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-zs- Estimated Mean Annual Runoff Drainage & Pre-Mining Post Mining Difference Post/Pre Location: AF AF AE o Good Spring Creek at Axial 1,280 1,267 =13 98.98 Taylor Creek at Mouth 112 107 ?-5 95.54 Wilson Creek near Axial 1,340 1,335 - 5 99.63 Milk Creek at Mouth 20,600 20,582 -18 99.91 Yampa River at Maybell 1,120,000 1,119,982 -18 100.00(-) Runoff in the permit area, which is diverted or detained, will continue to reach the historic drainages. A portion of the water rights held by Colowyo on Good Spring Creek may be consumed in accordance with the augmentation plan discussed in Exhibit 7 of the permit application. The increases infiltration of surface waters is not expected to recharge the ground water system. The applicant indicates that the increased soil water resulting from increased infiltration rates and an increased moisture-holding capacity will be consumed by increases evapotranspipation. The net result is that water rarely, if ever, is given the opportunity to percolate into the subsurface material. Potential Effects on Surface Water Quality General Area The water quality in the general area is extremely variable, resulting from precipitation generated runoff and minor ground water`seepage. No adverse impacts are predicted for ~,ater quality in the general area as a result of mining operations. Primary constituents of concern for water quality in the general area are total suspended soilds (TTS), total dissolved solids (TDS) and its related parameter-specific conductivity. Data reported by Parker and Turk (1981), Skogerboe and others (1979) and Bishop and others (1982) all reflect the variability in these parameters. In fact, seasonal, flow-related, and runoff-related variability is extrane for all of these parameters. Naturally occurring TSS levels in the Yampa River basin are high due to precipitation, erosive soil types, and steep drainage slopes. - TDS and specific conductivity values are also extremely variable by season and will not be impacted by the Colowyo mine. Data presented by Bishop and others (1982), previously discuss, show that the Colowyo mine will have no effect on these parameters in the short- or long-term. In fact, the Colowyo mine was left out of the analysis because of no anticipated effect. (The study by Bishop and others (1982) relied upon the discussion of Probable Hydrologic Consequences provided by the operator in the permit application to make a cumulative assessment. It made no independent assessment of the hydrologic effects of each individual mine.)