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<br />1572 <br /> <br />a, Comparison of Nacural Resource Flow <br />Preferences to Baseline Arkansas River Flows <br />When evaluating the effect of various flows on <br />natural resource values, it is important to under- <br />stand how well baseline Arkansas River flows have <br />supported natural resource values. During some <br />periods of the year, baseline Arkansas River flows <br />are substantially differene than the preferred flows <br />for many resource values. To facilitate a compari- <br />son between baseline Arkansas River flows and <br />resource needs, rhe following hydrographs were <br />developed co illuserare flows during the 1982 co <br />1995 period, when the Fryingpan-Arkansas <br />Project was in full operation. Please nore rhat <br />flows releases ro fulfill the objectives of the annual <br />flow management releases have been subrracted <br />ftom the,e hydrographs whenevet a separate <br />accounting of rhese releases was recorded, This <br />me:lI1S that summer flow augmentation rc:leases <br />have been suberacted out of the hydrographs, <br />while releases during fall, winter, and spring <br />under the annual flow management program have <br />nOt been subrracred our of the hydcographs. <br /> <br />Two eypes of hydro graphs are presented: <br /> <br />. The firs< hydrograph illustrates baseline <br />Arkansas River flows on a year-round basis, <br />incorporating Fryingpan-Arkansas Project <br />operations. This is the same hydro graph that <br />was presented in Section IV of this chaprer. <br /> <br />. Hydrographs are also presented for the annual <br />period between July 24 and Seprember 7, <br />which has been ideneified by river managers as <br />a period of conflict between competing narural <br /> <br />resource values. The addirional detail provided <br />in these hydcographs allows the reader .to <br />examine the difference between rypical flows <br />and resource values on a dailv basis. Because <br />this period is so crirical, hydro graphs have <br />been developed for average, wer, and dry years. <br />The average hydrograph incorporates all flows <br />from the 1982 through 1994 period. 1995 <br />was excluded from the average hydcograph <br />because it was one of the wettest water years <br />on record in rhe basin. The wer year hydco- <br />graph incorporates flows during rhe wet years <br />of 1983,1984,1985, and 1995. The dry year <br />hydrograph incorporates the dry years of 1988, <br />1991, 1992, and ]994. <br /> <br />These hydrographs are ovedaid with rhe preferred <br />Bows for llariollS resOUIce values. so that [h~ read- <br />er can undersrand how well 1982,1995 flows sup- <br />poered rhose values. The final tables in rhis sec- <br />tion provide daily flow values for rhis period in <br />text format, so that the reader can determine what <br />a rypical flow would be on any given day during <br />the July 24 . Seprember 7 period. <br /> <br />The fact that the histOtic hydrograph is nor neu' <br />tral in relationship to nat.ural resource values is <br />demonstrated by examining specific flows. For <br />example, in a dry year during rhe ] 982-1995 <br />period, Haws recede ro 700 cfs on abour July 21. <br />A 700 cis How represeoes a signiflcanr departUre <br />from rhe preferred Haws of 350 d's for juvenile <br />rrour. Similarly, in a dry year during the 1982 to <br />1995 period, flows reach 500 cfs on about August <br />12. This flow that is significanclv below the 1500 <br />cfs optimum preferred by rmers on the river. <br /> <br />20 <br />