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<br /> Table 6 Regionlll Basin Designations <br />coo< DciiCription C,Kle De,.;rip!ion 0"'" Descripll(ln <br />,CC k~ Ca'~ Creel NMC Nonh Mooumenl Crccl MC MooumcnlCrcel <br />R.\~ J{;].,p:x:rryMc::.~:".m I'L !":.:J=rbk. OWC DL'ty w"m"~ C....,k <br />TC TeaehourOeek EG En,ignGu1ch ,,'C SourhBeawrCreel <br />ULC Hel1Cr~eI< NBC North BcaverCreel BC Bc.werCreek <br />"YC HayCr~<;k 'C J""..(~, C'eek " B\aI;kForcst <br />'C SmilhCreek MB MonumcolBmnch MT Mi<ld1eTrillutary <br />N Jack',Valley DMC De<ldmao'sCn:e. " lch"Ja/lRun <br />D' D()u~l:1s Valley WMC We<tMOllumenlCrool "'C Black Squirrel Creek <br />'L" Elktwm KC K~IUeCrecl. DOY Dry Creek <br />S'" South Pi"e Creek CC C<JIlon"'""dCn:d '" PineC"",. <br />" :-:onhRcckrimmon " S"uthRockrimm"n " P"pesBluff <br />DOC D"u~l,,_'C"'ck TG T~"'p1ctonGap 'OS Ro,,,clt <br />eM Pap<-~(~l MES M<.\<a MVP MunumcmValky <br /> <br />Hydrologic data for each sub-basin was developed using the Soil Conversation Service <br />($C5) Dimeosionless Hydrograph Model within HEC.l. Basin characteristics required for the <br />SCS Dimensionless Hydrograph Metltod using HEC-I are area, curve number, and SCS lag time <br />(flag)' Basio areas were planimetered to determine their area io square miles. Curve oumbers <br />were determined for each sub-basio utilizing the hydrologic soil type. ground cover (both <br />existing and proposed), and Tables 5-4 and 5-5 of the City/County Criteria ManuaL The <br />calculation of the SCS lag time ",'as based upon its relationship to timcofconcenrration (tc;l, <br />The time of concentration for each sub-basin was delermined by adding travel times for overland <br />flow, channel flow, and pipe flow from the hydrologically most distant point in the basin to the <br />outfall poiol. The parameters used in these calculations were determined from available <br />topographic maps, soils maps, aerial pholOgrdphy, land use maps, and field investigation. Figure <br />3 shows the hydrologic soil types within the Monument Creek basin. For areas which are <br />currently undeveloped and underlain with "Type A" soils, it was assumed that "Type S" soils <br />would exist in the developed condition and the curve numbers were modified accordingly. <br />Five existing major flood cootrol structures have been included in the hydrologic model. <br />These structures are Rampart Reservoir, the Kettle Creek Detention Pond also known as the Air <br />Force Academy Detention Pond, Briargate Detention Pond II, lUld the Chapel Hills Detention <br />Ponds Numbers I and 2. The detention ponds were included in the hydrologic model because <br />they are considered flood control structures by the State of Colorado. Rampart Rcservoir was <br />included based on discussions with the City of Colorado Springs Water Department regarding <br />the operation of the Reservoir, Rampart Reservoir is not considered a flood control structure; <br />~c'.;'ever, c::e to L~e war the reservoir is Cpe!"ated it acts:1S a floud nmtm! stfllclure. <br />The impact of proposed drainageway improvemeots have not been considered in the <br />hydrologic model. Proposed improvemenl~ such as detention/retention basins and their effect <br />upon peak discharges will be evaluatt:d in the alternative planning phase. Future Channel <br />.""Clions which may slow or speed up the tr.\Vel time of peak flows will also be modelled in the <br />ahernative planning hydrology. <br />Sub-basin flows were routed and/or combined with other sub-basin flows to establiSh <br />discharges at ,arious points throughout the Monument Creek basin. Routing of Hows was <br />aaomplished using the kinematic wave methud, The kinematic wave method is ba.>ed upon <br />characteristics of each reach including length, slope, Manning's roughness, type of channel, <br />bottom width of cltannel, and channel side slope. Flows from up:<tream suh.basios Ot design <br />puinl'(puinL'ofeornbint:d flow) wererouteJ through the channel reach detcrmining the chanoel <br />storage and lag time for the routing. At design poims, two or more hydrographs Wert: comhined <br />to detennine thc outflow hydrograph at that particular point (in the illpUlto thl;: HEC.l compuler <br /> <br />already been recognized as drainage basins by eithcrthe City of Colorado Springs or EI Paso <br />County. Some ha.,ins such a., Monum~nt Valley and Papeton have replaced basins previously <br />recogoized as "miscellaneous" basins. This was done in order to distinguish between the so- <br />called "miscellaneous" basins within the sludy area. <br />The regional basins have been further sulxlivided into sub.basins. These sub-basins are <br />rougltlyone square mile in area. Some basins may be slightly smaller or larger than one square <br />mile depending upon the location of the most logical sub.ba,in divide(s). Each sub. basin has <br />ocen assigned an alphanumeric designation, This designation is betwecn four and six cltaracters <br />in length. The alphabetical chatacters in the designation represent the stream or the regional <br />basin in which the sub-basin is immediately tributary. Table 6 shows the meaning of the <br />alphabcticalcharacters in the sub-basin designations. The numbers in the sub-basin designation <br />are unique to each sub-basin. Each sub-basin has a unique number identifying it. However, Wilh <br />man)' different sub-basins the addition of the alphabetical characters allow for a quick <br />determination of where within the Monument Creek basin that particular sub-basin lies. <br /> <br />TV.' <br /> <br />TV.' <br />