|
<br />,
<br />
<br />100000
<br />
<br /> 10000
<br />0
<br />...
<br />C'l
<br />E
<br />.
<br />III
<br />~
<br />. 1000
<br />.c
<br />u
<br />.
<br />'0
<br />,.
<br />.
<br />.
<br />Q.
<br /> 100
<br />
<br />PMF range
<br />
<br />..,.,.,.~-,.,.,.._....,.,...,.....,.,...,.,.,.......,.'.'.'.'.'.'.'.'-'.'.'.'.'.'.'.'.'.'.'.,.,
<br />,.,.,...'t.'.''''.'.'.'.'.'.'.'.'.'''.'-'.'.'.'.'.'.'.'."'-'."'."'.'."'.'.'-'.'.'.'.'.''''.'-',
<br />
<br />Design flood
<br />
<br />-.'.'.'.-.'.'-'.'.'.'.'.'.'.'.'.'.'.'-'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'......-.....-.-...
<br />
<br />.............................................. ,..
<br />
<br />.................
<br />Gage (30 years) ........"...,.., 1..'-'....,..,-,.., ..
<br />\ ,'''" ..............
<br />"',x..;;:' ;..' ~_,....,....."...// ,...,... 95'10 confidence
<br />
<br />........., ,.......
<br />/ / ../.. Max paleoflood
<br />.../t~. .,.;..............
<br />/ / Gage wI P=2,500 years
<br />
<br />/,}':::::....',:,.../
<br />
<br />./.....
<br />.,..
<br />...
<br />
<br />intervals
<br />
<br />10
<br />1
<br />
<br />10
<br />
<br />100
<br />
<br />1000
<br />
<br />10000
<br />
<br />100000
<br />
<br />Recurrence interval, years
<br />
<br />Figure 6, FIood.frequency relations for Cherry Creek near Melvin (06712500) with paleoflood data
<br />(shown as a rectangle, which reflect ranges of the magnitude and age for each paleoflood) with 95-
<br />percent confidence limits, The original design flood and probable maximum flood estimates for
<br />Cherry Creek Reservoir are shown for comparison,
<br />
<br />There are over 10,000 dams in the Rocky Mountain region that may need to be modified for
<br />current PMP criteria during dam safety recertification. Large differences in maximum paleoflood
<br />and PMF values in eastern Colorado, elsewhere in the Rocky Mountains (Jarrett and Costa, 1988;
<br />Ostenaa and Levish, 1995; Jarrett and Tomlinson, in press). and the trend to use risk assessment
<br />studies for dam safety suggest additional hydrometeorologic research is needed to reduce
<br />uncertainties, Thus, it is important to develop methodologies that can be used by dam-safety
<br />officials,
<br />
<br />9
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