 and 2 feet. 2. In the Denver area, a drainageway is not considered a "major" _/-- drainageway until the tributary area exceed 130 acres, ____-f'ht;" "major" drainageways are mapped on FEMA's FIRMs and FHADs by the (') _I /f'(: ,,' ...'<-- 'v!; '\'." \., J IA' 'I VI" \/ "1 :,." \ J." , ,. \ .-. \ ~,+)c>v Jj2":I\ 'j ,,\ o,,L{ ~) ,VII v\ r-;, \~~jvVC \,).' -} ( "V I ( I, cll\') 1'1 1/11. ) /\ 1/\" 'f\^ "/ '.J ' '/'- \ ,I 5 ~ I () "1 -C"'VV-