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<br />
<br /> ALTERNATIVES IDENTIFIED FOR DETAILED ANALYSIS
<br /> STEADY FLOW FLUCTUATING FLOW
<br /> Existing
<br /> Seasonally Monthly No Action
<br /> Year-round Adjusted Volume Low Moderate High (Existing Lim~s)
<br />Minimum flow (cfs) Yearly volume 8.000 Oct-Nav 8.000 '8,000 between '5.000 '3,000 ' 1,000 Labor
<br /> prorated 8,500 Dee 7:00 am and Day-Easter
<br /> 11,000 Jan-Mar 7:00 pm 5,000
<br /> 11,500 Apr 3,000 Easter-
<br /> 18,000 May 5,000 at night 8,000 Labor Day
<br /> 11,500 July depending upon
<br /> 8,000 Aug-Sep monthly volume,
<br /> firmload,and
<br /> market conditions
<br />Allowable daily 2,000 2,000 2,000 25,000 +/-45% of mean 15,000 through 30,500 Labor
<br />change in flow between between between 6,000 or daily flow for the 22,000 Day-Easter
<br />(cfs/24 hrs) days days days 8,000 month NTE 28,500 Easter-
<br /> 12,000 Labor Day
<br />Maximum Yearly Seasonal Monthly 20,000 Based on 31,500 31,500
<br />releases (cis)' volume volumes volumes monthly Full powerplant
<br /> prorated prorated prorated volumes and capacity studied as
<br /> allowed daily a subaltemative
<br /> changes 33,200
<br />Allowable None-4- None4 None-4- 2,500 up 4,000 up Follow power Follow power
<br />ramping (cfs/hour) 1,500 down 2,500 down load up and loadS
<br /> 5,000 or 4,000
<br /> down -'
<br />Adaptive
<br />management Applies to All Mernatives
<br />including . .
<br />research and
<br />monitoring
<br />Other elements Sand pumping None
<br />potentially Beach protection
<br />applied to any Beach/habitat building flows
<br />alternative Reduced flood frequency
<br /> Modifying the spiltway gate
<br /> Lowering the target pool elevation
<br /> Multilevel intake structures
<br /> Power system adjustment
<br />
<br />II
<br />
<br />I'
<br />
<br />, In high volume release months, the allowable daily change would require higher minimum flows.
<br />2 Daily fluctuation limit of 5,000 cfs for monthly release volumes less than 600,000 acre-It; 6,000 cis for monthly release volumes of 600,000 to
<br />800,000 acre-feet; and 8,000 cfs for monthly volumes over 600,000 acre-It. _
<br />3 Maximums represent normal or routine limits and could be exceeded during high water years to avoid releases above powerplant capacity. Some
<br />operations would have the following maximum flows that would vary with different monthly volumes. For example:
<br />Low W~tRr YB;ir (8 23 m:::lt) Hi9h W;itAr YR~U (1 S man
<br />12,000 cis 22,000 cfs
<br />20,000 cfs 31,500 cfs
<br />Low Month (550000 at) Hioh Month (1 2 mafl
<br />Existing monthly volumes 9,000 cfs 20,000 cfs
<br />Low fluctuations 13,000 cis 20,000 cis
<br />Moderate fluctuations 15,000 cfs 26,000 cfs
<br />High f1uoluations 20,000 cfs 31,500 cfs
<br />
<br />Year-round
<br />Seasonally adjusted
<br />
<br />4 Adjustments would allow +/- 1,000 cfs for power system load changes.
<br />5 Approximately 8,000 cfslhour maximum.
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