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• annual mean discharge calculated a higher annual mean for Sage Creek in comparison to Hubberson Gulch, although the drainage area for Sage Creek (7,5 square miles) is smaller than Hubberson Cu lch (8.1 square miles). The higher annual mean determined by the model for Sage Creek is largely due to the fact that Sage Creek has a higher mean basin elevation (2.67) than Hubberson Gulch (2.54). Snowmelt. Snow accumulation in watersheds draining the Seneca II-W Mine can be considerable. Snowpack storage was measured in the Hubberson Gulch watershed by conducting a series of snow surveys during the winter of 1980. The gaging was conducted at 29 stations within the Hubberson Gulch watershed, which was partitioned into 29 areas delineated by Thiessen polygons (see Figure 7-13). Each snow gaging station within each polygon was marked by a steel T-post, and gaging was performed on six occasions between January and March of 1980. The gaging was performed according to standard USDA Soil Conservation Service (SCS) techniques as outlined in Snow Survey and Water Supply Forecasting (USDA-SCS, 1972). Specifically, at each gaging site, a snow sampler was inserted vertically through the snow • until it reached the ground. The depth of the snow was recorded. The snow sampler was then pulled out of the snow and the length of the snow core obtained was recorded. Any soil caught in the end of the snow sampler was removed. Then the snow sampler containing the snow core was weighed. Care was taken to approach each gaging site from the same direction during each visit so as not to compact the snow where future samples would be collected. These data allowed for computation of the snow density and water content at each site on every survey occasion. cable 7-32 presents water contents and volumes determined from the snow gaging data collected at the 29 stations during the winter of 1980, A statistical summary of the data is provided in Table 7-33. The data in Table 7-32 indicate that the water content of the Hubberson Culch watershed increased between February 1 and March 13 to a maximum of approximately 196.31 x 106 fta. The snow wa ter 'content decreased 10 percent by the March 27 survey. Maximum snommelt occurred between April 18 and 27, and field observations revealed that all the snow in the watershed, except far a few small, isolated patches, had melted by the end of May. . The Snowpack surveyed during the winter of 1980 in Hubberson Gulch averaged 7.4 inches in water content, and the maximum water content surveyed for this basin was 9.7 inches. 95