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<br />season (July and August), the project would have little and <br />frequently zero impact on Gunnison flows, since the Tunnel would <br />consequently be full. The table below highlights effects of the <br />increased diversions from 1985 to 1989 (compared to the 1932-1983 <br />average) : <br /> <br />Additional hydrorelated diversions <br />for hydropower from the Gunnison River <br />(alternatives B, E, and F; ft'/s) <br /> <br /> 1932-1983 <br /> Averaqe 1985 1986 1987 1988 1989 <br />June 286 557' 364' 152 0 0 <br />July 162 0 199 0 0 0 <br />August 173 0 5 94 0 0 <br /> <br />l spring runoff in 1985 and 1986 was unusually high, allowing UVWUA to rely <br />more heav~ly on Uncompahgre versus Gunnison flows. Thus, diversions in these months <br />do not represent normal conditions. <br /> <br />This hydrologic situation was reviewed while creating the <br />hydrologic model for the project when it was determined that the <br />best path would be to base impact assessment on the historical <br />UVWUA diversions, without adjustment for recent trends. The <br />reason for this decision was twofold: first, no guarantee exists <br />that recent trends will continue and future cropping patterns may <br />revert to the 32-year historical average at any time; second, <br />while the Tunnel can now carry more water than it could during <br />much of the study period, there is no way of knowing to what <br />extent the UVWUA would have used (and in the future will use) <br />this additional capacity. By using the historic flows during <br />1932-1983, more conservative results were attained; that is, they <br />resulted in the maximum reasonable prediction of post-project <br />reductions in Gunnison River flows. <br /> <br />The three months being considered (June through August) also <br />correspond to the peak recreation season. If recent irrigation <br />trends do continue, then most of the late summer impacts to <br />Gunnison River recreation predicted in the EIS will occur under <br />the no-action alternative as well as under the development <br />alternatives. <br /> <br />With project development, the actual impact on the Gunnison would <br />lie between the two extremes of greatest impact (as presented in <br />EIS tables and analysis) and least impact (full Tunnel use for <br />irrigation 3 months per year). By using the more conservative <br />methods, the FEIS approaches a "worst-case" analysis. The FEIS <br />has been revised to clarify this issue in the streamflow section <br /> <br />P-22 <br />