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Time Period % of Recommended % of Weighted Usable Number of <br /> 365-day Flow Rate Area Protected R2Cross <br /> year Bluehead Flannel- Criteria <br /> Sucker mouth Met <br /> Sucker <br /> April 15 to June 14 16.7% 900 cfs 94% 100% 3 of 3 <br /> (61 days) <br /> June 15 to July 14 8.2 % 400 cfs 59% 66% 3 of 3 <br /> (30 days) <br /> July 15 to August 14 8.5 % 200 cfs 30% 38% 3 of 3 <br /> (31 days) <br /> August 15 to March 58% 100 cfs 8% 12% 2 of 3 <br /> 14 (212 days) <br /> March 15 to April 8.5% 200 cfs 30% 38% 3 of 3 <br /> 14 (31 days) <br /> The initial water availability analysis demonstrated that 900 cfs is available at least 50% of the <br /> time between April 15 and June 14, so no water availability adjustment was required during that <br /> time period. The biological flow recommendation of 900 cfs was reduced to 400 cfs for the June <br /> 15 through July 14 time period because of water availability concerns. The biological flow <br /> recommendation of 900 cfs flow was further reduced to 200 cfs during the July 15 to August 14 <br /> period because of water availability concerns. The recommendation for the June 15-July 14 and <br /> July 15-August 14 time periods are designed to maintain as much as possible bluehead sucker <br /> and flannelmouth sucker habitat during a period of the year when flows are rapidly declining. <br /> The descending limb of the hydrograph occurs at the warmest time of the year when the species <br /> are most active, and when the species are attempting to put on weight to survive limited food <br /> availability during winter. <br /> The biological flow recommendation of 900 cfs was also reduced to 200 cfs for the March 15 to <br /> April 14 period because of water availability concerns. Protection of higher flows associated <br /> with the beginning of snowmelt runoff is warranted during this period because it is the beginning <br /> of the portion of the year when the sensitive fishes complete critical parts of their life cycles, <br /> including the commencement of spawning activities in early spring. <br /> The R2CROSS Method suggests that fall/winter flows should be maintained at 100 cfs, which <br /> meets two of the three of the identified critical hydraulic criteria. The flow rate of 100 cfs was <br /> not reduced to address water availability concerns, because the initial water availability analysis <br /> performed by the CWCB suggests that 100 cfs is available at least 50% of the time during the <br /> time period between August 15 and March 14. <br />