|
<br /> "
<br /> 0
<br /> >
<br /> ~
<br /> 0
<br /> >
<br /> "
<br /> ,
<br /> ,
<br />H
<br />H "
<br />H "
<br /> "
<br />, ,
<br />H "
<br />"
<br />" U
<br />" "
<br /> H
<br /> 0
<br /> >
<br /> U
<br /> Z
<br /> "
<br /> 0
<br /> 0
<br /> ~
<br /> "
<br />
<br /> " H 0 0 0 0
<br /> , 0 , ^ ^ ^
<br /> , > H . . .
<br /> > , , H H
<br /> , 0 0 0 0
<br /> 0
<br /> 0 0 0 0 0 0
<br /> ^ . 0 0 0
<br /> ^ . . .
<br /> H 0 0 0 0
<br /> " 0 H > > .
<br /> , > H 0 0 .
<br /> , H
<br /> >
<br /> , 0 0 0 0
<br /> 0 0 0 0 0 0
<br /> 0 H . > .
<br /> H N N N N
<br />0 H 0 0 0 0
<br />. " 0 . , N N
<br />" , > H H H H
<br />, ,
<br />" >
<br />0 , 0 0 0 0
<br />~ 0 0 0 0 0 0
<br />" ^ . > . >
<br />0 H H H H
<br />> H 0 0 0 0
<br />0 " 0 ^ H H H
<br />, , > N , N N
<br />0 0
<br />0 >
<br />" , 0 0 0 0
<br />, 0 0 0 N N N
<br />" H 0 N H H
<br />"
<br /> H 0 0 0 0
<br /> " 0 " 0 0
<br /> , > H H
<br /> ,
<br /> >
<br /> , 0 0 0 0
<br /> ^ 0 . 0 0
<br /> . H N
<br /> H 0 0 ^ ^
<br /> " 0 ^ N N
<br /> " >
<br /> 0 -
<br /> "
<br /> , 0 0 0 ^
<br /> N 0 H ^ ^
<br /> N
<br />, 0 0 0 0
<br />< , . . ,
<br /> ^ 0 0 0
<br />0 . 0 . 0
<br /> ,
<br /> "
<br /> '0
<br />, 0
<br />0 0 " "
<br />, , 0 0 H
<br />" " " 0
<br />, " " " N
<br />0 " 0 0
<br />3 ., >
<br /> , , , ,
<br /> 0 0 ,
<br /> 0 " " "
<br /> 0 , , 0
<br /> 0 u " "
<br /> 0 .
<br /> 0 " "
<br /> H 0 0 .
<br /> H "
<br /> 0 " "
<br /> 0 , ,
<br /> u 0 0 0
<br />
<br />The frequency discharges at these sane loc~tions for the IOO-year
<br />event without Douglas Reservoir are shown in Table IV. The
<br />percentage increase in flow for this basin c~ndition is also shown,
<br />indicating a 15%-20% increase in the nagnitude of the flood peak if
<br />a bypass channel were constructed to direct all drainage flows around
<br />Douglas Reservoir. This impact in Fort Collins is significant, not
<br />only from increased flood peaks but also that larger magnitude drainage
<br />flows would be mo=e f~cquer.t and flood volumes could be considerably
<br />greater.
<br />
<br />'I'able IV
<br />
<br />Effect of Dougl~s Reservoir
<br />on IOO-Year Peak Discharge
<br />
<br /> With Dougl~s WithO\;.t Douglas Percent of
<br />Location Reservoir (ch) Reservoir (cfs) Increase
<br />Confluence with 27011 J~OO "
<br />"Paudre
<br />Dls of Caton Ditch 2900 3400 "
<br />t:/S of Eaton Ditcll 2')()0 3400 15
<br />C, S. Highway 2S7 2900 3400 15
<br />
<br /> ~
<br /> "
<br /> "
<br /> 0
<br /> "
<br /> "
<br /> 0
<br /> 0
<br /> , "
<br /> " ,
<br /> H
<br /> " ,
<br /> , S
<br /> "
<br /> ,
<br /> " ,
<br /> , ,
<br /> , 0
<br /> "" "
<br /> , ,
<br /> o ,
<br /> " ,
<br /> " , ,
<br /> "
<br /> '" ,
<br /> ,0 ,
<br /> ,,' ,
<br /> ,
<br /> ,0
<br /> " 0
<br /> " ~
<br /> 00 ,
<br /> ii! ,
<br /> ,
<br /> ,ri "
<br /> .-<0'-'
<br /> DO 0
<br />" , " ,
<br />0
<br />"
<br />0 ri<
<br />, 0 ,
<br />" 000
<br />
<br />The hydrograph in Figure J shows an early, secondary flood peak that
<br />is generated from runoff on im?erviolis areas in the lower Dry Creek
<br />basin, ,"lood plain improvement alterniltives such as channel Jiversiolls
<br />or flood detention up"tr",am of t.he T,,3rimer-~:eld C,lnal would not elininatc
<br />the need to provide facilities to convey this localized drainage.
<br />
<br />-15 -
<br />
|