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June 30, 2008 <br />Existing Information: <br />In addition to the existing fish surveys indicated in Section 2, there are currently two studies <br />relevant to the evaluation of flows needed to protect fisheries within the pertinent segments: <br />• Grand County's Streamflow Management Plan (Phase II) (April 2008). <br />• Eagle County's Colorado River Flow Regimes Draft Report (January 2008). <br />The Grand County Streamflow Management Plan ( "GCSMP ") plan includes fish habitat <br />analyses using the PHABSIM methodology as well as channel maintenance flow needs. The <br />Eagle County Colorado River Flow Regimes report ( "ECCRFR ") includes a preliminary <br />analysis of habitat - related flows for fisheries and flows for recreational uses. The ECCRFR <br />extrapolated data from the GCSMP. The plans include information for Segments 4 and 5 and <br />for Segment 6 down to the confluence with the Eagle River. The plans also include flow <br />recommendations for Segments 4 and 5, which will be considered by the participants. Since <br />the plans were only recently released, they require further review to determine how well they <br />satisfy the data needs for the Management Plan Alternative. <br />Data Gaps: <br />The participants are not aware of any site - specific habitat information regarding flows <br />needed to protect fisheries for the portion of Segment 6 below the confluence with the Eagle <br />River and for Segment 7. USGS streamflow records are available for determining flow needs <br />using hydrologic data. Review of the Grand County and Eagle County plans will reveal <br />whether additional data gaps exist for the remaining segments. The participants expect to <br />complete their review of the GCSMP and ECCRFR by June 30, 2008 to assist in determining <br />whether and where additional data will be collected. <br />In addition, updated fisheries data is needed for all segments. CDOW expects to conduct fish <br />surveys in Segments 4, 5, 6 and (possibly) 7 during summer or fall of 2008, if flow <br />conditions allow (i.e., surveying is not possible when flows are either so high that sampling is <br />not possible or so low that surveying will significantly impact fish). <br />Additional fish surveys will likely have to be conducted in subsequent years to evaluate the <br />efficacy of any methodology selected to predict flows that are protective of the fisheries. <br />Additional water temperature monitoring may also be needed. <br />Little information is available on desired flows for wade fishing. To fill this gap, the <br />participants plan to interview commercial outfitters and CDOW game wardens. <br />Approach: <br />If needed, and funding is available, computer modeling will be used to evaluate minimum <br />and optimal fishery flows. Models that may be used include: <br />• Physical Habitat Simulation Model ( PHABSIM). <br />• Instream Flow Incremental Methodology (IFIM). <br />-15- <br />