Laserfiche WebLink
pumped from the Roadside North Portal ultimately comes from the Colorado River by way of <br />aquifers which subcrop below the alluvium of the river. In addition, the water pumped from <br />the Roadside Mine would naturally contribute to base flows in the Colorado River through <br />aquifer discharges to the river. Therefore, the mining operation should have an insignificant <br />effect on the quantity of water in the surface and groundwater systems of the Colorado River. <br />2. Monitoring of both Cottonwood and Rapid Creek since 1985 has shown minimal disturbance <br />due to subsidence. Both creeks have infrequent flow patterns. Cottonwood Creek, although a <br />major tributary to Rapid Creek, is dry by late summer. Rapid Creek is intermittent in nature. <br />Where surface cracking was observed, within a year the crack was refilled with sediment <br />from the creek channel. Minor ponding has also been observed to have taken place in the <br />subsided areas. This ponding was for a relatively short period and has disappeared. <br />Monitoring indicates that little surface flow has been lost due to subsidence in the Rapid <br />Creek Basin. <br />Twenty -five springs have been located in the Rapid Creek Basin. All of these springs are <br />outside the subsidence angle of draw. None of the springs overlie present or planned <br />underground mine workings. Mining will not affect the natural springs. <br />4. There are seven reservoirs in the Rapid Creek Basin, all outside the boundaries of the permit <br />area. The Bureau of Land Management has stated, and the Division agrees, that six will not <br />be affected by coal mining in the area. Cabin Reservoir, which is located outside of the <br />permit area, adjacent to the southeast corner of the South Portals mine plan area, could <br />possibly be impacted by subsidence if future mining were to occur within the immediately <br />adjacent portions of the permit area. However, coal extraction operations were suspended in <br />the South Portals mine area in January, 1997, and operations did not resume. Subsequently, <br />the operator filed notice of permanent cessation of operations, and the South Portals were <br />sealed. Mine workings are separated by over a mile from the reservoir, and no further mining <br />is currently proposed. Consequently, there will be no impact to Cabin Reservoir. <br />In the unlikely event that mining operations should resume, the permittee has committed on <br />page 20 -10 of the permit application to modify the subsidence control and mitigation plan as <br />necessary, prior to resumption of operations within the South Portals mine area. <br />Consumptive use of water at the Roadside Mine consists of domestic water used at the <br />surface facilities and preparation plant, mine water used at the preparation plant, applied to <br />underground roadways, and adsorbed to the coal and refuse, and water from the Highline <br />Canal used for dust suppression on surface roads. <br />Quantities of water consumed at the mine are reported annually in the Annual Hydrologic <br />Report. Quantities consumed during active operations in water year 1992 were as follows: <br />Gallnnc i ked Lncatinn i ked <br />Domestic Water 1,397,000 Surface Facilities <br />2,150,000 Preparation Plant <br />Mine Water 3,350,000 Mining <br />29 <br />