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-26- Both the Blue Ribbon and the Somerset mines have surface facilities and underground workings within the Hubbard Creek Drainage Basin. During 1980, Hubbard Creek flows ranged from 3 cfs to 130 cfs with an average flow of 31 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. 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: Four separate drainages are located within or adjacent to the Orchard Valley Mine; Terror Creek drains the eastern portion of the life-of-mine area; and East and West Roatcap Creek drain the western portion; Steven's Gulch is an ephemeral drainage between the Terror Creek and Roatcap Creek drainage basins and drains central part of the the permit area. These streams drain directly to the North Fork or are intercepted by the Fire Mountain Canal. The entire Roatcap Creek system contains no alluvial deposits due to the steep topography and overall drainage gradient. One irrigation ditch, the Overland Ditch, follows the topographic contours between the upper Roatcap Creek Drainage Basin to the upper West Muddy Creek Drainage Basin. There are many springs and numerous ponds within the permit and hydrologically adjacent area of the Orchard Valley Mine. It appears that, most of these springs and ponds are intermittent and depend upon seasonal precipitation and long-term weather patterns. The source of most of the springs appears to be related to landslide complexes, faults and fractures, areas of colluvium/alluvium where ground water has accumulated, or the discharge points at the basal contact of the Rollins sandstone and lenticular sandstones of the Mesaverde Formation. 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 5. 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. As indicated on Table 5, the hydrologic yield of Sylvester Gulch is low compared to the other watersheds. This is due to the fact that it drains an area which is lower in elevation and which has gentler slopes. The Mt. Gunnison life-of-mine area is drained by five tributaries to Minnesota Creek. East Fork, Horse Creek, South Prong, Lick Creek, and Dry Fork drain into Minnesota Creek from areas to be undermined by the Mt. Gunnison No. 1 Mine. Their slopes are generally steeper and the watersheds are at higher elevations than those tributary to the North Fork. Based upon streamflows measured in water year 1978, the water yields from these drainages are nearly an order of magnitude greater than that from Sylvester Gulch.