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<br />Background <br /> <br />Section 2 <br /> <br />I <br />~ <br /> <br />· No Action; , Maintain fluctuating releases and provide baseline for impact <br />comparison <br /> <br />· Maximum Power Plant Caoacitv; Permit full use of power plant capacity <br /> <br />· High Fluctuating Flows: Slightly reduce daily fluctuations from historical no- <br />, action levels <br /> <br />· Moderate Fluctuating Flows; Moderately reduce daily fluctuations from <br />historical no-action levels <br /> <br />· ,Modified Low Fluctuating Flows (Preferred Alternative): Substantially reduce <br />daily fluctuations from historic no action levels <br /> <br />· Interim Low Fluctuating Flows; Substantially reduce daily fluctuations from <br />historic no action levels; same as interim operations <br /> <br />· Existing Monthlv Volume Steady Flows:, Provide steady flows that use historic <br />monthly release strategies <br /> <br />· Seasonallv Adiusted Steady Flows; Provide steady flows on seasonal or <br />monthly basis <br /> <br />· Year-Round Steady Flows: Provide steady flows throughout the year <br /> <br />From,the No Action alternative to the restricted fluctuating and steady flow alternatives, the <br />operating flexibility at OCD is increasingly limited. The maximum allowable release rates <br />decrease, and the minimum allowable release rates increase, resulting in a narrower range <br />of dam and power plant operations. Operations are further restricted by limiting the <br />allowable daily change (daily fluctuation) in release rates. <br /> <br />The draft OCD-EIS was released by Reclamation in January 1994, and identified the <br />Modified Low Fluctuating Flow (MLFF) alternative as the preferred alternative. The draft <br />preferred altemative allowed for a maximum release rate of 20,000 cfs, a minimum release <br />rates of 5,000 cfs at night and 8,000 cfs during the day, a daily fluctuation limits of 5,000, <br />6,000 or 8,000 cfs per day depending on monthly volume, an up ramp rate of 2,500 cfs per <br />hour, and a down ramp rate of 1.500 cfs per hour. The draft preferred alternative also <br />included habitat maintenance flows, beach- and habitat-building flows4, flood frequency <br />reduction measures and endangered fish research flows, <br /> <br />After releasing the draft OCD-EIS, additional scientific information from ongoing research <br />and public comments prompted Reclamation to modify the preferred alternative in the final <br />OCD-EIS.5 The modifications to the final preferred alternative included: increasing the <br />maximum release rate from 20,000 cfs to 25,000 cfs; increasing up ramp rate from 2,500 <br />cfs per hour to 4,000 cfs per hour; and deferring endangered fish research flows. <br />According to the OCD-EIS, winter on-peak .capacity at OCD with endangered fish <br />research flows would be reduced from 1,288 MW to 945 MW, summer capacity would be <br /> <br />March 1998 <br /> <br />Western Area Power Administration 2-7 <br /> <br />