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-41- The Somerset operation will undermine a perennial stream, and one mining operation, Blue Ribbon will be mining adjacent to a perennial drainage tributary to the North Fork of the Gunnison. Both the Blue Ribbon and the Somerset mines have surface facilities and underground mine workings located in the Hubbard Creek Drainage. The combined mining operations of the Blue Ribbon and Somerset mines may impact the quality of surface water flowing in Hubbard Creek and in the irrigation ditches supplied by Hubbard Creek. The quantity of flow may be depleted through the dewatering of faults, fractures and rock strata which are in direct or in indirect communication with the alluvium or stream bottom of Hubbard Creek. The Somerset Mine has mined beneath Hubbard Creek. Inspection of the underground workings by CMLRD hydrologists showed this portion of the mine to be making significant amounts of water. At the present time it is uncertain whether or not surface flows are being depleted. However, there is a greater concentration of inflows and increased discharges associated with the inflow in the Somerset mine workings below Hubbard Creek. The Mt. Gunnison application proposed a subsidence protection plan for the Dry Fork of Minnesota Creek to protect streamflow. The adequacy of this protection plan was not assessed as a part of the Mt. Gunnison Mine permit review (this area lies outside of the current five year permit area). The Division stipulated that site-specific monitoring data concerning subsidence and its hydrologic effects be taken into account in the design of any protection plan. Three perennial streams cross the southern portion of the Mt. Gunnison life-of-mine area: Lick Creek, South Prong, and Horse Creek. Subsidence effects could be significant along these stream courses as well, unless WECC develops and institutes subsidence protection plans for these drainages as well as Dry Fork. Depletion of Seeps and Sprinos Underground mining, even in the absence of subsidence, could cause flow from intermittent and perennial springs to be depleted, or even to go completely dry. The significance of this effect depends upon the use of the spring water and its contribution to flow in receiving streams. Underground mining at the Mt. Gunnison Mine has a high potential for affecting springs located in Sylvester Gulch. However, flow from these springs is already diverted into the Tony Bear Pipeline which is now owned by West Elk Coal Company. Most of this water is not used and flows back into the North Fork River. The Mt. Gunnison permit application identified numerous springs in or adjacent to the area to be mined. The application indicates that springs contribute 11 percent of the flow in Lower Dry Fork, 4 percent of the flow in Lick Creek, 12.6 percent of the flow in South Prong, and 0.9 percent of the flow in Horse Creek. Excluding the Sylvester Gulch data, springs could contribute 6.2