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<prior to the irrigation season) by high stream flows wish relatively Low TDS • concentrations. The natural conditions in Tuentymile Park appear to have a much greater impact on the water quality of Fish Creek. As a final note, it was observed that the irrigation ditch that diverts water from Fish Creek just upstream of the confluence of Bond Creek was in operation during the months of June and July of 1990. Little Grassy Creek Drainage. Two monitoring sites lie within the Little Grassy Creek drainage: Surface Water Site SW-S2-5, located in the southwest portion of the permit area and NPDES Discharge Point 002, also known as the Nadge impoundment. Surface water Site SLI-S2-5. Surface Nater Site SW-52-5 drains the upper reaches of little Grassy Creek which are undisturbed by mining. Review of the hydrograph of monthly flow measurements shows loner than normal flour the past four years due to drought conditions. Review of Table 19 (Appendix A) shows water at this site to be a MgCaNa-S04 type. TDS averages have been higher than normal the past four years, possibly due to loner than average annual precipitation for the same period. NPDES Discharge Point 002. Hydrographs based on weekly flow measurements ere presented in Appendix E. The hydrographs consist of two pages, the first is for data collected in 1990 only, and the second shows historical data from December 14, 1979, to September, 1990. Review of the second hydrograph shows that flaws the past four years have been lower than normal. This is also confirmed by the following table which lists the mean weekly flows for each year. 1990 YY (Water Year) = 0,076 cfs 1989YY = 0.187 cfs 1988YY = 0.055 cfs 1987NY = 0.070 cfs 1986HY = 0.568 cfs 1985CY (Calendar Year) = 1.172 cfs 1984CY = 1,439 cfs 1983CY = 0.531 cfs 1982CY = 0.547 cfs 1981CY = 0.098 cfs 1980CY = 0.990 cfs ~/ 1J LJ • I 16