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Coal Methane Drainage Project - Panek 16-24 Wett E!k Mme • Aage 3-3 movement features identified as NSO areas. The CSU stipulations specify engineered designs and appropriate surface mitigation measures to minimize the potential for slope failure and control erosion in these aeeas. Designated NSO and CSU areas are identified and delineated on Map Ml, Project Area Activities With Surface Stipulations. 3.1.1.3 Surface Water The main surface drainage in the area is the North Fork of the Gunnison River (North Fork). The North Fork is classified as Class 1 Aquatic Life Cold, Class 1 Recreation, Water Supply and Agriculture. Stream flows in the North Fork generally peak between late April and late June and flows may increase 300 percent from low flow winter discharges. Flows are controlled by releases from Paonia Reservoir upstream from the project area and the Town of Somerset. North Fork water is used primarily for downstream irrigation in late summer and fall. The project azea encompasses portions of four watersheds, all of which are tributary io the North Fork: • Sylvester Gulch and its tributaries, which is duectiy tributary to the North Foxk (all Panels except 18, 19 and 20) • Box Canyon, which is directly tributary to the North Fork (Panels ] 8, 19, 20 and portions of 21 and 22) • Raven Gulch, including Deep Creek and minor tributaries (portions of Panels 16, 17, 175, and 19 through 24) • Tributaries to the Dry Fork of Minnesota Creek (Panel 175) With the exception of Deep Creek, which is a perennial stream in the southeast portion of the project area, drainages within the project azea are ephemeral or intermittent, flowing only in response to snowmelt runoff or intense thunderstorm events. The Dry Fork of Minnesota Creek receives much of its flow from the Deep Creek Ditch, an inter-basin diversion that provides flow in Dry Fork for several additional months each yeaz. Incremental flow contributions to the North Fork from these watersheds aze a minor percentage of total annual and season flows. The USGS, in cooperation with State agencies, collects surface water data from four monitoring stations located on or near the North Fork, both upstream and downstream from the West Elk Mine. General water quality data was obtained from two of the stations and additional pazameters were available from the station located near the confluence of Sylvester Gulch and the North Fork. Data from the USGS stations were used to establish pre-mining baseline conditions for MCC's CDMG Permit as a basis for evaluating any changes in North Fork water quality resulting from dischazges at the West Elk Mine. Surface water quality in the project area is generally consistent with the North Fork. Total dissolved solids, total settleable solids, and iron concentrations can inaease dramatically during snowmelt or following intense storm events, pazticulazly in the smaller drainages. Water quality of streams can vary dramatically depending on time of year, Flows volume, and location. Some surface water in the azea comes from seeps and springs. Seeps and springs ori~ittate from either shallow perched ground tables or from bedrock outcrops. Discharge data for the mine permit has been collected from approximately 83 springs. Approximately two-thirds of the springs emanate from colluvium and shallow ground water sources. Key chazacteristics of shallow groundwater are described in Section 3.1.1.4. Neazly all of the bedrock springs in this area are vt the Barren Member of the Mesa Verde Formation. These springs exhibit seasonal flucmarions in flow, though not as EnvironmextalArtetrment b+r~/M..n+. CwG/En~r~.rp!nla>e~ vfFt i/trozm