2024-06-03_PERMIT FILE - M2023038

Home Browse Search

GBEA 13 9. Area 2 (B-2 Line #4-9) are described as having an average slope of 1.23H: 1V. Per Rule 6.3.4(1)(b) if the application proposes slopes steeper than 3:1, the Operator/Applicant must include a justification that supports steeper slopes for the proposed post-mining land use, and demonstrates compliance with the applicable performance standards of Section 3.1. Sufficient rationale has not been provided. The Wagner Pit falls within the boundary of the Twin Buttes Land Company LLC property. The high wall area is 1.21 acres and comprises 0.38 percent of the 320 acre parcel. The ratio of 1.23H:1V equals a slope of 81.3%. Additionally the pit is in the Twin Buttes, Bureau of Land Management (BIM) grazing allotment, that encompasses 158944.8 acres. A grazing allotment is defined by the BLM as : "...are areas of land designated and managed for grazing of livestock. It may include private, state, and public lands under the jurisdiction of the Bureau of Land Management and/or other federal agencies.An allotment is derived from its pastures, where the grazing of livestock is occurring." BLM (GIS) Within the area designated and managed for livestock grazing, a grid was digitized (6x7 miles at 1/2 mile intervals) and surrounds the Wagner pit. The grid, in KMZ file format, was exported into Google Earth and analyzed for slope. The following table shows the results. Note that this is presented as percent slope and not rise/run. Slope Investigation A grid of lines placed on 1/2 mile intervals Direction Of Digitizing Max 0/0 Slope Max 0/0 Slope # of Lines Range Average West to East Lines 44.8-69.2 56.31 12 North to South Lines 44 -69.1 56.85 15 3 run : 1 rise = 33.33 % Slope The placement of grid lines was such, that the fall lines of cliffs and very steep areas were not specifically selected. In all likelihood, this approach did not represent the steepest areas very well. Even so this approach shows that the maximum percent slope is well above the 33.33% of a 3/1/ (see the above table). Using ArcMap/Arcview and contours generated from 2020 LIDAR data, slopes were calculated for fall lines near the pit. Slopes were extracted from a series of rock faces 450 feet north of the pit, just above Waggoner Draw. Eight fall lines were measured over linear 800 feet of rock face. Those lines slopes averaged 336.5 %. An additional four fall lines were measured south and east of the pit, with those averaging 102.69%. All slope analysis was done in areas managed by the BLM, or on property owned by Twin Buttes Land Company,for grazing and where grazing occurs by definition. The steepest area of the High Wall averages 132% (average outside 336.5%) and the remainder 59.2% (outside range 44-69.1%). Thus, it is concluded that the current slopes of the pit and high wall areas, Wagner Pit#M2023038,Owner&Operator:Twin Buttes Land Co LLC Wednesday, May 29, 2024