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Stream Channel Parameters and Changes <br />Exhibit 55B Due to Longwall Mining-Induced Subsidence Page 5 <br /> <br /> <br /> <br />831-032.923 Wright Water Engineers, Inc. <br />December 2021 <br />Fork). Basin 37 is Deep Creek, a tributary to Raven Creek, which is a tributary to the North Fork. <br />Basins 38 and 39 are within the South Prong watershed, tributary to the East Fork of Minnesota <br />Creek. Basin 41 is Lion Gulch, a tributary to Minnesota Creek. <br />This report evaluates the extent of potential subsidence due to mining of the B-seam in longwall <br />panels LWB26 through LWB29 within the Southern Panels mining area and the E-seam longwall <br />panels LWE10 through LWE12 in the Apache Rocks West mining area. Finally, this report <br />assesses potential subsidence over panels LWE14, and LWSS1 through LWSS4 in the Sunset Trail <br />mining area. All panel layouts evaluated in this exhibit are shown in Figure 1. <br />As of December 2020, MCC had completed mining in E-seam longwall panels in LWE1 through <br />LWE8. LWSS1 has been mostly mined. LWE14, LWSS2, LWSS3, and LWSS4 have not yet <br />been mined. This exhibit assesses potential subsidence over portions of these unmined and <br />partially mined panels, depending on the location of the study reach. As of December 2021, <br />mining of longwall panel LWSS1 has been completed and panel LWSS2 is approximately one- <br />half completed. <br />Table 1 identifies streams that may be impacted by the proposed mining. The mining area <br />encompasses portions of 20 separate minor tributaries of the Dry Fork, Lick Creek, South Prong <br />and Deep Creek in the study area. Table 1 lists the basins and whether or not they are potentially <br />impacted by proposed mining. This study focuses on a detailed evaluation of the potential <br />subsidence impacts to 7 representative basins overlying the existing and/or proposed longwall <br />mining. A detailed discussion of the mine plan and projected subsidence for these areas is given <br />in Exhibit 60E. <br />The first portion of this hydraulic and hydrologic evaluation establishes pre-mining, or baseline, <br />conditions. The second portion of this evaluation describes the potential and likely impacts of <br />mining operations on the surface drainage system and channel characteristics.