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West Elk Mine <br />Fork basin, a tributary to Minnesota Creek which, in turn, is tributary to the North Fork neaz <br />`. Paonia. No portion of the Box Canyon permit revision azea is within the Dry Fork basin. All of the <br />mining operations in the Dry Fork basin, including the Apache Rocks permit revision azea, aze <br />covered by the augmentation plan. The augmentation plan did not become active until longwall <br />mining first occurred in the 12N W panel (July 1998), the first panel longwall mined, within the Dry <br />Fork drainage. The plan is based on the continuous measurement of several streams (including <br />diversions and reservoir storage volumes) to predict the expected runoff from basins above the <br />mining operations. The expected runoff is compared with actual measured runoff. If actual is less <br />than expected, MCC is required to provide augmentation water as specified in the decree. A copy <br />of the augmentation decree is provided in Exhibit 52. <br />i` <br />Mining in the Apache Rocks permit revision azea will not directly impact Minnesota Reservoir <br />because the reservoir will be outside the limits of mining influence. As discussed in Section 2.05.6 <br />(3)(b)(iii & viii), Reservoirs and Stock Ponds, MCC will maintain a very conservative setback <br />equivalent to an angle of draw of more than 25 degreesfrom the Minnesota Reservoir dam. Surface <br />inflows to Minnesota Reservoir are unlikely to be significantly affected based on analysis in Exhibit <br />52. <br />Springs that aze within the Dry Fork basin may potentially be affected by mining to the extent that <br />the flow is decreased, the flow moves, or dries up'. However, for the many reasons discussed <br />herein, these flow reductions will be modest and MCC's augmentation plan assures that no <br />downstream water users will be injured. A detailed discussion of measures taken to assess and <br />ensure the protection of the Minnesota Creek water supply is contained in Exhibit 58, Protection of <br />Minnesota Creek Water Supply. <br />The Minnesota Creek water augmentation plan was predicated upon the extremely conservative <br />assumption that all surface flows generated in the Dry Fork basin within the permit azea boundary <br />may need to be replaced, for a total annual dry year augmentation plan requirement of up to 1,250 <br />acre-feet per yeaz. The Apache Rocks permit revision area is approximately 20 percent of the <br />relevant Dry Fork acreage covered by the augmentation plan. Therefore, the current augmentation <br />plan will provide much more than adequate protection from senior water rights in the Dry Fork and <br />Minnesota Creek basins. <br />An important consideration relative to North Fork depletions is that, due to the regional dip of the <br />bedding planes, inflows from streams, springs, and/or groundwater which enters the mine workings <br />from the Dry Fork watershed could ultimately be discharged into the North Fork, rather than the <br />Dry Fork. The 1981 Minnesota Creek Protection Plan (Exhibit 58) requires MCC to return any <br />waters from the Dry Fork that enter the mine workings back to the basin. Due to the conservative <br />nature of the water augmentationplan (Exhibit 52), the potential loss of these waters from the Dry <br />Fork basin is of no consequence to downstream vested water rights as they are fully protected. <br />1 Flow from some springs never reaches a tributary stream because it is consumed by vegeta[ioq evaporates or infiltrates. <br />Reduced flow from [here springs may not affect the Flow of the basin's streams. <br />2.05-169 RevisedJun.1995PR06:ReviudNov.19987880;t/98PR08 <br />