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_27_ The water of Anthracite Creek is an alkaline, moderately hard, calcium-bicarbonate type water with an average total dissolved solids concentration of 71.6 mg/1, average pH is 7.8. Total suspended solids average approximately 25 mg/1. Dissolved metal concentrations are low throughout the year, and total metal concentrations are directly related to the total suspended solids concentrations. The Hawk's Nest life-of-mine area is drained by nine ephemeral streams for which no flow records exist. Two of the gulches have had two water samples collected during 1980; once when they were flowing during snowmelt and once during a thunderstorm event. The water is alkaline with an average total dissolved solids concentration of 121 mg/1. Total suspended solids concentrations are low. There are a total of eleven springs and seeps within or adjacent to the Hawk's Nest Mine, three are perennial. The maximum total flow frrom all springs during the summer of 1982 was ]6.1 gpm. Maximum total flow increased dramatically in the summer of 1985 to 39.4 gpm. The Somerset Mine has mine workings below the surface facilities along both Elk and Bear Creeks. These streams are ephemeral and intermittent respectively, and drain directly to the North Fork. Bear Creek was perennial below the Somerset Mine's discharge point, where the stream flow was sustained by the mine discharge. Both the Blue Ribbon and the Somerset mines have surface facilities and underground workings within the Hubbard Creek Drainage Basin. Mean flow for Hubbard Creek from Manch 20, 1980, to March 14, 1986 was approximately 30.5 cfs. Minimum flow was 1.33 cfs while maximum flow was 324 cfs. The estimated annual yield for Hubbard Creek was 24,700 acre-feet/year, or 8~ of the total flow of the North Fork for the year 1980, measured at Somerset, Colorado. The water in parts of Hubbard Creek affected by mining is a sodium bicarbonate type. In a spring survey conducted at the Blue Ribbon Mine site, only one ephemeral spring was noted and mapped. This spring is located below the Blue Ribbon Mine bench. A survey of water rights records conducted by the State Water Resources Division for the Somerset Mine revealed that there are no adjudicated springs tributary to Hubbard Creek on or adjacent to the permit areas of the Blue Ribbon and Somerset mines. The current Bear and Mt. Gunnison mining operations are adjacent to Sylvester Gulch and Lone Pine Gulch, which are ephemeral streams flowing directly to the North Fork. Characteristics of the drainages are given in Table 4. No flow was observed in Lone Pine Gulch for a period of several years. Sylvester Gulch is an ephemeral stream and has a drainage area of 4.25 square miles. The hydrologic yield of Sylvester Gulch is low compared to the other watersheds in the Mt. Gunnison No. 1 life-of~nine area. This is due to the fact that it drains an area which is lower in elevation and which has gentler slopes. Most of the Mt. Gunnison No. 1 mine underlies the Minnesota Creeki drainage to the south. ~ I