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-46- 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 Springs 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 percent of the stream flow for the Mt. Gunnison life-of-mine area during the dry part of the year. In a worst-case scenario, where all of the springs dry up, 6.2 percent of the low flow runoff could be lost. In reality, it is probable that not all the springs would be affected and, therefore, reduction of surface flow would be less than the worst-case scenario. The accuracy of WE CC's predictions, and significance of the results will be determined if WECC ever decided to request approval to mine these area. A loss of spring flow may not entirely be lost to the hydrologic system. It may temporarily become a part of the ground water system and eventually reemerge at the surface. It is difficult to predict where this water may reemerge. It could reemerge downstream in the same drainage (the Minnesota Creek system), or it could reemerge along the North Fork of the Gunnison after flowing through the mine workings. In the latter case, the impact upon water users located along Minnesota Creek is potentially the greatest. In either case, flow below the confluence of Minnesota Creek and the North Fork of the Gunnison should not be affected. Withdrawal of Water from the North Fork of the Gunnison for Mine Use Stream flows may also be depleted through the withdrawal of water from the stream or the alluvium of the stream for use in the mining operations. :.