2016-05-04_PERMIT FILE - C1982056 (7)

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Cross -Mountain Ranch, LLC owns property within the Permit Area that will be affected by mining of Panels 13 - through 17 -Left, and Fish Creek and its associated AVF will be affected within their property boundaries by mining of Panels 14- through 16 -Left (T5N, R87W, Sections 19, 24, and 25). As presented in Exhibit 25Z, a • total of 39.9 acres will be flooded under normal flow conditions by mining of these panels. As is the case for all the lands along Fish Creek to be undermined and subsided, no flood irrigation system has been established to increase the productivity of the land, nor are management practices established for haying this area. The land is treated as unimproved rangeland utilized for grazing by the lessee. TCC's mining and subsiding of Fish Creek and its associated AVF will not impact those AVF's located downstream of the operation. Subsidence of the valley floor above Panels 17- and 18 -Right and Panels 13 - through 16 -Left will result in the formation of pools, with pooling and flow conditions similar to those experienced in those areas overlying Panels 9 -Right in the EMD and Panels 13- through 16 -Right in the NMD. It is anticipated that the Fish Creek channel will respond in the same manner as the Foidel Creek channel (see PR03) for the entire length where it crosses Panels 17- and 18 -Right and Panels 13- through 16 -Left. The entire length of Fish Creek overlying these panels was surveyed to identify any outcrop areas. The survey showed that a rock outcrop (Fish Creek Sandstone) was exposed in approximately 1,260 feet of channel in Section 10, T5N, R86W. Surficial cracking could occur in this area, and it would be a potential site for bedrock recharge. The cover is greater over these panels, however,and has additional shale between the mined intervals and the surface. This shale is the unit over which the alluvial materials were deposited. The combination of greater depth and thicker shale deposits will minimize the potential for surficial cracking and surface water communication to occur during and after mining. Given these considerations, TCC does not anticipate any significant loss of flow in Fish Creek as a result of its mining operations. If one were to look at the worst-case of flow disruption in Fish Creek, it would be prudent to assume that the same loss as experienced in Foidel Creek would occur. Also, it should be understood that the loss would be experienced over each of the panels and not all at once, thus limiting the volume of water that would enter the • bedrock system. As presently shown on Map 23, mining will progress from the south to the north in the NMD. Panel 17 -Right is the first panel in this part of the NMD that will result in subsidence potentially impacting Fish Creek and its AVF. Fish Creek meanders over the panel for approximately 2,300 feet. Using the above - referenced relationship of stream length to recharge volume, results in approximately 14 ac -ft of water potentially recharging the bedrock. In reference to Panel 18 -Right, Fish Creek meanders over the panel for approximately 1,700 feet. This will result in approximately 10 ac -ft of water potentially recharging the bedrock. Given the volume of water that passes through the Fish Creek system, any loss during the year is not significant to the irrigation systems on lower Fish or Trout Creeks. Table 72 B, NMD Recharge Time Estimate, provides the number of days it would take to fill in the additional fracture volume resulting from subsiding the bedrock. Again, it should be recognized that this is a very conservative estimate, due to the character of the stream. The data presented assumes that sandstone bedrock can be found for the entire length of Fish Creek overlying the panels, and this is not the case. The section in which the sandstone unit is exposed is the approximate 1,260 feet of channel in Section 10, T5N, R86W. The remainder of the channel is alluvial material overlying the Lewis Shale. Given the nature of the shale, it will swell to fill in any cracks that may occur. TCC is the immediate downstream user of irrigation water, and does not foresee any impacts to its agricultural operations due to the potential loss of water from the system. In the event that significant losses occurred during the irrigation season, TCC has sufficient water rights under the approved Augmentation Plan to augment any loss. In reference to water quality impacts, the ongoing downstream monitoring at Station 900 on Foidel Creek does not show any changes that can be attributed to subsidence over Panels 8- and 9 -Right. Refer to TCC's recent Annual Hydrology Reports to review this data. • In order to validate that no impacts will be realized to the AVF downstream of its operations, TCC will continue to monitor downstream surface and alluvial water monitoring stations. These stations are presented on Map 13A, Hydrologic Monitoring Program. The stations will be monitored consistent with the existing PR09-08 2.06-25.6 09/29/09