|
<br />",,0 '
<br />against the southern and eastern basin boundaries on the Con-' ,.
<br />0,12
<br />tinental Divide. Each flood event assumes that the snowpack ;~~
<br />, .,
<br />II . ,_ ~__ .. ~\.<t",
<br />i/\,: ~s of~v=rage th~ckness, creat~ng a~e fnowmelt runoff, ":'''_' r
<br />.tr\.! fThe areal distribu.!l2.E for each ~f the s~rms was a function of \'
<br />I ',:-t / ~, the region's average ~onthly temper.2~ and the volume. of j
<br />'\ ~ l rainfall. The dimensions of the storm and its location within _
<br /><,~ -the basin were calculated. by meteorological consultants, \'v,I,~ N '<':""',
<br />I I;t ( \';.ov r< ~J -t\tl.Vt (I. ~().v( {.L,~,- i..l...-'2- ,( vv,} &"~ \.a.SI"
<br />. ".. ,...,.,.~~
<br />(' The Intermediate Regional Flood is one that could occur on
<br />the average of once every 100 years, although it has a 1% chance
<br />I of occurring in any given year. The Standard Project Flood is
<br />one that is generated by the most severe combination of
<br />meteorological conditions reasonably characteristic of the hydro-
<br />( logic region excluding extremely r,are combinations. ~ipit:ation
<br />. for the 10 and 25-year, and the Int~rmediate Regional and I
<br />r4J S~andard pr?ject,Fl-o~~ere derived from_statistical analysis j vJ~iJ";.
<br />of rainfall data by the U.S. Weather Bureau and presented in ~/
<br />. ~ tlL\
<br />~ Technical Paper 40.,[ Peak flows for the four flood events are 12
<br />--- -- ~ ,- ,- ,'- . 1 _
<br />shown in Table for selected locations on the streams. > '~
<br />,
<br />'ii!
<br />
<br />
<br />I
<br />I
<br />I
<br />I
<br />
<br />I
<br />I
<br />I
<br />I
<br />
<br />I
<br />
<br />I
<br />I
<br />I
<br />I
<br />I
<br />I
<br />I
<br />
<br />,.CI,
<br />0,)
<br />I
<br />
<br />18
<br />- ). -
<br />
<br />'<--r-
<br />
<br />TABLE 2
<br />
<br />li ,f (,')
<br />
<br />'5 t"
<br />
<br />,';:",-, .
<br />
<br />.~ ) ~ c
<br />,,~
<br />
<br />(,l
<br />'1 \
<br />I, ()
<br />'''1-)'\
<br />
<br /><i.' ....
<br />.,".\ t
<br />./ I'll
<br />
<br />PEAK DISCHARGES, CFS
<br />
<br />Location
<br />
<br />10-yr.
<br />1436
<br />
<br />Into Tarn Reservoir
<br />
<br />Out of Tarn Reser~if ')
<br />
<br />Above French Gulch~/(~~~
<br />-- , . "1
<br />Below French Gulch ~,'i""
<br />
<br />Below North Barton ~4'
<br />Gulch
<br />
<br />Upstream Dillon Res-
<br />ervoir (below Swan
<br />River)
<br />
<br />558 u
<br />7981,~
<br />"14
<br />875
<br />
<br />925
<br />
<br />1122
<br />$'p\
<br />
<br /><--
<br />I ~, Ill" t-.J
<br />
<br />25-yr.
<br />
<br />Intermediate
<br />Project
<br />Flood
<br />
<br />2087
<br />720
<br />8652
<br />
<br />9422
<br />9922
<br />
<br />Standard
<br />Project
<br />Flood
<br />" (.;
<br />2900 ~3"~ 21,~~dt~'
<br />1880~. U,2~"/.'-'j
<br />
<br />943 ".M"," 8,717
<br />1411 ; ','> 14,044
<br />1461 ,;"'/",,,, 14,094
<br />
<br />11892
<br />1(2(1'2.
<br />
<br />_Il-l_,-,
<br />fdoj.~
<br />1ti,{'
<br />
<br />14,291
<br />"2,100
<br />
<br />1658
<br />T>-\ (1'7
<br />
<br />11")
<br />
<br />Ipeak flows that affect the town of Breckenridge; because of
<br />the type of storm, the peak flo.ws include the contribution~-r
<br />of ,Illinois, Lehman, and Sawmill Gulche? -l
<br />- --.::- ~-c^ ___''_ _. _'
<br />2 ' ,
<br />Storm,c~tered over Lehm~n Gulch, no contribution from Tarn
<br />
<br />Reservoir except'for snowmelt.
<br />
<br />II I"
<br />........::." t I,.).A~'('''' .
<br />
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