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-z7- Three 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. Stevens Gulch is an ephemeral drainage between the Terror Creek and Roatcap Creek drainage basins which drains the permit area. Stevens Gulch has a drainage area of 6.0 square miles. Four other un-named ephemeral streams drain areas within the Orchard Valley life-of-mine area. These streams drain directly to the North Fork or 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 several springs and numerous ponds within the permit and hydrologically adjacent area of the Orchard Valley Mine. It appears that, from the data submitted to date, 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. Two reservoirs are located within the Minnesota Creek drainage. Minnesota Reservoir is located on Dry Fork. It has a decreed capacity of 1,285 acre-feet. The actual capacity may be closer to 500 acre-feet, however. Beaver Reservoir is located on the East Fork of Minnesota Creek and has an absolute decreed capacity of 1,620 acre-feet and a conditional decree of 522 acre-feet. Both reservoirs store water for irrigation purposes and are filled during spring runoff. They are usually drained by late August or early September.