2008-03-31_PERMIT FILE - C1980007A (34)

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West Elk Mine Almost all bedrock springs issue from the Barren Member and all exhibit seasonal fluctuations. Most Barren Member springs either dry up or nearly dry up during the fall and winter months. The effect of wet and dry climatic cycles also affects the discharge rates of Barren Member springs. Spring discharge rates from most Barren Member springs are less than 10 gpm during the high-flow season, suggesting that these springs do not have the same high level of hydraulic communication with snowmelt and surface water as do many springs issuing from unconsolidated deposits. The general shape and the seasonal and climatic responses`of Barren Member spring hydrographs are similar to hydrographs of springs issuing from unconsolidated sediments. These facts suggest that the groundwater storage capacities of groundwater systems supporting Barren Member springs are commonly less than the storage capacities of groundwater systems supporting unconsolidated sediment springs. This spring discussion is based on a study completed by Mayo and Associates in 1999, which is included as Exhibit 18. Reservoirs and Stock Ponds Minnesota and Beaver Reservoirs are located within or near the coal lease area, although only Minnesota Reservoir is excluded from the Federal Lease and the permit area. Minnesota Reservoir is located on the Dry Fork of Minnesota Creek near the northern boundary of the South of Divide permit area. Beaver Reservoir on the East Fork of Minnesota Creek is located near the southwestern boundary of the coal lease area. Map 34 illustrates the locations of the two reservoirs. The Monument Dam and Minnesota Reservoir are located on the Dry Fork of Minnesota Creek approximately eight miles upstream of Paonia, Colorado. It is owned by the Minnesota Canal and Reservoir Company, and is used for storage of irrigation water. The dam is an earth-fill structure, 76 feet in height, with a crest length of 422 feet. The dam was originally constructed around 1900. The dam height has been raised twice since its construction; first, in approximately 1910 and again in approximately 1933 to its current height. The reservoir has a surface area of approximately 20 acres at the storage capacity of 467 acre-feet. The drainage area contributing to the reservoir is approximately 5 square miles. The reservoir generally fills during the runoff season (May through July) and is drained to a nearly empty condition by autumn. Exhibit 74 contains the information regarding Monument Dam and Minnesota Reservoir. The dam and reservoir have been under restrictive orders by the Colorado State Engineer's Office (SEO) since 1980. A restrictive order requires the reservoir be operated under specific constraints. .In the case of the Minnesota Dam and Reservoir and based upon the relevant records at the SEO Darn Safety Section, the storage in the reservoir has been limited since that time for a variety of reasons, including; inadequate spillway, seepage on the dov nstream slope of the embankment, and cracking in the crest and downstream embankment of the darn. Extensive instrumentation (including monuments, piezometers, and inclinometers) have been installed on the dam. Collected data show that there is an active landslide on the south abutment of the dam. Beaver Reservoir is located on the East Fork of Minnesota Creek approximately 3.3 miles upstream 2.04-83 Revised R'ovember 2004 PRIG, March 2006; Rev April 2006 PRIO; Rev. M73,2006 PR10; Sep. 2007 PR12; Feb. 2008 PR12