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<br />The minimum flow,recommendation for all life stages of rainbow anQ brown
<br />
<br />'i;~~~!;~tf~"'2;=;Y4m~fifi~~ii~~~~~~~er~~~~~~~:n~i:~;~::c~'~~:i:~:'~s
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<br />'below' 300 'cfs begin'tci"cause dramatic reductions in spawning habitat for
<br />both rainbow and brown trout as well as significant decreases in total
<br />wetted surface area.
<br />
<br />Optimum flows for brown and rainbow trout spawning, incubation, and
<br />hatching are l,200 and,l,OOO cfs, respectively. These flows provide access
<br />to extensive higher elevation spawning beds composed of optimum-sized
<br />gravels that are not, available at lower flows. The 300 cfs minimum and
<br />optimum flow is also recommended for rainbow and brown trout fry and
<br />juvenile life stages.
<br />
<br />The optimum flow recommendation for adult rainbow and brown trout is 500 cfs.
<br />
<br />Water and power management agencies (U.S. Bureau of Reclamation [USBR]
<br />Uncompahgreo.Valley Water User's Association [UVWUA] Western'AreaPower
<br />Administration [WAPA]) have become acutely aware of the public interest that
<br />has developed concerning the world-class trout fishery in the B!a<;,1<;-.CaIlYo~
<br />,of the 'Gunnison in the 1980's. This awareness hasre'sulted int'much::'inore:,-j
<br />1""'...-'"<;_'1-i--_........,.,....-.... ,'--- ^"---.~:l?{.:r:--...\.,.'"""-~....o._.,~"-:.,....,;.,...,>- -- __- .'-~""" '. _ ,__,___ '-......._0_< 'r""-'Y:_-'''':-'''_.'- _ ._ __..~____ _ _~"'"' ~
<br />"a~,~~,~1q~f!~".~,be~~:.stiJc~:n';lly,.t/)~SJ~:<'III<1~~e~~1I,!;.,agencies 'to D1inimize..:tl1e ,."
<br />.t!l!IlJlg,j;.clur~ticin.,;-,an4{!JU'lgnitu4ef,Df: flow: ~W$rl!l!1i'!.Rns.;'Q~,th7,~R',!l1n1S~~1!8r. .
<br />,As./i ;-~s1hl!;,~.ot..tW!l_AAt.entioq."t9" deEag ,!~1J..:.,]!,~,~~~~!;9IlS.}~J;.!!!;~_!~':very i
<br />.s~r!2pg;yeas:c1.:!lsses !1986;-:-1988)',of,:both: rainbow':and?brown trout'itf>theT
<br />Gunnison' Gorge. ' "",:,."",,.,, ."
<br />.-.-'--.. " -'
<br />
<br />Middle Fork of the South Platte River
<br />
<br />Brown trout are the only viable resident wild trout species in this
<br />river above Spinney Mountain Reservoir at the present time. Minimum flow
<br />recommendations for all life stages of brown trout are 20 cfs,whlle optimum
<br />flowrecommeildations vary from 20 to 60 cfs, depending upon the life stage
<br />(Table 3). The lack of a USGS gage and discharge records for this section
<br />of river precludes any evaluation of how often the minimum and 'optimum flow
<br />recommendations can realistically be met.
<br />
<br />Rio Grande River
<br />
<br />Minimum flow recommendations for all life stages of brown trout are lOO
<br />cfs, while optimum flow recommendations range from 150-200 cfs, 'depending
<br />upon life stage (Table 3). Minimum flow recommendations for rainbow
<br />spawning, incubation, hatching, and adult life stages are 200 cfs versus 100
<br />cfs for rainbow fry and juvenile life stages.
<br />
<br />Optimum flow recommendations for brown trout range from 150-200 cfs,
<br />compared to 300-500 cfs for rainbow trout, depending upon the life stage.
<br />Examination of the flow records for the Wagon Wheel Gap USGS gage indicate
<br />that the minimum flow recommendations can be met in most months of most
<br />years. The minimum flow of lOO cfs ,has been met or exceeded in every month
<br />since October 1979. Thus, water management agencies should have little
<br />problem in maintaining this minimum flow most of the time under present
<br />operational patterns.
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<br />I) tJ0002392
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