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<br />FLJTUREFLOOD5
<br />
<br />This section of the ropo.t disc~esos the Standard
<br />Projsct flood and the Intermediate Regionel Flood on_"IoJlu"'ont
<br />Creek in the vi~inity of Colorsdo Springs, and some of the hazards
<br />of gre-at floods. Thll5tandarctProject Flood represents the reason_
<br />"bhuppllr limits of expected flooding. Floods of Intermediate
<br />Regio~sl Flood size ~~y be exp8cted to occur ~ore often, but they
<br />will ~ot be as severe as the infrequent Standard Proje~t Flood.
<br />L~rge floods havo o~c~rrod in the psst on Monu~ent
<br />Creek and cthar tributsries of Fount~in Creek in the general geo-
<br />graphical and physiographical region of Colorado Springs. SBv~re
<br />stO~5, similer to those causing past floods, undoubtedly will
<br />r~CUr in t~e M~nument Creek watershed to ~~use future flQods of
<br />ecual or gruater aiLe. In ~ny dotarmination of futuro floodc
<br />,"ht~~ m~y n~",," nn ~ given stre"m, it is de~iretlle to ccnsider
<br />811 ~to~mo Dnd flood~ thct h"vo OC~LJr~ed in the region 0<' "..tar-
<br />~hed~ ~ith similar topography, wat~r~ha~ ~aver, ~nd pnyslc~l
<br />cnari;cteristics.
<br />
<br />Intermediate Regional flood magnitude, ~nd its peak discharge
<br />approached that of the Standard Projeot Flood._50,OOO versus 63,400
<br />cubi~ feet per s~cond.
<br />The maxi~um known floods that ~~ve occurred ~ithin th~
<br />geographical region ~re lIsted in Table 4. flood characteriatics
<br />of the Intermediah Regional flood for avaragetJ '''a~i",um C{Jndition~
<br />within the study raacheg are gho~~ in Teble 5.
<br />
<br />Inta~ro~i3tG R~4ional flood
<br />
<br />Stanaard Proiect flood
<br />Only in rare inotances han a ~pc~ific otre~rn experienced
<br />tne largB9t flOOd that is potonti"lly possible. Severu ~6 th~ '''a~l-
<br />~urn known flood may havB been on any given 8tream, it i~ g~ner~lly
<br />~~cepted thet ~ l~rger flood ~ill sooner or later occur. The Stan_
<br />dard Project flood is defined a8 the flood that CaJl be expacted
<br />from the most severe co~binetioJl of meteorological and hydrologi~~l
<br />~onditlons that is consider~d reasonatlly characteristic of the
<br />geographical llrea in which the drainage basin is loc~ted, excluding
<br />extremely rare combinations. The Corps of Engin~ers, in cooper~tion
<br />with the NOAA Wellther Servic", I,.", made cornpr"hensiv" ~tudies lInd
<br />investigations bes~d on tho vest records of expe~i~nc8d storm~ ~nd
<br />
<br />The Intermediate R8gion~1 Flood is defined ae having
<br />'HI "v~L'a\is fr(l'lUBncy of OCGurr~nc~ cf once in 100 years, ~t "
<br />deeignet~ location, although it may occ~r in any ye~r and po,-
<br />sibly even in ~ucC8ssive yoars. Th~ Intermediate Regional Flood
<br />rep.sssnta 8 major flood, ~lthough it io 1~88 sever~ th~n the
<br />St3n~ard Project flood.
<br />Tho m~Qnitude of this flood on th~ fllonulOsnt Creek
<br />study reachwes deterrnined frOOlstatistical analysis of rngicn"l
<br />~nn".,l re~~ fln" rAr.ords. Also, the vari"bl" rainfall and runorf
<br />char"cteristics of she","s in tlw '.lunar"l ragion were compared,
<br />adjo~ted ~hen nGceeoary, and u3ed for the ~naiysi5. The M~y 193~
<br />f!Dod on Monument Crpek at Colorado Springs ~~s larger then
<br />
<br />flouJ~ ",,,J 1,,,~ "v"lv;-,d 9~r>~~"1l",,,,d p1;ucedur.." for cct1",,,t1~,.. t~~
<br />
<br />flood potential of waterwayu. flood ch~racteri$tics of the St~ndard
<br />Project Flood fo~ aver~ged maximum conditions within th~ study rea~he3
<br />"re shown in Table 5.
<br />
<br />Freouuncy
<br />
<br />By definition, the IJlter~ediat" RGgion~l flood has ~n
<br />~v~rage oc~urrence freque~cy of onc~ in 100 years. It is imprac-
<br />ticel, however, to aS$ign ~ frequen~y to the greeter Standard
<br />Proje~t floOd. For purposes of hazard ovaluation, it is impcrtant
<br />to recognize that eithor of the3e ~ejor floods c~n oc~ur ~n sny
<br />year. floods larger than the Standsrd I!roj~d Flood ere pogeible,
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