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• <br />• <br />• <br />19 <br />below-normal water years. In this case, the annual data were ranked from lowest to <br />highest and an 8-year interval used to select years that were drier than normal. Above- <br />and below-normal water years with moderate recurrence intervals were selected because <br />in a historical context these flows were probably important for maintaining habitats <br />relevant to razorback sucker reproduction. The 10-year recurrence interval would have <br />been ideal for this analysis, but owing to differences in the pre- and post-Flaming Gorge <br />periods of record, it was not possible to find years that met the criteria of comparable, <br />moderate return periods having similar mean annual discharges. Thus, selection of the 6- <br />year return period for wet-years and the 8-year interval for dry years was a compromise <br />to meet all of our criteria. Table 1 provides a summary of the selected water years and <br />Table 1. Water years selected to represent wet, normal, and dry conditions for the pre- <br />Flaming Gorge and Post-Flaming Gorge time periods in the Green and Yampa Rivers. <br />Numbers in parentheses are the mean annual discharges (m%) for each year. <br />Green River Yampa River <br />Condition Pre-1962 Post-1964 Pre-1962 Post-1962 <br />Above-normal 1947 (159) 1998 (157) 1952 (84) 1971 (82) <br />Normal 1956 (132) 1976 (129) 1958 (64) 1973 (68) <br />Below-normal 1955 (81) 1991 (81) 1963 (32) 1994 (32) <br />the conditions that they represent. This analysis also included 1984, although this year <br />met none of our selection criteria. During 1984, both the Green and Yampa Rivers <br />experienced the largest mean annual and peak discharges on record. This was also one of <br />few years in recent history when successful recruitment of razorback sucker has been <br />documented (Wick 1997; Modde et al. 1996). Therefore, 1984 was included in the <br />analysis because of its perceived biological importance.