Laserfiche WebLink
2.04.7 Hydrology Description <br />and several smaller communities along the valley and mesas are also <br />sources of nutrients as the result of effluents from discharges directly into the <br />river and through the groundwater. There is little industrial use or discharge <br />of water to the North Fork, particularly in the upper part of the valley, <br />although several coal mines have operated in the past and are presently <br />operating. <br />The North Fork of the Gunnison River, into which streams draining the <br />Somerset Coal Field flow, is severely affected by human activities, primarily <br />agriculture. Coal mines in the area currently discharge fairly significant flows <br />into the river. The West Elk Mine, Bear No. 3 Mine and Bowie No. 2 Mine all <br />discharge mine water to the river. Near Somerset, the water is a calcium - <br />bicarbonate type, typical of runoff from mountain areas, and contains total <br />dissolved - solids concentrations of less than 200 mg /I (ref. Bear 2009 AHR). <br />The Applicant monitors the North Fork above and below the mine site. The <br />minimum, average and maximum TDS values recorded in the North Fork of <br />the Gunnison River below the Bowie No. 2 mine site are 50, 137 and 280 <br />mg /I respectively (ref. Bowie No. 2 Mine 2008 AHR) <br />Streams Draining Permit and Adiacent Areas <br />Three tributary watersheds have been identified within or adjacent to the <br />Permit Area: Stevens Gulch, Terror Creek and Hubbard Creek. Large <br />discharges typically occur in March through July, with peak flows occurring in <br />late April or early May. <br />The Hubbard Creek and Terror Creek drainages are characterized by steep <br />to nearly vertical canyon walls. As both creeks are perennial and tributary to <br />the North Fork, the aquatic life in the creeks is similar to that of the North <br />Fork. Riparian vegetation occurs along the immediate streambanks, <br />confined by the steep topography and narrow coiluvial /alluvial deposits within <br />the streambed. Livestock and wildlife get to the creek for water where the <br />streambanks are less steep. <br />Stevens Gulch is an perennial stream which drains an area of approximately <br />8 square miles. Stream flows occur in response to spring snowmelt and <br />precipitation events. Run -off from the Stevens Gulch drainage does reach <br />the North Fork of the Gunnison River. Topography is characterized by <br />moderately steep to rather gentle terrain with an average stream gradient of <br />11.% The Stevens Gulch monitoring station is SW -05 which is located east <br />of the Bowie No. 1 Mine reclaimed timber storage area. <br />s <br />PR -12 2.04-41 - 06/10 <br />PPRovED Ip <br />111/ 6 /l a <br />