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Table 72 B, NMD Recharge Time Estimate, provides the number of days it would take to fill in the additional <br />fracture volume resulting from subsiding the bedrock. Again, it should be recognized that this is a very <br />conservative estimate, due to the character of the stream. The data presented assumes that sandstone bedrock <br />can be found along the entire length of Fish Creek overlying the panels, and this is not the case. The section in <br />which the sandstone unit is exposed is the approximate 1,260 feet of channel in Section 10, T5N, R86W. The <br />remainder of the channel is alluvial material overlying the Lewis Shale. Given the nature of the shale, it will <br />swell to fill-in any cracks that may occur. The amount of time necessary to fill-in the additional fracture <br />volume varies from 0.6 days to 17.4 days for Panel 13 -Right, depending on the time of year mining and <br />subsequent subsidence occurs. For Panel 14 -Right, the amount of time required to fill the fracture volume <br />varies from 0.3 to 7.9 days, Panel 15 -Right varies from 0.2 to 6.2 days, and Panel 16 -Right varies from 0.2 to <br />6.8 days. <br />TCC is the immediate downstream user of irrigation water, and does not foresee any impacts to its agricultural <br />operations due to any potential loss of water from the system. In the event that significant losses occur during <br />the irrigation season, TCC has sufficient water rights under its approved Augmentation Plan to augment any <br />loss. In reference to water quality impacts, the ongoing downstream monitoring at Station 900 on Foidel Creek <br />does not show any changes that can be attributed to subsidence over Panels 8- and 9 -Right. Refer to TCC's <br />1996, 1997, and 1998 Annual Hydrology Reports for relevant data. Table 37A, Foidel Creek Flow Analysis <br />after Subsidence in the EMD, shows that water is not being lost to segments of Foidel Creek that have been <br />undermined and subsided in the EMD. This is based on comparing Site 800 plus ponds to Site 900. The Site 8 <br />data is not being used in the comparison, due to the discrepancy in the data for Site 800 and Ponds B, D, E, F, <br />and G. The total flow from Site 800 plus the ponds should approximate the flow recorded at Site 8. TCC is <br />investigating the discrepancy and will make changes to Site 8 as needed. <br />In order to validate that no impacts will be realized to AVF areas downstream of its operations, TCC will <br />continue to monitor the current downstream surface and alluvial water monitoring stations. These stations are <br />presented on Map 13A, Hydrologic Monitoring Program. The stations will be monitored consistent with the <br />•existing monitoring schedule. These stations are located along Fish Creek in Section 5, T5N, R86W. In <br />addition to the current hydrologic monitoring program, TCC will initiate a program directed at the segment of <br />Fish Creek to be impacted by mining in the NMD. This environmental program is presented in Exhibit 4e-7, <br />NMD- Fish Creek AVF Monitoring Program. The program includes the following components: hydrologic <br />monitoring, vegetation monitoring, and subsidence surveying. <br />NMD and WMD (17 through 21 Right, and 13- through 16 -Left; PR03-06 and PR09-08) <br />TCC's mining operation will result in subsiding portions of Fish Creek and its associated AVF. Potential <br />impacts to the associated ranches are described in the following paragraphs. The ranches are shown on Map 1 B. <br />Given the fact that the valley floor will subside, parts of the area will be flooded. TCC is not proposing any <br />reclamation activities for the flooded areas. The extent of flooding and loss of acreage is described in the <br />following paragraphs. The extent of flooding is controlled by the elevation overlying the gateroads and bank <br />height immediately upstream from that point. In reference to subsidence impacts to Fish Creek, TCC submits <br />that its mining operations will not impact enough of the valley floor to be significant to the existing Camilletti & <br />Sons, State of Colorado, or Cross -Mountain Ranch ranching operations. The valley floor is used exclusively as <br />rangeland, and is not currently flood -irrigated for cropping. <br />There are no established irrigation ditches along Fish Creek which irrigate designated AVF areas within the <br />limits of Longwall Panels 17- and 18 -Right or Panels 13- through 16 -Left. This reflects the fact that it is not <br />economically feasible to establish an irrigation system for the limited alluvial areas along the margins of the <br />meandering Fish Creek. Given the extensive irrigation systems established for other nearby lands when the <br />surrounding area was originally settled and developed, it is reasonable to conclude that this segment of Fish <br />Creek is not conducive to flood irrigation. The alternate to flood -irrigation is the utility of sub -irrigation to <br />•enhance crop production. Potential for effective sub -irrigation, depends on depth of rooting of selected species <br />and water -table elevation during the growing season. Data previously collected by P & M indicate that there are <br />restricted areas in which sub -irrigation does occur. The extent of sub -irrigation, based on vegetation type, was <br />verified during the 1997 growing season by vegetation production studies within the defined Fish Creek AVF. <br />PR09-08 2.06-25.4 04/29/09 <br />