Laserfiche WebLink
West Elk Mine 2007 Annual Hydrology Report 12 <br />• 3.1.1.4 North Fork Upper <br />The North Fork of the Gunnison River is a mayor perennial stream that drains the northern mine <br />area. The North Fork Upper monitoring station is at the site of the USGS gaging station (North <br />Fork Gunnison River Near Somerset, CO, USGS 09132500) located up-gradient of the mine <br />facilities area and up-gradient of the mine discharge points. The underground mine water <br />discharge flows into Sylvester Gulch then into the North Fork of the Gunnison River. The mine <br />surface water runoff is treated and routed to holding ponds and is then discharged to the North <br />Fork, if necessary. All of the mine water discharge occurs between the North Fork Upper and <br />North Fork Lower monitoring stations. <br />3.1.1.5 Sylvester Gulch (Upper. Middle. Lower) <br />Sylvester Gulch is an intermittent stream that drains the north central mine area. All of the active <br />surface facilities of the mine are located within the Sylvester Gulch drainage basin area including: <br />the main road to the mine facilities from Highway 133, the mine waste dump, the mine shop and <br />offices, the mine portal, the mine ventilation shafts, and the mine water discharge facility. The <br />three monitoring sites in Sylvester Gulch: Upper (9-inch Parshall flume and staff gage), Middle <br />(12-inch Parshall flume, staff gage, and data logger), and Lower Sylvester Gulch (no flume or data <br />• logger), monitor areas up-gradient of the mine surface facilities area, areas down-gradient of the <br />mine water discharge point and the mine facilities, and areas down-gradient of the mine spoils <br />dump, respectively. <br />3.1.2 Lower North Fork Drainage Basin Surface Water Monitoring <br />Stations <br />3.1.2.1 North Fork Lower <br />The North Fork Lower monitoring station monitors the North Fork of the Gunnison River down- <br />gradient of the mine facilities area and mine discharge points (Map 2). <br />3.1.2.2 Lower Gribble Gulch <br />Gribble Gulch is an ephemeral stream that flows only in response to storm events and spring <br />runoff. This stream drainage drains the western mine panel area. The Lower Gribble Gulch station <br />is located west of the mine, does not have a flume or data logger, and was established to monitor <br />the effects of mining in the west and northwest mine panel area. This site has been monitored since <br />1977. <br /> <br />June 2008 HydroGeo, Inc.