PERMFILE137694 - Laserfiche WebLink

Home Browse Search

Coal Methane Drainage Projeet - Panek 16-24 Wetf E!k Mine movement features identified as NSO areas. The CSU stipulations specify engineered designs and appropriate surface mitigation measures to minimi>e the potential Eor 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 Agriculmte. 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 azea and the Town of Somerset. North Fork water is used primarily for downstream irrigation in late summer and fall. The project area encompasses portions of four watersheds, all of which are tributary to the North Fork: • Sylvester Gulch and its tributaries, which is directly tributary to the North Fork (all Panels except 18, 19 and 20) ~ • Box Canyon, which is directly tributary to the North Fork (Panels 18, 19, 20 and portions of 21 and 22) ' • Raven Gulch, including Deep Creek and minor tributaries (portions of Panels 16, 17, 17S, and ]9 through 24) • Tributazies to the Dry Fork of Minnesota Creek (Panel 17S) ' With the exception of Deep Creek, which is a perennial stream in the southeast portion of the project area, drainages within the project area are ephemeral of 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 neaz 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-minutg baseline conditions for MCC's CDMG Permit as a basis for evaluating any changes in North Fork water quality resulting from discharges 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 increase 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 area comes Erom seeps and springs. Seeps and springs originate Erom either shallow perched ground tables or from bedrock outcrops. Dischazge data for the mine permit has been collected from approximately 83 springs. Approximately [wo-thirds of the springs emanate from colluvium and shallow ground water sources. Key characteristics of shallow groundwater are described in Section 3.1.1.4. Nearly all of the bedrock springs in this area are in the Bazren Member of the Mesa Verde Formation. These springs exhibit seasonal fluctuations in flow, though not as Environmental Atrertmen! W.uT/n1...ra. Cr WEn/tMh ~/+/o~Er LrfFt 1/3/N 6