2016-02-03_PERMIT FILE - C1981038 (2)

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42.04 APPLICATION FOR PERMIT FOR SURFACE OR UNDERGROUND MINING ACTIVITIES -- MINIMUM REQUIREMENTS FOR INFORMATION ON ENVIRONMENTAL RESOURCES. • 2.04.7 Hydrology Description. (2) Surface Water Information. (a) and (bl The- surface water information is organized in the fol- lowing fashion. The river and stream network beginning at the Colorado River is described. The North Fork of the Gunnison River characteristics follow, with streams draining [he permit area completing the stream descrip- tions. Stockponds within the permit area are next de- scribed. Finally, surface water on the mine site fa- cilities is characterized. Watershed The proposed mine plan and adjacent area lie within the Upper Main Stem of the Upper Colorado River Region in Colorado (see Figure 2.04-3 in the Surface Water Appen- dix, Volume 4). The Upper Main Stem is composed of nine major sub-basins: Middle Park, Eagle River, Roar- ing Fork, Rifle-West Divide, Grand Valley, Upper Gunni- • son, North Fork, Uncompahgre, and Whitewater. Alti- tudes range from about 4,300 feet on the Colorado River at the Colorado-Utah state line to over 14,000 feet on the Continental Divide, which follows the eastern mar- gin of the watershed. North Fork River The Upper Main Stem drains an area of 17,764 square miles upstream from U. S. Geological Survey gaging sta- tion No. 09163500, which is located 1.5 miles upstream from the Colorado-Utah state line. Average annual wa- ter yield (1951-1976) after all depletions is. 4,146,000 acre-feet (5,736 cubic feet per second [cfs]). Dis- charge at the above station has ranged from a minim~sn daily of 960 cfs on September 7, 1956, to a maximun of 56,800 cfs on June 9, 1957. High flows typically occur during May and June in re- sponse to melting snowpacks. Flow rates during this period increase five to ten times over those occurring during other months of the year producing 60 to 65 per- cent of the total annual flow. Low flows normally Revised 12/26/84 . Revised 10/01/87 42