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<br />Chapter 2.0 Description of Alternatives 13 <br /> <br /> <br />01194 <br /> <br />The No Action Alternative for water years 2003 and 2004 does not anticipate <br />beach/habitat-building t1ows, habitat maintenance flows, or endangered fish flows as <br />described in the biological opinion. Present projections during this period of drought are <br />that the Lake Powell elevation will not rise to a level that would trigger a beach/habitat- <br />building flow by October 2004. Short-term, powerplant capacity dam releases occurred <br />in November 1997, June 2000, and September 2000. The consensus of research scientists <br />working within the GCDAMP is that thus far, these habitat maintenance flow releases <br />largely have failed to achieve the objectives identiiied in the FEIS. Researchers believe <br />there is a better chance of achieving sediment conservation and native iish habitat <br />objectives if high flows are timed to be released in conjunction with tributary sediment <br />inputs (Rubin et al. 2002). This approach occurs in one of the hydrological scenarios of <br />the Proposed Action Alternative described below. <br /> <br />Endangered fish flows recommended in the biological opinion are not part of the No <br />Action Alternative during water years 2003-2004. GCMRC and the Science Advisors <br />recommend that non-native iish suppression is a priority. They believe competition and <br />predation by large populations of non-native iish preclude native iish from taking <br />advantage of potential habitat improvements brought about by dam operations. The <br />Service (2002) has agreed it may not be wise to implement the contemplated endangered <br />fish flows until non-native iish populations are suppressed and a temperature control <br />device to warm the water below the dam is in place. The Proposed Action has been <br />designed in part to reduce or suppress non-native fish populations over a two-year <br />period. <br /> <br />2.2 PROPOSED ACTION <br /> <br />The Proposed Action has two components: modification of dam operations and <br />mechanical removal of non-native fish, particularly trout. Hypotheses relating to these <br />actions and additional details are provided in a science plan developed by GCMRC <br />(2002b). The efficacy of the Proposed Action will be evaluated in April 2004, ailer two <br />years of dam operations and mechanical removal of non-native iish. <br /> <br />2.2.1 Proposed Dam Operations <br /> <br />Proposed dam operations include five types of releases in addition to ROD <br />operational flows that would occur within four hydrological scenarios over a period of <br />two water years. <br />