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<br />UJ2l78 <br /> <br />to 30 cfs immediately. SO cfs on June 20. and remained at 50 cfs for the retDllinder of the summer. Subsequent <br />sampling of tbe river in the fall of 1990 and twice in 1991 indicated that the low flows during 1990 caused II <br />significant loss to the trout fisbery. Estimates of trout biomass rtlIlde in the faU of 1991 were about 11 Ib/ac <br />throughout the quality trout section. The loss was attnbuted to a combination of elevated water temperatures in the <br />- lower portion of the quality trout section and a severe reduction in available physical habitat, <br /> <br />From November 1990 to the present. McPhee Reservoir has been operated under aD interim Qperating agreement as <br />described in the Background section of this document. The trout fishery had recovered significantly by the fali of <br />1992. Biomass estimates made in 1992 and in 1993 indicated the river contained 40 and 64 Ib/ac of trout, <br />respectively. However, the biomass estimate made in 1993 included fish that were lost from the reservoir the <br />previous spring during a spill rei~e. Agency biologists IIgreo:! that 64 lh/ac represents a much higher biomass of <br />trout than the long-term carrying capacity of the river under tho:! interim operations. <br /> <br />Dolores River Native Fishery - Since the closure of McPhee Dam, the most comprehensive study of the native <br />fishery was conducted in 1991 and 1992 by Bio/West inc. "During the c0urse of this study, six .native fish species <br />were collected from McPhee Dam downstream to the confluence with the Colorado River. The species were: <br /> <br />Colorado squawfisb t'Ptvchocheillle ~{fedeTRlly protected} <br />Roundtail chub (Qila mOlleta) <br />Speckled dace (~r-;n;-h'hv< o~::llhts) <br />Fianoelmouth sucker (Catastomus iatipinnis) <br />Biueoead sucker (Catostomus discoboius) <br />Mottled scuipin ~ hll.iI::di). <br /> <br />Colorado squB.v,fish. t.>te only enciangered speciecollecteG during this survey, were found within l.25 miles of the <br />conflueDce with the Coiorado Rive~. it v.."IlS presumed these fish were not year-long inhabitants of the Dolores Rive~, <br />but rather temporary migrantS from the Colorado River. However. thineen potentiai spav..ning sites for Colontcio <br />squawfish were identified and it was conciuded the Dolores River provided suitable habitat for the reintroductioD of <br />this species and the razorback sucker (Xvnmchen texp.ntt~). aiso federally protected. <br /> <br />Over- the two yes.:- collection period native fishe5 compri!:eC ! 9 ~ of al! fi~h coliecteC. I! reil!tively high percentage <br />compared to JIUUJ;" other nvers in the Lipper Coiorado River ollsin. Evidence of nllnJrai reproouction by aU of the <br />five unprotected native fish specio:!s listed above Wll~ found. Roundtaii chub was the fifth mOSi common of the twent:: <br />species collected during tne course of the study. Evidence of rmmdtail chub reprociuction was tound in the CDOW <br />surveys of 1990-1994 at the permanent sampiine; sUllion beiow the Dove Creek Pumps. Young-of-the-year rouootail <br />chubs were collected in relatively large numbers in both 1991 and 1992. Predation from non-native fishes was not <br />thought to be a significant limiting factor in the system, Tne Bio/West Inc. smd)-' concluded that timing, duration and <br />magnitude of spills from McPhee Dam coupled with maintaining adequate base flows in the river were imponant in <br />maintaining the downstream native fishery. The study recommended that SO cfs be adopted as a mioimum flow based <br />on the original operating criteria. <br /> <br />McPhee Reservoir Fishery - McPhee Reservoir provides habitat for numerous fish species. Although the CD OW <br />initially planned to manage the reservoir as a trout fishery, their fishery management plan for the reservoir changed to <br />inciude warm water species and Kokanee salmon. Initially, only rainbow trout were stocked in the reservoir. <br />However, brown and cutthroat trout that exist in the Dolores River upstream are also found in the reservoir in low <br />numbers. Fish species stocked in the reservoir inciude the following: <br /> <br />Largemoutn OIlSS (MiC'rnpte:'u< sl\ir!loide~) <br />Sm.a\imouth bass (1v'-icrnpterue doioP'jeui) <br />Bluegill sunfish ('LePC>Tl1i~ ml\crnchi:1ls) <br />Black crappie (p.omo-.::is ne"romRc'JiRnlS) <br /> <br />j j <br />