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Fina] West 81k Mine 2005 Annual Hydrology Report 41 • with the exception of adding five new surface monitoring stations (Section 3.1), four new spring monitoring stations (Section 3.2), and four new monitoring wells (Section 3.3). MCC revised the comprehensive hydrologic monitoring plan as part of the South of the Divide Permit Revision 10 (PR-10) Application (MCC, 2006b). The changes to the monitoring plan were made in anticipation of future mine development in the South of the Divide and West Flatiron areas. The new hydrologic monitoring plan includes new surface and ground water monitoring sites along with baseline monitoring. The new monitoring program considers future mining plans, mine development progress, and the mine's surface water augmentation plan. 6.1 Mining Related Hydrologic Impacts Since 1944, there have been no mining related hydrologic impacts reported in surface water or spring resources in the western Project Area, specifically the Gribble Gulch area (WWE, 2001, HydroGeo, 2002, HydroGeo 2003, HydroGeo, 2004, and HydroGeo, 2005). Gribble Gulch was undermined from 1995 to 1997, therefore, future mining related hydrologic impacts in this area are not anticipated. In WY 2005 the West Elk Mine hydrologic monitoring program was conducted in accordance with • all permit and contractual stipulations. The data collected were adequate to assess potential Project-induced impacts to the area's hydrologic system, with the exception of data collected at three surface water stream stations and five monitoring wells. The data collected from the Upper Deep Creek, Lower Deep Creek, and Upper Dry Fork surface water monitoring stations in WY 2005 are not reliable, due to naturally occurring erosion and sediment deposition resulting in continuously changing stream bed characteristics. Pressure transducers and data loggers were installed in the open stream channels at the Deep Creek stations. Control channel sections were established at each site in 1996, however flumes were not installed at these locations in order to limit impacts based on U.S. Forest Service concerns. The Deep Creek stream channel is very dynamic and has changed considerably since the sites were established. As a result of erosion and sediment deposition, the control channels used to calibrate the pressure transducers and gauge the stream flows aze constantly changing and the flow data collected for Deep Creek in WY 2002 (HydroGeo, 2003), WY 2003 (HydroGeo, 2004), WY 2004 (HydroGeo, 2005), and WY 2005 are not considered reliable. The data and graphs presented in this report were developed using a rating curve developed from recent channel geometries but the raw data for these stations remains suspect. September 2006 HydioGeq InC.