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SUMMARY OF FLOOD SITUATION area, large floods ther", last about 2 hours ..hlle t~seon Bear Creek would lastuptollboutl2llours. 8earCreekorl<llnateslnthohigh..ountalns8mlleseast of the continental dlvid... Th" strea.", Ilows eastward across the front range IInd out onto the high plains to Join the South Platte River in the southern Denver rnatropolltan <lrea, Morrio.onlies 10 miles upstrei'Jm Irom tho mouth of Boar Creek and occupies a I mi Ie lenqth of the flood plain lying In the depression between the hogback and the mountains. The flood plalnaverllges 500 feet In width and Ispartlallyurbani2ed. Mount Vernon Creek drains a sm1ltl area of the front range northwest of Morrison. The creek tlows eastward to the hoqback and than south..esterly to Join Bear Creek in Morrison. The flood plain averllges 100 feet In width except whero it wldons nlldr the mouth to join tha Bo"rCrellk flood plaIn. . . . I , , I HAZARDOUS CONOITION$ would occur during I"rqo tloods as a result of rapidly rIsing water levels, high velocities, and deep overbank flows. Velocities greater than 3 feet per second c~blned with depths ot 2teetormorearegenerallyconslderedhalardous. Thesecondltlons should be expected on the Boar Creek and Mount Vernon Creek flood plains. . . . . . . fLOOD CONTROL AND DEFENSE is limited to some masonry channel wall constructlonneartheupstreamendofthe.BearCreeks+udyraachand on Mount Vernon Creek near the mouth. The rapid rise of the streams limits the warning time 50 that I ittle more than personal evacuation can be accomplished. A fload control project consIsting ot channel ImprovementsonBoarandMountVernonCreeksln"1orrlsonw/lsautho_ rlzed by the F load Control Act ot 1944, The ~roJect was <:::las5lt led "lnactlve"on.23March 1961 and has not been built. . , . THE CAUSE OF FLOODS On Sear Creek and Mount Vernon Creek has bean from Intense su"""er rainstorms, sometimes with h6llvy snowmelt rurw:>tf added. GREAT FLOODS have occurr!td at Morrison, notablv In 1896 and 1938. The largost flood on Boar Creek occurred inl896andhlldanestlmated peak dlsch/lrge of 8.600 cubic feet per second (c./.s.l. A flood of this Sile or Iilr"...r hilS aoout " I In 40 chllncc of recurring In ".['y The largest known flood on l.1ountVeroonCreekoccurrad iol938 year. with II peil~ discharge of 6,200 c.f.s. . . . FLOOODAMAGES,In<:ludlng 1055 of human Ilfe,havcbeengreiltdurlnq past floods at Morrison. The potential floods studied in tills report would produce damages which are more severo than tho d/l"agas exoeri- enced by the Ollst floods. . . . DURATION Of FLOODiNG at Morrison ;5 short due to the steep channel slcpos. Because ~unt Ve~~~ Cree_ hll~ con~ld~r"hlv smaller dralnaQo ,