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in 1962. Water yields during that period have ranged from a high of <br /> 601,800 acre feet per year in water year 1984, to a low of 82,270 <br /> acre feet in water year 1977. Flow records for the North Fork of the <br /> Gunnison River near Somerset are given in Table 1 of this document. <br /> Water quality parameters for the North Fork are given in Table 2 of <br /> this document. As indicated, water in the North Fork is a calcium <br /> bicarbonate type. There are also moderate levels of sulfate and <br /> salinity averages less than 100 mg/l. <br /> The West Elk mining operation is adjacent to Sylvester Gulch, Lone <br /> Pine Gulch, and Gribble Gulch, which are ephemeral streams that <br /> flow directly to the North Fork. No flow has been observed in Lone <br /> Pine Gulch for a period of several years. Sylvester Gulch has a <br /> drainage area of 4.25 square miles. The hydrologic yield of Sylvester <br /> Gulch is low compared to the other watersheds in the West Elk <br /> life-of-mine area. This is due to the fact that it drains an area which <br /> is lower in elevation and has gentler slopes. Monitoring of Gribble <br /> Gulch, which could potentially be impacted by mining in Jumbo <br /> Mountain, began in September 1993. Most of the West Elk Mine <br /> underlies the Minnesota Creek drainage to the south. <br /> The Minnesota Creek basin is a significant drainage system occurring <br /> in the southern part of the five-year permit area, and within the <br /> life-of-mine coal lease boundary. Minnesota Creek and its tributaries <br /> drain the southern portion of the coal lease area. These tributaries <br /> include Horse Creek, South Prong, Lick Creek, Dry Fork, and East <br /> Fork. Minnesota Creek enters the North Fork of the Gunnison near <br /> Paonia. <br /> The Minnesota Creek drainage extends approximately 53.5 square <br /> miles as shown in Figure 3 of this document. The West Elk <br /> life-of-mine area is drained by five tributaries to Minnesota Creek. <br /> These tributaries include East Fork, Horse Creek, South Prong, Lick <br /> Creek, and Dry Fork. Characteristics of the drainages are given in <br /> Table 3 of this document. Lick Creek and Dry Fork average slopes <br /> are generally steeper and the watersheds are at higher elevations than <br /> [nose tributary to the North Fork. Based upon streamflows measured <br /> in water year 1978, the water yields from these drainages are nearly <br /> an order of magnitude greater than that from Sylvester Gulch. <br /> The evaluation of flow within the Minnesota Creek drainage can only <br /> be considered an approximation due to infiltration and seepage losses, <br /> seasonal variations in precipitation and potential evaporation and <br /> sampling difficulties. Nevertheless, approximately 1,000 acre-feet is <br /> annually transferred from the Little Gunnison Creek to the Dry Fork <br /> of Minnesota Creek, and the average annual flow of the East Fork of <br /> Minnesota Creek is approximately 19,920 acre-feet. Irrigation ditches <br /> annually remove about 20,000 acre-feet from Minnesota Creek. <br /> 28 <br />