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<br />Proposed Water Year 2005-2006 Experimental Actions <br /> <br />2 <br /> <br />In November 2003, the Western Area Power Administration (Wrstern) identified to <br />. . - ,I <br />members of the lWG that costs of replacement power exceeded projections identified in <br />the 2002 EA, Western proposed a modified flow regime that would reduce the cost of <br />replacement power by approximately $2 million a month and still have the desired <br />effects on non-native fish, Their modified flow regime had two components: (1) <br />increasing the duration of maximum release by two hours, from 9 hours to 11 hours each <br />day, during Monday through Saturday and (2) decreasing the fluctuations from 5,000- <br />20,000 cfs to 5,000-8,000 cfs on Sunday, The primary reason for reducing the Sunday <br />fluctuations was to compensate for additional water released during Monday through <br />Saturday, No change in ramping rates (the rate at which releases increase and decrease) <br />was proposed. A supplemental EA with a finding of no significant impact was <br />completed by the action agencies and the modified releases were implemented from <br />January-March 2004, <br /> <br />PURPOSE AND NEED FOR ACTION <br /> <br />The three agencies that proposed the 2002 EA (Reclamation, NPS, and USGS 2002) are <br />now proposing to extend the duration of the mechanical removal and non-native fish <br />suppression flows assessed in the 2002 EA and subsequent supplements, and to slightly <br />modify some of the components of the Proposed Action, The original purpose and need <br />as stated in the 2002 EA is unchanged: (1) to contribute to the conservation of <br />endangered native fish, especially the humpback chub, by reducing populations of non- <br />native fish who compete with and prey on native fish in the Colorado River between <br />Glen Canyon Dam and Lake Mead; (2) to conserve fine sediments that form sandbars, <br />beaches, and habitat for YOWlg native fish by altering dam operations; and (3) to <br />improve the Lees Ferry sport fishery by reducing the overabundance of trout. 'These <br />proposals are within the constraints established by statutes (conunonly known as the <br />"Law of the River") and other applicable legal obligations, <br /> <br />The need for the Proposed Action arises because the Grand Canyon population of <br />endangered humpback chub has declined during the last decade (GCMRC 2003), and <br />fine sediment has been exported to such an extent that camping beaches and sandbars <br />continue to be washed downstream and lost (Rubin et al. 2002). The Proposed Action <br />would provide important information that will be used as additional operational and <br />physical modifications are considered regarding future operation of Glen Canyon Dam, <br /> <br />This EA is linked or tiered to the 2002 EA. It is also tiered to the Final Environmental <br />Impact Statement for the Operation of Glen Canyon Dam (Reclamation 1995). <br />